7339 Commits

Author SHA1 Message Date
Daniel Borkmann
a8cdf34ff8 net, neigh: Enable state migration between NUD_PERMANENT and NTF_USE
[ Upstream commit 3dc20f4762c62d3b3f0940644881ed818aa7b2f5 ]

Currently, it is not possible to migrate a neighbor entry between NUD_PERMANENT
state and NTF_USE flag with a dynamic NUD state from a user space control plane.
Similarly, it is not possible to add/remove NTF_EXT_LEARNED flag from an existing
neighbor entry in combination with NTF_USE flag.

This is due to the latter directly calling into neigh_event_send() without any
meta data updates as happening in __neigh_update(). Thus, to enable this use
case, extend the latter with a NEIGH_UPDATE_F_USE flag where we break the
NUD_PERMANENT state in particular so that a latter neigh_event_send() is able
to re-resolve a neighbor entry.

Before fix, NUD_PERMANENT -> NUD_* & NTF_USE:

  # ./ip/ip n replace 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a PERMANENT
  [...]
  # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a PERMANENT
  [...]

As can be seen, despite the admin-triggered replace, the entry remains in the
NUD_PERMANENT state.

After fix, NUD_PERMANENT -> NUD_* & NTF_USE:

  # ./ip/ip n replace 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a PERMANENT
  [...]
  # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a extern_learn REACHABLE
  [...]
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a extern_learn STALE
  [...]
  # ./ip/ip n replace 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a PERMANENT
  [...]

After the fix, the admin-triggered replace switches to a dynamic state from
the NTF_USE flag which triggered a new neighbor resolution. Likewise, we can
transition back from there, if needed, into NUD_PERMANENT.

Similar before/after behavior can be observed for below transitions:

Before fix, NTF_USE -> NTF_USE | NTF_EXT_LEARNED -> NTF_USE:

  # ./ip/ip n replace 192.168.178.30 dev enp5s0 use
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a REACHABLE
  [...]
  # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a REACHABLE
  [...]

After fix, NTF_USE -> NTF_USE | NTF_EXT_LEARNED -> NTF_USE:

  # ./ip/ip n replace 192.168.178.30 dev enp5s0 use
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a REACHABLE
  [...]
  # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a extern_learn REACHABLE
  [...]
  # ./ip/ip n replace 192.168.178.30 dev enp5s0 use
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a REACHABLE
  [..]

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:04:29 +01:00
John Fastabend
c842a4c4ae bpf: sockmap, strparser, and tls are reusing qdisc_skb_cb and colliding
[ Upstream commit e0dc3b93bd7bcff8c3813d1df43e0908499c7cf0 ]

Strparser is reusing the qdisc_skb_cb struct to stash the skb message handling
progress, e.g. offset and length of the skb. First this is poorly named and
inherits a struct from qdisc that doesn't reflect the actual usage of cb[] at
this layer.

But, more importantly strparser is using the following to access its metadata.

  (struct _strp_msg *)((void *)skb->cb + offsetof(struct qdisc_skb_cb, data))

Where _strp_msg is defined as:

  struct _strp_msg {
        struct strp_msg            strp;                 /*     0     8 */
        int                        accum_len;            /*     8     4 */

        /* size: 12, cachelines: 1, members: 2 */
        /* last cacheline: 12 bytes */
  };

So we use 12 bytes of ->data[] in struct. However in BPF code running parser
and verdict the user has read capabilities into the data[] array as well. Its
not too problematic, but we should not be exposing internal state to BPF
program. If its really needed then we can use the probe_read() APIs which allow
reading kernel memory. And I don't believe cb[] layer poses any API breakage by
moving this around because programs can't depend on cb[] across layers.

In order to fix another issue with a ctx rewrite we need to stash a temp
variable somewhere. To make this work cleanly this patch builds a cb struct
for sk_skb types called sk_skb_cb struct. Then we can use this consistently
in the strparser, sockmap space. Additionally we can start allowing ->cb[]
write access after this.

Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Jussi Maki <joamaki@gmail.com>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20211103204736.248403-5-john.fastabend@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:04:27 +01:00
Jakub Kicinski
daf15fa1fd net: stream: don't purge sk_error_queue in sk_stream_kill_queues()
[ Upstream commit 24bcbe1cc69fa52dc4f7b5b2456678ed464724d8 ]

sk_stream_kill_queues() can be called on close when there are
still outstanding skbs to transmit. Those skbs may try to queue
notifications to the error queue (e.g. timestamps).
If sk_stream_kill_queues() purges the queue without taking
its lock the queue may get corrupted, and skbs leaked.

This shows up as a warning about an rmem leak:

WARNING: CPU: 24 PID: 0 at net/ipv4/af_inet.c:154 inet_sock_destruct+0x...

The leak is always a multiple of 0x300 bytes (the value is in
%rax on my builds, so RAX: 0000000000000300). 0x300 is truesize of
an empty sk_buff. Indeed if we dump the socket state at the time
of the warning the sk_error_queue is often (but not always)
corrupted. The ->next pointer points back at the list head,
but not the ->prev pointer. Indeed we can find the leaked skb
by scanning the kernel memory for something that looks like
an skb with ->sk = socket in question, and ->truesize = 0x300.
The contents of ->cb[] of the skb confirms the suspicion that
it is indeed a timestamp notification (as generated in
__skb_complete_tx_timestamp()).

Removing purging of sk_error_queue should be okay, since
inet_sock_destruct() does it again once all socket refs
are gone. Eric suggests this may cause sockets that go
thru disconnect() to maintain notifications from the
previous incarnations of the socket, but that should be
okay since the race was there anyway, and disconnect()
is not exactly dependable.

Thanks to Jonathan Lemon and Omar Sandoval for help at various
stages of tracing the issue.

Fixes: cb9eff097831 ("net: new user space API for time stamping of incoming and outgoing packets")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:04:08 +01:00
Daniel Borkmann
e29352f162 net, neigh: Fix NTF_EXT_LEARNED in combination with NTF_USE
[ Upstream commit e4400bbf5b15750e1b59bf4722d18d99be60c69f ]

The NTF_EXT_LEARNED neigh flag is usually propagated back to user space
upon dump of the neighbor table. However, when used in combination with
NTF_USE flag this is not the case despite exempting the entry from the
garbage collector. This results in inconsistent state since entries are
typically marked in neigh->flags with NTF_EXT_LEARNED, but here they are
not. Fix it by propagating the creation flag to ___neigh_create().

Before fix:

  # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a REACHABLE
  [...]

After fix:

  # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a extern_learn REACHABLE
  [...]

Fixes: 9ce33e46531d ("neighbour: support for NTF_EXT_LEARNED flag")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:04:07 +01:00
Yajun Deng
a585e04e34 net: net_namespace: Fix undefined member in key_remove_domain()
[ Upstream commit aed0826b0cf2e488900ab92193893e803d65c070 ]

The key_domain member in struct net only exists if we define CONFIG_KEYS.
So we should add the define when we used key_domain.

Fixes: 9b242610514f ("keys: Network namespace domain tag")
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:04:02 +01:00
Antoine Tenart
8524501a0e net-sysfs: try not to restart the syscall if it will fail eventually
[ Upstream commit 146e5e733310379f51924111068f08a3af0db830 ]

Due to deadlocks in the networking subsystem spotted 12 years ago[1],
a workaround was put in place[2] to avoid taking the rtnl lock when it
was not available and restarting the syscall (back to VFS, letting
userspace spin). The following construction is found a lot in the net
sysfs and sysctl code:

  if (!rtnl_trylock())
          return restart_syscall();

This can be problematic when multiple userspace threads use such
interfaces in a short period, making them to spin a lot. This happens
for example when adding and moving virtual interfaces: userspace
programs listening on events, such as systemd-udevd and NetworkManager,
do trigger actions reading files in sysfs. It gets worse when a lot of
virtual interfaces are created concurrently, say when creating
containers at boot time.

Returning early without hitting the above pattern when the syscall will
fail eventually does make things better. While it is not a fix for the
issue, it does ease things.

[1] https://lore.kernel.org/netdev/49A4D5D5.5090602@trash.net/
    https://lore.kernel.org/netdev/m14oyhis31.fsf@fess.ebiederm.org/
    and https://lore.kernel.org/netdev/20090226084924.16cb3e08@nehalam/
[2] Rightfully, those deadlocks are *hard* to solve.

Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:03:56 +01:00
Jakub Kicinski
8d433ab5c8 net: sched: update default qdisc visibility after Tx queue cnt changes
[ Upstream commit 1e080f17750d1083e8a32f7b350584ae1cd7ff20 ]

mq / mqprio make the default child qdiscs visible. They only do
so for the qdiscs which are within real_num_tx_queues when the
device is registered. Depending on order of calls in the driver,
or if user space changes config via ethtool -L the number of
qdiscs visible under tc qdisc show will differ from the number
of queues. This is confusing to users and potentially to system
configuration scripts which try to make sure qdiscs have the
right parameters.

Add a new Qdisc_ops callback and make relevant qdiscs TTRT.

Note that this uncovers the "shortcut" created by
commit 1f27cde313d7 ("net: sched: use pfifo_fast for non real queues")
The default child qdiscs beyond initial real_num_tx are always
pfifo_fast, no matter what the sysfs setting is. Fixing this
gets a little tricky because we'd need to keep a reference
on whatever the default qdisc was at the time of creation.
In practice this is likely an non-issue the qdiscs likely have
to be configured to non-default settings, so whatever user space
is doing such configuration can replace the pfifos... now that
it will see them.

Reported-by: Matthew Massey <matthewmassey@fb.com>
Reviewed-by: Dave Taht <dave.taht@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:03:53 +01:00
Cyril Strejc
b8cb3f4ffa net: multicast: calculate csum of looped-back and forwarded packets
[ Upstream commit 9122a70a6333705c0c35614ddc51c274ed1d3637 ]

During a testing of an user-space application which transmits UDP
multicast datagrams and utilizes multicast routing to send the UDP
datagrams out of defined network interfaces, I've found a multicast
router does not fill-in UDP checksum into locally produced, looped-back
and forwarded UDP datagrams, if an original output NIC the datagrams
are sent to has UDP TX checksum offload enabled.

The datagrams are sent malformed out of the NIC the datagrams have been
forwarded to.

It is because:

1. If TX checksum offload is enabled on the output NIC, UDP checksum
   is not calculated by kernel and is not filled into skb data.

2. dev_loopback_xmit(), which is called solely by
   ip_mc_finish_output(), sets skb->ip_summed = CHECKSUM_UNNECESSARY
   unconditionally.

3. Since 35fc92a9 ("[NET]: Allow forwarding of ip_summed except
   CHECKSUM_COMPLETE"), the ip_summed value is preserved during
   forwarding.

4. If ip_summed != CHECKSUM_PARTIAL, checksum is not calculated during
   a packet egress.

The minimum fix in dev_loopback_xmit():

1. Preserves skb->ip_summed CHECKSUM_PARTIAL. This is the
   case when the original output NIC has TX checksum offload enabled.
   The effects are:

     a) If the forwarding destination interface supports TX checksum
        offloading, the NIC driver is responsible to fill-in the
        checksum.

     b) If the forwarding destination interface does NOT support TX
        checksum offloading, checksums are filled-in by kernel before
        skb is submitted to the NIC driver.

     c) For local delivery, checksum validation is skipped as in the
        case of CHECKSUM_UNNECESSARY, thanks to skb_csum_unnecessary().

2. Translates ip_summed CHECKSUM_NONE to CHECKSUM_UNNECESSARY. It
   means, for CHECKSUM_NONE, the behavior is unmodified and is there
   to skip a looped-back packet local delivery checksum validation.

Signed-off-by: Cyril Strejc <cyril.strejc@skoda.cz>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:03:43 +01:00
Lorenz Bauer
b92ac0a9ca bpf: Prevent increasing bpf_jit_limit above max
[ Upstream commit fadb7ff1a6c2c565af56b4aacdd086b067eed440 ]

Restrict bpf_jit_limit to the maximum supported by the arch's JIT.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211014142554.53120-4-lmb@cloudflare.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:03:42 +01:00
Michael Chan
2b7c5eed19 net: Prevent infinite while loop in skb_tx_hash()
commit 0c57eeecc559ca6bc18b8c4e2808bc78dbe769b0 upstream.

Drivers call netdev_set_num_tc() and then netdev_set_tc_queue()
to set the queue count and offset for each TC.  So the queue count
and offset for the TCs may be zero for a short period after dev->num_tc
has been set.  If a TX packet is being transmitted at this time in the
code path netdev_pick_tx() -> skb_tx_hash(), skb_tx_hash() may see
nonzero dev->num_tc but zero qcount for the TC.  The while loop that
keeps looping while hash >= qcount will not end.

Fix it by checking the TC's qcount to be nonzero before using it.

Fixes: eadec877ce9c ("net: Add support for subordinate traffic classes to netdev_pick_tx")
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-02 19:48:22 +01:00
Xin Long
aed897e96b net-sysfs: initialize uid and gid before calling net_ns_get_ownership
commit f7a1e76d0f608961cc2fc681f867a834f2746bce upstream.

Currently in net_ns_get_ownership() it may not be able to set uid or gid
if make_kuid or make_kgid returns an invalid value, and an uninit-value
issue can be triggered by this.

This patch is to fix it by initializing the uid and gid before calling
net_ns_get_ownership(), as it does in kobject_get_ownership()

Fixes: e6dee9f3893c ("net-sysfs: add netdev_change_owner()")
Reported-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-02 19:48:22 +01:00
Eric Dumazet
9a04302252 rtnetlink: fix if_nlmsg_stats_size() under estimation
[ Upstream commit d34367991933d28bd7331f67a759be9a8c474014 ]

rtnl_fill_statsinfo() is filling skb with one mandatory if_stats_msg structure.

nlmsg_put(skb, pid, seq, type, sizeof(struct if_stats_msg), flags);

But if_nlmsg_stats_size() never considered the needed storage.

This bug did not show up because alloc_skb(X) allocates skb with
extra tailroom, because of added alignments. This could very well
be changed in the future to have deterministic behavior.

Fixes: 10c9ead9f3c6 ("rtnetlink: add new RTM_GETSTATS message to dump link stats")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Roopa Prabhu <roopa@nvidia.com>
Acked-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-13 10:04:28 +02:00
Eric Dumazet
3db53827a0 af_unix: fix races in sk_peer_pid and sk_peer_cred accesses
[ Upstream commit 35306eb23814444bd4021f8a1c3047d3cb0c8b2b ]

Jann Horn reported that SO_PEERCRED and SO_PEERGROUPS implementations
are racy, as af_unix can concurrently change sk_peer_pid and sk_peer_cred.

In order to fix this issue, this patch adds a new spinlock that needs
to be used whenever these fields are read or written.

Jann also pointed out that l2cap_sock_get_peer_pid_cb() is currently
reading sk->sk_peer_pid which makes no sense, as this field
is only possibly set by AF_UNIX sockets.
We will have to clean this in a separate patch.
This could be done by reverting b48596d1dc25 "Bluetooth: L2CAP: Add get_peer_pid callback"
or implementing what was truly expected.

Fixes: 109f6e39fa07 ("af_unix: Allow SO_PEERCRED to work across namespaces.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-06 15:55:58 +02:00
Eli Cohen
1f5db5b8a3 net: Fix offloading indirect devices dependency on qdisc order creation
[ Upstream commit 74fc4f828769cca1c3be89ea92cb88feaa27ef52 ]

Currently, when creating an ingress qdisc on an indirect device before
the driver registered for callbacks, the driver will not have a chance
to register its filter configuration callbacks.

To fix that, modify the code such that it keeps track of all the ingress
qdiscs that call flow_indr_dev_setup_offload(). When a driver calls
flow_indr_dev_register(),  go through the list of tracked ingress qdiscs
and call the driver callback entry point so as to give it a chance to
register its callback.

Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Eli Cohen <elic@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-18 13:40:30 +02:00
Gustavo A. R. Silva
863d2eb2f7 flow_dissector: Fix out-of-bounds warnings
[ Upstream commit 323e0cb473e2a8706ff162b6b4f4fa16023c9ba7 ]

Fix the following out-of-bounds warnings:

    net/core/flow_dissector.c: In function '__skb_flow_dissect':
>> net/core/flow_dissector.c:1104:4: warning: 'memcpy' offset [24, 39] from the object at '<unknown>' is out of the bounds of referenced subobject 'saddr' with type 'struct in6_addr' at offset 8 [-Warray-bounds]
     1104 |    memcpy(&key_addrs->v6addrs, &iph->saddr,
          |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     1105 |           sizeof(key_addrs->v6addrs));
          |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~
    In file included from include/linux/ipv6.h:5,
                     from net/core/flow_dissector.c:6:
    include/uapi/linux/ipv6.h:133:18: note: subobject 'saddr' declared here
      133 |  struct in6_addr saddr;
          |                  ^~~~~
>> net/core/flow_dissector.c:1059:4: warning: 'memcpy' offset [16, 19] from the object at '<unknown>' is out of the bounds of referenced subobject 'saddr' with type 'unsigned int' at offset 12 [-Warray-bounds]
     1059 |    memcpy(&key_addrs->v4addrs, &iph->saddr,
          |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     1060 |           sizeof(key_addrs->v4addrs));
          |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~
    In file included from include/linux/ip.h:17,
                     from net/core/flow_dissector.c:5:
    include/uapi/linux/ip.h:103:9: note: subobject 'saddr' declared here
      103 |  __be32 saddr;
          |         ^~~~~

The problem is that the original code is trying to copy data into a
couple of struct members adjacent to each other in a single call to
memcpy().  So, the compiler legitimately complains about it. As these
are just a couple of members, fix this by copying each one of them in
separate calls to memcpy().

This helps with the ongoing efforts to globally enable -Warray-bounds
and get us closer to being able to tighten the FORTIFY_SOURCE routines
on memcpy().

Link: https://github.com/KSPP/linux/issues/109
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/d5ae2e65-1f18-2577-246f-bada7eee6ccd@intel.com/
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-18 13:40:22 +02:00
Leon Romanovsky
2c0b826f4a devlink: Clear whole devlink_flash_notify struct
[ Upstream commit ed43fbac717882165a2a4bd64f7b1f56f7467bb7 ]

The { 0 } doesn't clear all fields in the struct, but tells to the
compiler to set all fields to zero and doesn't touch any sub-fields
if they exists.

The {} is an empty initialiser that instructs to fully initialize whole
struct including sub-fields, which is error-prone for future
devlink_flash_notify extensions.

Fixes: 6700acc5f1fe ("devlink: collect flash notify params into a struct")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15 09:50:40 +02:00
Leon Romanovsky
b376ae5597 devlink: Break parameter notification sequence to be before/after unload/load driver
[ Upstream commit 05a7f4a8dff19999ca8a83a35ff4782689de7bfc ]

The change of namespaces during devlink reload calls to driver unload
before it accesses devlink parameters. The commands below causes to
use-after-free bug when trying to get flow steering mode.

 * ip netns add n1
 * devlink dev reload pci/0000:00:09.0 netns n1

 ==================================================================
 BUG: KASAN: use-after-free in mlx5_devlink_fs_mode_get+0x96/0xa0 [mlx5_core]
 Read of size 4 at addr ffff888009d04308 by task devlink/275

 CPU: 6 PID: 275 Comm: devlink Not tainted 5.12.0-rc2+ #2853
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 Call Trace:
  dump_stack+0x93/0xc2
  print_address_description.constprop.0+0x18/0x140
  ? mlx5_devlink_fs_mode_get+0x96/0xa0 [mlx5_core]
  ? mlx5_devlink_fs_mode_get+0x96/0xa0 [mlx5_core]
  kasan_report.cold+0x7c/0xd8
  ? mlx5_devlink_fs_mode_get+0x96/0xa0 [mlx5_core]
  mlx5_devlink_fs_mode_get+0x96/0xa0 [mlx5_core]
  devlink_nl_param_fill+0x1c8/0xe80
  ? __free_pages_ok+0x37a/0x8a0
  ? devlink_flash_update_timeout_notify+0xd0/0xd0
  ? lock_acquire+0x1a9/0x6d0
  ? fs_reclaim_acquire+0xb7/0x160
  ? lock_is_held_type+0x98/0x110
  ? 0xffffffff81000000
  ? lock_release+0x1f9/0x6c0
  ? fs_reclaim_release+0xa1/0xf0
  ? lock_downgrade+0x6d0/0x6d0
  ? lock_is_held_type+0x98/0x110
  ? lock_is_held_type+0x98/0x110
  ? memset+0x20/0x40
  ? __build_skb_around+0x1f8/0x2b0
  devlink_param_notify+0x6d/0x180
  devlink_reload+0x1c3/0x520
  ? devlink_remote_reload_actions_performed+0x30/0x30
  ? mutex_trylock+0x24b/0x2d0
  ? devlink_nl_cmd_reload+0x62b/0x1070
  devlink_nl_cmd_reload+0x66d/0x1070
  ? devlink_reload+0x520/0x520
  ? devlink_get_from_attrs+0x1bc/0x260
  ? devlink_nl_pre_doit+0x64/0x4d0
  genl_family_rcv_msg_doit+0x1e9/0x2f0
  ? mutex_lock_io_nested+0x1130/0x1130
  ? genl_family_rcv_msg_attrs_parse.constprop.0+0x240/0x240
  ? security_capable+0x51/0x90
  genl_rcv_msg+0x27f/0x4a0
  ? genl_get_cmd+0x3c0/0x3c0
  ? lock_acquire+0x1a9/0x6d0
  ? devlink_reload+0x520/0x520
  ? lock_release+0x6c0/0x6c0
  netlink_rcv_skb+0x11d/0x340
  ? genl_get_cmd+0x3c0/0x3c0
  ? netlink_ack+0x9f0/0x9f0
  ? lock_release+0x1f9/0x6c0
  genl_rcv+0x24/0x40
  netlink_unicast+0x433/0x700
  ? netlink_attachskb+0x730/0x730
  ? _copy_from_iter_full+0x178/0x650
  ? __alloc_skb+0x113/0x2b0
  netlink_sendmsg+0x6f1/0xbd0
  ? netlink_unicast+0x700/0x700
  ? lock_is_held_type+0x98/0x110
  ? netlink_unicast+0x700/0x700
  sock_sendmsg+0xb0/0xe0
  __sys_sendto+0x193/0x240
  ? __x64_sys_getpeername+0xb0/0xb0
  ? do_sys_openat2+0x10b/0x370
  ? __up_read+0x1a1/0x7b0
  ? do_user_addr_fault+0x219/0xdc0
  ? __x64_sys_openat+0x120/0x1d0
  ? __x64_sys_open+0x1a0/0x1a0
  __x64_sys_sendto+0xdd/0x1b0
  ? syscall_enter_from_user_mode+0x1d/0x50
  do_syscall_64+0x2d/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xae
 RIP: 0033:0x7fc69d0af14a
 Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 76 c3 0f 1f 44 00 00 55 48 83 ec 30 44 89 4c
 RSP: 002b:00007ffc1d8292f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fc69d0af14a
 RDX: 0000000000000038 RSI: 0000555f57c56440 RDI: 0000000000000003
 RBP: 0000555f57c56410 R08: 00007fc69d17b200 R09: 000000000000000c
 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

 Allocated by task 146:
  kasan_save_stack+0x1b/0x40
  __kasan_kmalloc+0x99/0xc0
  mlx5_init_fs+0xf0/0x1c50 [mlx5_core]
  mlx5_load+0xd2/0x180 [mlx5_core]
  mlx5_init_one+0x2f6/0x450 [mlx5_core]
  probe_one+0x47d/0x6e0 [mlx5_core]
  pci_device_probe+0x2a0/0x4a0
  really_probe+0x20a/0xc90
  driver_probe_device+0xd8/0x380
  device_driver_attach+0x1df/0x250
  __driver_attach+0xff/0x240
  bus_for_each_dev+0x11e/0x1a0
  bus_add_driver+0x309/0x570
  driver_register+0x1ee/0x380
  0xffffffffa06b8062
  do_one_initcall+0xd5/0x410
  do_init_module+0x1c8/0x760
  load_module+0x6d8b/0x9650
  __do_sys_finit_module+0x118/0x1b0
  do_syscall_64+0x2d/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xae

 Freed by task 275:
  kasan_save_stack+0x1b/0x40
  kasan_set_track+0x1c/0x30
  kasan_set_free_info+0x20/0x30
  __kasan_slab_free+0x102/0x140
  slab_free_freelist_hook+0x74/0x1b0
  kfree+0xd7/0x2a0
  mlx5_unload+0x16/0xb0 [mlx5_core]
  mlx5_unload_one+0xae/0x120 [mlx5_core]
  mlx5_devlink_reload_down+0x1bc/0x380 [mlx5_core]
  devlink_reload+0x141/0x520
  devlink_nl_cmd_reload+0x66d/0x1070
  genl_family_rcv_msg_doit+0x1e9/0x2f0
  genl_rcv_msg+0x27f/0x4a0
  netlink_rcv_skb+0x11d/0x340
  genl_rcv+0x24/0x40
  netlink_unicast+0x433/0x700
  netlink_sendmsg+0x6f1/0xbd0
  sock_sendmsg+0xb0/0xe0
  __sys_sendto+0x193/0x240
  __x64_sys_sendto+0xdd/0x1b0
  do_syscall_64+0x2d/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xae

 The buggy address belongs to the object at ffff888009d04300
  which belongs to the cache kmalloc-128 of size 128
 The buggy address is located 8 bytes inside of
  128-byte region [ffff888009d04300, ffff888009d04380)
 The buggy address belongs to the page:
 page:0000000086a64ecc refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888009d04000 pfn:0x9d04
 head:0000000086a64ecc order:1 compound_mapcount:0
 flags: 0x4000000000010200(slab|head)
 raw: 4000000000010200 ffffea0000203980 0000000200000002 ffff8880050428c0
 raw: ffff888009d04000 000000008020001d 00000001ffffffff 0000000000000000
 page dumped because: kasan: bad access detected

 Memory state around the buggy address:
  ffff888009d04200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff888009d04280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 >ffff888009d04300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                       ^
  ffff888009d04380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffff888009d04400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ==================================================================

The right solution to devlink reload is to notify about deletion of
parameters, unload driver, change net namespaces, load driver and notify
about addition of parameters.

Fixes: 070c63f20f6c ("net: devlink: allow to change namespaces during reload")
Reviewed-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15 09:50:36 +02:00
Andrey Ignatov
ad0db83855 rtnetlink: Return correct error on changing device netns
[ Upstream commit 96a6b93b69880b2c978e1b2be9cae6970b605008 ]

Currently when device is moved between network namespaces using
RTM_NEWLINK message type and one of netns attributes (FLA_NET_NS_PID,
IFLA_NET_NS_FD, IFLA_TARGET_NETNSID) but w/o specifying IFLA_IFNAME, and
target namespace already has device with same name, userspace will get
EINVAL what is confusing and makes debugging harder.

Fix it so that userspace gets more appropriate EEXIST instead what makes
debugging much easier.

Before:

  # ./ifname.sh
  + ip netns add ns0
  + ip netns exec ns0 ip link add l0 type dummy
  + ip netns exec ns0 ip link show l0
  8: l0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
      link/ether 66:90:b5:d5:78:69 brd ff:ff:ff:ff:ff:ff
  + ip link add l0 type dummy
  + ip link show l0
  10: l0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
      link/ether 6e:c6:1f:15:20:8d brd ff:ff:ff:ff:ff:ff
  + ip link set l0 netns ns0
  RTNETLINK answers: Invalid argument

After:

  # ./ifname.sh
  + ip netns add ns0
  + ip netns exec ns0 ip link add l0 type dummy
  + ip netns exec ns0 ip link show l0
  8: l0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
      link/ether 1e:4a:72:e3:e3:8f brd ff:ff:ff:ff:ff:ff
  + ip link add l0 type dummy
  + ip link show l0
  10: l0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
      link/ether f2:fc:fe:2b:7d:a6 brd ff:ff:ff:ff:ff:ff
  + ip link set l0 netns ns0
  RTNETLINK answers: File exists

The problem is that do_setlink() passes its `char *ifname` argument,
that it gets from a caller, to __dev_change_net_namespace() as is (as
`const char *pat`), but semantics of ifname and pat can be different.

For example, __rtnl_newlink() does this:

net/core/rtnetlink.c
    3270	char ifname[IFNAMSIZ];
     ...
    3286	if (tb[IFLA_IFNAME])
    3287		nla_strscpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
    3288	else
    3289		ifname[0] = '\0';
     ...
    3364	if (dev) {
     ...
    3394		return do_setlink(skb, dev, ifm, extack, tb, ifname, status);
    3395	}

, i.e. do_setlink() gets ifname pointer that is always valid no matter
if user specified IFLA_IFNAME or not and then do_setlink() passes this
ifname pointer as is to __dev_change_net_namespace() as pat argument.

But the pat (pattern) in __dev_change_net_namespace() is used as:

net/core/dev.c
   11198	err = -EEXIST;
   11199	if (__dev_get_by_name(net, dev->name)) {
   11200		/* We get here if we can't use the current device name */
   11201		if (!pat)
   11202			goto out;
   11203		err = dev_get_valid_name(net, dev, pat);
   11204		if (err < 0)
   11205			goto out;
   11206	}

As the result the `goto out` path on line 11202 is neven taken and
instead of returning EEXIST defined on line 11198,
__dev_change_net_namespace() returns an error from dev_get_valid_name()
and this, in turn, will be EINVAL for ifname[0] = '\0' set earlier.

Fixes: d8a5ec672768 ("[NET]: netlink support for moving devices between network namespaces.")
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-03 10:09:25 +02:00
Willy Tarreau
8976606ca3 net: linkwatch: fix failure to restore device state across suspend/resume
[ Upstream commit 6922110d152e56d7569616b45a1f02876cf3eb9f ]

After migrating my laptop from 4.19-LTS to 5.4-LTS a while ago I noticed
that my Ethernet port to which a bond and a VLAN interface are attached
appeared to remain up after resuming from suspend with the cable unplugged
(and that problem still persists with 5.10-LTS).

It happens that the following happens:

  - the network driver (e1000e here) prepares to suspend, calls e1000e_down()
    which calls netif_carrier_off() to signal that the link is going down.
  - netif_carrier_off() adds a link_watch event to the list of events for
    this device
  - the device is completely stopped.
  - the machine suspends
  - the cable is unplugged and the machine brought to another location
  - the machine is resumed
  - the queued linkwatch events are processed for the device
  - the device doesn't yet have the __LINK_STATE_PRESENT bit and its events
    are silently dropped
  - the device is resumed with its link down
  - the upper VLAN and bond interfaces are never notified that the link had
    been turned down and remain up
  - the only way to provoke a change is to physically connect the machine
    to a port and possibly unplug it.

The state after resume looks like this:
  $ ip -br li | egrep 'bond|eth'
  bond0            UP             e8:6a:64:64:64:64 <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP>
  eth0             DOWN           e8:6a:64:64:64:64 <NO-CARRIER,BROADCAST,MULTICAST,SLAVE,UP>
  eth0.2@eth0      UP             e8:6a:64:64:64:64 <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP>

Placing an explicit call to netdev_state_change() either in the suspend
or the resume code in the NIC driver worked around this but the solution
is not satisfying.

The issue in fact really is in link_watch that loses events while it
ought not to. It happens that the test for the device being present was
added by commit 124eee3f6955 ("net: linkwatch: add check for netdevice
being present to linkwatch_do_dev") in 4.20 to avoid an access to
devices that are not present.

Instead of dropping events, this patch proceeds slightly differently by
postponing their handling so that they happen after the device is fully
resumed.

Fixes: 124eee3f6955 ("net: linkwatch: add check for netdevice being present to linkwatch_do_dev")
Link: https://lists.openwall.net/netdev/2018/03/15/62
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20210809160628.22623-1-w@1wt.eu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-18 08:59:13 +02:00
Pravin B Shelar
e8b287e783 net: Fix zero-copy head len calculation.
[ Upstream commit a17ad0961706244dce48ec941f7e476a38c0e727 ]

In some cases skb head could be locked and entire header
data is pulled from skb. When skb_zerocopy() called in such cases,
following BUG is triggered. This patch fixes it by copying entire
skb in such cases.
This could be optimized incase this is performance bottleneck.

---8<---
kernel BUG at net/core/skbuff.c:2961!
invalid opcode: 0000 [#1] SMP PTI
CPU: 2 PID: 0 Comm: swapper/2 Tainted: G           OE     5.4.0-77-generic #86-Ubuntu
Hardware name: OpenStack Foundation OpenStack Nova, BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:skb_zerocopy+0x37a/0x3a0
RSP: 0018:ffffbcc70013ca38 EFLAGS: 00010246
Call Trace:
 <IRQ>
 queue_userspace_packet+0x2af/0x5e0 [openvswitch]
 ovs_dp_upcall+0x3d/0x60 [openvswitch]
 ovs_dp_process_packet+0x125/0x150 [openvswitch]
 ovs_vport_receive+0x77/0xd0 [openvswitch]
 netdev_port_receive+0x87/0x130 [openvswitch]
 netdev_frame_hook+0x4b/0x60 [openvswitch]
 __netif_receive_skb_core+0x2b4/0xc90
 __netif_receive_skb_one_core+0x3f/0xa0
 __netif_receive_skb+0x18/0x60
 process_backlog+0xa9/0x160
 net_rx_action+0x142/0x390
 __do_softirq+0xe1/0x2d6
 irq_exit+0xae/0xb0
 do_IRQ+0x5a/0xf0
 common_interrupt+0xf/0xf

Code that triggered BUG:
int
skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen)
{
        int i, j = 0;
        int plen = 0; /* length of skb->head fragment */
        int ret;
        struct page *page;
        unsigned int offset;

        BUG_ON(!from->head_frag && !hlen);

Signed-off-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-08 09:05:23 +02:00
Cong Wang
1b148bd72e skmsg: Make sk_psock_destroy() static
[ Upstream commit 8063e184e49011f6f3f34f6c358dc8a83890bb5b ]

sk_psock_destroy() is a RCU callback, I can't see any reason why
it could be used outside.

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Cc: Lorenz Bauer <lmb@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210127221501.46866-1-xiyou.wangcong@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-04 12:46:44 +02:00
Eric Dumazet
915226f31f net: annotate data race around sk_ll_usec
[ Upstream commit 0dbffbb5335a1e3aa6855e4ee317e25e669dd302 ]

sk_ll_usec is read locklessly from sk_can_busy_loop()
while another thread can change its value in sock_setsockopt()

This is correct but needs annotations.

BUG: KCSAN: data-race in __skb_try_recv_datagram / sock_setsockopt

write to 0xffff88814eb5f904 of 4 bytes by task 14011 on cpu 0:
 sock_setsockopt+0x1287/0x2090 net/core/sock.c:1175
 __sys_setsockopt+0x14f/0x200 net/socket.c:2100
 __do_sys_setsockopt net/socket.c:2115 [inline]
 __se_sys_setsockopt net/socket.c:2112 [inline]
 __x64_sys_setsockopt+0x62/0x70 net/socket.c:2112
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88814eb5f904 of 4 bytes by task 14001 on cpu 1:
 sk_can_busy_loop include/net/busy_poll.h:41 [inline]
 __skb_try_recv_datagram+0x14f/0x320 net/core/datagram.c:273
 unix_dgram_recvmsg+0x14c/0x870 net/unix/af_unix.c:2101
 unix_seqpacket_recvmsg+0x5a/0x70 net/unix/af_unix.c:2067
 ____sys_recvmsg+0x15d/0x310 include/linux/uio.h:244
 ___sys_recvmsg net/socket.c:2598 [inline]
 do_recvmmsg+0x35c/0x9f0 net/socket.c:2692
 __sys_recvmmsg net/socket.c:2771 [inline]
 __do_sys_recvmmsg net/socket.c:2794 [inline]
 __se_sys_recvmmsg net/socket.c:2787 [inline]
 __x64_sys_recvmmsg+0xcf/0x150 net/socket.c:2787
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000 -> 0x00000101

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 14001 Comm: syz-executor.3 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-31 08:16:11 +02:00
Florian Fainelli
c9f8e17990 skbuff: Fix build with SKB extensions disabled
commit 9615fe36b31d926f1c5107013b772dc226a6a7ca upstream.

We will fail to build with CONFIG_SKB_EXTENSIONS disabled after
8550ff8d8c75 ("skbuff: Release nfct refcount on napi stolen or re-used
skbs") since there is an unconditionally use of skb_ext_find() without
an appropriate stub. Simply build the code conditionally and properly
guard against both COFNIG_SKB_EXTENSIONS as well as
CONFIG_NET_TC_SKB_EXT being disabled.

Fixes: Fixes: 8550ff8d8c75 ("skbuff: Release nfct refcount on napi stolen or re-used skbs")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-28 14:35:48 +02:00
Paul Blakey
570341f10e skbuff: Release nfct refcount on napi stolen or re-used skbs
commit 8550ff8d8c75416e984d9c4b082845e57e560984 upstream.

When multiple SKBs are merged to a new skb under napi GRO,
or SKB is re-used by napi, if nfct was set for them in the
driver, it will not be released while freeing their stolen
head state or on re-use.

Release nfct on napi's stolen or re-used SKBs, and
in gro_list_prepare, check conntrack metadata diff.

Fixes: 5c6b94604744 ("net/mlx5e: CT: Handle misses after executing CT action")
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Paul Blakey <paulb@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-28 14:35:47 +02:00
John Fastabend
715f378f42 bpf, sockmap: Fix potential memory leak on unlikely error case
[ Upstream commit 7e6b27a69167f97c56b5437871d29e9722c3e470 ]

If skb_linearize is needed and fails we could leak a msg on the error
handling. To fix ensure we kfree the msg block before returning error.
Found during code review.

Fixes: 4363023d2668e ("bpf, sockmap: Avoid failures from skb_to_sgvec when skb has frag_list")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Link: https://lore.kernel.org/bpf/20210712195546.423990-2-john.fastabend@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28 14:35:37 +02:00
Xuan Zhuo
ca9ba1de8f xdp, net: Fix use-after-free in bpf_xdp_link_release
[ Upstream commit 5acc7d3e8d342858405fbbc671221f676b547ce7 ]

The problem occurs between dev_get_by_index() and dev_xdp_attach_link().
At this point, dev_xdp_uninstall() is called. Then xdp link will not be
detached automatically when dev is released. But link->dev already
points to dev, when xdp link is released, dev will still be accessed,
but dev has been released.

dev_get_by_index()        |
link->dev = dev           |
                          |      rtnl_lock()
                          |      unregister_netdevice_many()
                          |          dev_xdp_uninstall()
                          |      rtnl_unlock()
rtnl_lock();              |
dev_xdp_attach_link()     |
rtnl_unlock();            |
                          |      netdev_run_todo() // dev released
bpf_xdp_link_release()    |
    /* access dev.        |
       use-after-free */  |

[   45.966867] BUG: KASAN: use-after-free in bpf_xdp_link_release+0x3b8/0x3d0
[   45.967619] Read of size 8 at addr ffff00000f9980c8 by task a.out/732
[   45.968297]
[   45.968502] CPU: 1 PID: 732 Comm: a.out Not tainted 5.13.0+ #22
[   45.969222] Hardware name: linux,dummy-virt (DT)
[   45.969795] Call trace:
[   45.970106]  dump_backtrace+0x0/0x4c8
[   45.970564]  show_stack+0x30/0x40
[   45.970981]  dump_stack_lvl+0x120/0x18c
[   45.971470]  print_address_description.constprop.0+0x74/0x30c
[   45.972182]  kasan_report+0x1e8/0x200
[   45.972659]  __asan_report_load8_noabort+0x2c/0x50
[   45.973273]  bpf_xdp_link_release+0x3b8/0x3d0
[   45.973834]  bpf_link_free+0xd0/0x188
[   45.974315]  bpf_link_put+0x1d0/0x218
[   45.974790]  bpf_link_release+0x3c/0x58
[   45.975291]  __fput+0x20c/0x7e8
[   45.975706]  ____fput+0x24/0x30
[   45.976117]  task_work_run+0x104/0x258
[   45.976609]  do_notify_resume+0x894/0xaf8
[   45.977121]  work_pending+0xc/0x328
[   45.977575]
[   45.977775] The buggy address belongs to the page:
[   45.978369] page:fffffc00003e6600 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4f998
[   45.979522] flags: 0x7fffe0000000000(node=0|zone=0|lastcpupid=0x3ffff)
[   45.980349] raw: 07fffe0000000000 fffffc00003e6708 ffff0000dac3c010 0000000000000000
[   45.981309] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   45.982259] page dumped because: kasan: bad access detected
[   45.982948]
[   45.983153] Memory state around the buggy address:
[   45.983753]  ffff00000f997f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   45.984645]  ffff00000f998000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   45.985533] >ffff00000f998080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   45.986419]                                               ^
[   45.987112]  ffff00000f998100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   45.988006]  ffff00000f998180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   45.988895] ==================================================================
[   45.989773] Disabling lock debugging due to kernel taint
[   45.990552] Kernel panic - not syncing: panic_on_warn set ...
[   45.991166] CPU: 1 PID: 732 Comm: a.out Tainted: G    B             5.13.0+ #22
[   45.991929] Hardware name: linux,dummy-virt (DT)
[   45.992448] Call trace:
[   45.992753]  dump_backtrace+0x0/0x4c8
[   45.993208]  show_stack+0x30/0x40
[   45.993627]  dump_stack_lvl+0x120/0x18c
[   45.994113]  dump_stack+0x1c/0x34
[   45.994530]  panic+0x3a4/0x7d8
[   45.994930]  end_report+0x194/0x198
[   45.995380]  kasan_report+0x134/0x200
[   45.995850]  __asan_report_load8_noabort+0x2c/0x50
[   45.996453]  bpf_xdp_link_release+0x3b8/0x3d0
[   45.997007]  bpf_link_free+0xd0/0x188
[   45.997474]  bpf_link_put+0x1d0/0x218
[   45.997942]  bpf_link_release+0x3c/0x58
[   45.998429]  __fput+0x20c/0x7e8
[   45.998833]  ____fput+0x24/0x30
[   45.999247]  task_work_run+0x104/0x258
[   45.999731]  do_notify_resume+0x894/0xaf8
[   46.000236]  work_pending+0xc/0x328
[   46.000697] SMP: stopping secondary CPUs
[   46.001226] Dumping ftrace buffer:
[   46.001663]    (ftrace buffer empty)
[   46.002110] Kernel Offset: disabled
[   46.002545] CPU features: 0x00000001,23202c00
[   46.003080] Memory Limit: none

Fixes: aa8d3a716b59db6c ("bpf, xdp: Add bpf_link-based XDP attachment API")
Reported-by: Abaci <abaci@linux.alibaba.com>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210710031635.41649-1-xuanzhuo@linux.alibaba.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28 14:35:37 +02:00
Aleksandr Nogikh
4a31baf55f net: add kcov handle to skb extensions
[ Upstream commit 6370cc3bbd8a0f9bf975b013781243ab147876c6 ]

Remote KCOV coverage collection enables coverage-guided fuzzing of the
code that is not reachable during normal system call execution. It is
especially helpful for fuzzing networking subsystems, where it is
common to perform packet handling in separate work queues even for the
packets that originated directly from the user space.

Enable coverage-guided frame injection by adding kcov remote handle to
skb extensions. Default initialization in __alloc_skb and
__build_skb_around ensures that no socket buffer that was generated
during a system call will be missed.

Code that is of interest and that performs packet processing should be
annotated with kcov_remote_start()/kcov_remote_stop().

An alternative approach is to determine kcov_handle solely on the
basis of the device/interface that received the specific socket
buffer. However, in this case it would be impossible to distinguish
between packets that originated during normal background network
processes or were intentionally injected from the user space.

Signed-off-by: Aleksandr Nogikh <nogikh@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28 14:35:33 +02:00
Sebastian Andrzej Siewior
3393405257 net: Treat __napi_schedule_irqoff() as __napi_schedule() on PREEMPT_RT
[ Upstream commit 8380c81d5c4fced6f4397795a5ae65758272bbfd ]

__napi_schedule_irqoff() is an optimized version of __napi_schedule()
which can be used where it is known that interrupts are disabled,
e.g. in interrupt-handlers, spin_lock_irq() sections or hrtimer
callbacks.

On PREEMPT_RT enabled kernels this assumptions is not true. Force-
threaded interrupt handlers and spinlocks are not disabling interrupts
and the NAPI hrtimer callback is forced into softirq context which runs
with interrupts enabled as well.

Chasing all usage sites of __napi_schedule_irqoff() is a whack-a-mole
game so make __napi_schedule_irqoff() invoke __napi_schedule() for
PREEMPT_RT kernels.

The callers of ____napi_schedule() in the networking core have been
audited and are correct on PREEMPT_RT kernels as well.

Reported-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-19 09:44:38 +02:00
Maciej Żenczykowski
aefa927744 bpf: Do not change gso_size during bpf_skb_change_proto()
[ Upstream commit 364745fbe981a4370f50274475da4675661104df ]

This is technically a backwards incompatible change in behaviour, but I'm
going to argue that it is very unlikely to break things, and likely to fix
*far* more then it breaks.

In no particular order, various reasons follow:

(a) I've long had a bug assigned to myself to debug a super rare kernel crash
on Android Pixel phones which can (per stacktrace) be traced back to BPF clat
IPv6 to IPv4 protocol conversion causing some sort of ugly failure much later
on during transmit deep in the GSO engine, AFAICT precisely because of this
change to gso_size, though I've never been able to manually reproduce it. I
believe it may be related to the particular network offload support of attached
USB ethernet dongle being used for tethering off of an IPv6-only cellular
connection. The reason might be we end up with more segments than max permitted,
or with a GSO packet with only one segment... (either way we break some
assumption and hit a BUG_ON)

(b) There is no check that the gso_size is > 20 when reducing it by 20, so we
might end up with a negative (or underflowing) gso_size or a gso_size of 0.
This can't possibly be good. Indeed this is probably somehow exploitable (or
at least can result in a kernel crash) by delivering crafted packets and perhaps
triggering an infinite loop or a divide by zero... As a reminder: gso_size (MSS)
is related to MTU, but not directly derived from it: gso_size/MSS may be
significantly smaller then one would get by deriving from local MTU. And on
some NICs (which do loose MTU checking on receive, it may even potentially be
larger, for example my work pc with 1500 MTU can receive 1520 byte frames [and
sometimes does due to bugs in a vendor plat46 implementation]). Indeed even just
going from 21 to 1 is potentially problematic because it increases the number
of segments by a factor of 21 (think DoS, or some other crash due to too many
segments).

(c) It's always safe to not increase the gso_size, because it doesn't result in
the max packet size increasing.  So the skb_increase_gso_size() call was always
unnecessary for correctness (and outright undesirable, see later). As such the
only part which is potentially dangerous (ie. could cause backwards compatibility
issues) is the removal of the skb_decrease_gso_size() call.

(d) If the packets are ultimately destined to the local device, then there is
absolutely no benefit to playing around with gso_size. It only matters if the
packets will egress the device. ie. we're either forwarding, or transmitting
from the device.

(e) This logic only triggers for packets which are GSO. It does not trigger for
skbs which are not GSO. It will not convert a non-GSO MTU sized packet into a
GSO packet (and you don't even know what the MTU is, so you can't even fix it).
As such your transmit path must *already* be able to handle an MTU 20 bytes
larger then your receive path (for IPv4 to IPv6 translation) - and indeed 28
bytes larger due to IPv4 fragments. Thus removing the skb_decrease_gso_size()
call doesn't actually increase the size of the packets your transmit side must
be able to handle. ie. to handle non-GSO max-MTU packets, the IPv4/IPv6 device/
route MTUs must already be set correctly. Since for example with an IPv4 egress
MTU of 1500, IPv4 to IPv6 translation will already build 1520 byte IPv6 frames,
so you need a 1520 byte device MTU. This means if your IPv6 device's egress
MTU is 1280, your IPv4 route must be 1260 (and actually 1252, because of the
need to handle fragments). This is to handle normal non-GSO packets. Thus the
reduction is simply not needed for GSO packets, because when they're correctly
built, they will already be the right size.

(f) TSO/GSO should be able to exactly undo GRO: the number of packets (TCP
segments) should not be modified, so that TCP's MSS counting works correctly
(this matters for congestion control). If protocol conversion changes the
gso_size, then the number of TCP segments may increase or decrease. Packet loss
after protocol conversion can result in partial loss of MSS segments that the
sender sent. How's the sending TCP stack going to react to receiving ACKs/SACKs
in the middle of the segments it sent?

(g) skb_{decrease,increase}_gso_size() are already no-ops for GSO_BY_FRAGS
case (besides triggering WARN_ON_ONCE). This means you already cannot guarantee
that gso_size (and thus resulting packet MTU) is changed. ie. you must assume
it won't be changed.

(h) changing gso_size is outright buggy for UDP GSO packets, where framing
matters (I believe that's also the case for SCTP, but it's already excluded
by [g]).  So the only remaining case is TCP, which also doesn't want it
(see [f]).

(i) see also the reasoning on the previous attempt at fixing this
(commit fa7b83bf3b156c767f3e4a25bbf3817b08f3ff8e) which shows that the current
behaviour causes TCP packet loss:

  In the forwarding path GRO -> BPF 6 to 4 -> GSO for TCP traffic, the
  coalesced packet payload can be > MSS, but < MSS + 20.

  bpf_skb_proto_6_to_4() will upgrade the MSS and it can be > the payload
  length. After then tcp_gso_segment checks for the payload length if it
  is <= MSS. The condition is causing the packet to be dropped.

  tcp_gso_segment():
    [...]
    mss = skb_shinfo(skb)->gso_size;
    if (unlikely(skb->len <= mss)) goto out;
    [...]

Thus changing the gso_size is simply a very bad idea. Increasing is unnecessary
and buggy, and decreasing can go negative.

Fixes: 6578171a7ff0 ("bpf: add bpf_skb_change_proto helper")
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Dongseok Yi <dseok.yi@samsung.com>
Cc: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/bpf/CANP3RGfjLikQ6dg=YpBU0OeHvyv7JOki7CyOUS9modaXAi-9vQ@mail.gmail.com
Link: https://lore.kernel.org/bpf/20210617000953.2787453-2-zenczykowski@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:56:27 +02:00
Changbin Du
4abfd597fe net: make get_net_ns return error if NET_NS is disabled
[ Upstream commit ea6932d70e223e02fea3ae20a4feff05d7c1ea9a ]

There is a panic in socket ioctl cmd SIOCGSKNS when NET_NS is not enabled.
The reason is that nsfs tries to access ns->ops but the proc_ns_operations
is not implemented in this case.

[7.670023] Unable to handle kernel NULL pointer dereference at virtual address 00000010
[7.670268] pgd = 32b54000
[7.670544] [00000010] *pgd=00000000
[7.671861] Internal error: Oops: 5 [#1] SMP ARM
[7.672315] Modules linked in:
[7.672918] CPU: 0 PID: 1 Comm: systemd Not tainted 5.13.0-rc3-00375-g6799d4f2da49 #16
[7.673309] Hardware name: Generic DT based system
[7.673642] PC is at nsfs_evict+0x24/0x30
[7.674486] LR is at clear_inode+0x20/0x9c

The same to tun SIOCGSKNS command.

To fix this problem, we make get_net_ns() return -EINVAL when NET_NS is
disabled. Meanwhile move it to right place net/core/net_namespace.c.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Fixes: c62cce2caee5 ("net: add an ioctl to get a socket network namespace")
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-23 14:42:44 +02:00
Ido Schimmel
c8f1437c01 rtnetlink: Fix regression in bridge VLAN configuration
[ Upstream commit d2e381c4963663bca6f30c3b996fa4dbafe8fcb5 ]

Cited commit started returning errors when notification info is not
filled by the bridge driver, resulting in the following regression:

 # ip link add name br1 type bridge vlan_filtering 1
 # bridge vlan add dev br1 vid 555 self pvid untagged
 RTNETLINK answers: Invalid argument

As long as the bridge driver does not fill notification info for the
bridge device itself, an empty notification should not be considered as
an error. This is explained in commit 59ccaaaa49b5 ("bridge: dont send
notification when skb->len == 0 in rtnl_bridge_notify").

Fix by removing the error and add a comment to avoid future bugs.

Fixes: a8db57c1d285 ("rtnetlink: Fix missing error code in rtnl_bridge_notify()")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-23 14:42:42 +02:00
Zheng Yongjun
808fcc1e70 fib: Return the correct errno code
[ Upstream commit 59607863c54e9eb3f69afc5257dfe71c38bb751e ]

When kalloc or kmemdup failed, should return ENOMEM rather than ENOBUF.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-18 10:00:06 +02:00
Jiapeng Chong
0aa3569508 rtnetlink: Fix missing error code in rtnl_bridge_notify()
[ Upstream commit a8db57c1d285c758adc7fb43d6e2bad2554106e1 ]

The error code is missing in this code scenario, add the error code
'-EINVAL' to the return value 'err'.

Eliminate the follow smatch warning:

net/core/rtnetlink.c:4834 rtnl_bridge_notify() warn: missing error code
'err'.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-18 10:00:06 +02:00
David Ahern
d17d47da59 neighbour: allow NUD_NOARP entries to be forced GCed
commit 7a6b1ab7475fd6478eeaf5c9d1163e7a18125c8f upstream.

IFF_POINTOPOINT interfaces use NUD_NOARP entries for IPv6. It's possible to
fill up the neighbour table with enough entries that it will overflow for
valid connections after that.

This behaviour is more prevalent after commit 58956317c8de ("neighbor:
Improve garbage collection") is applied, as it prevents removal from
entries that are not NUD_FAILED, unless they are more than 5s old.

Fixes: 58956317c8de (neighbor: Improve garbage collection)
Reported-by: Kasper Dupont <kasperd@gjkwv.06.feb.2021.kasperd.net>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-10 13:39:29 +02:00
Alexander Aring
a5de17bb91 net: sock: fix in-kernel mark setting
[ Upstream commit dd9082f4a9f94280fbbece641bf8fc0a25f71f7a ]

This patch fixes the in-kernel mark setting by doing an additional
sk_dst_reset() which was introduced by commit 50254256f382 ("sock: Reset
dst when changing sk_mark via setsockopt"). The code is now shared to
avoid any further suprises when changing the socket mark value.

Fixes: 84d1c617402e ("net: sock: add sock_set_mark")
Reported-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-10 13:39:17 +02:00
Parav Pandit
4f00f9c169 devlink: Correct VIRTUAL port to not have phys_port attributes
[ Upstream commit b28d8f0c25a9b0355116cace5f53ea52bd4020c8 ]

Physical port name, port number attributes do not belong to virtual port
flavour. When VF or SF virtual ports are registered they incorrectly
append "np0" string in the netdevice name of the VF/SF.

Before this fix, VF netdevice name were ens2f0np0v0, ens2f0np0v1 for VF
0 and 1 respectively.

After the fix, they are ens2f0v0, ens2f0v1.

With this fix, reading /sys/class/net/ens2f0v0/phys_port_name returns
-EOPNOTSUPP.

Also devlink port show example for 2 VFs on one PF to ensure that any
physical port attributes are not exposed.

$ devlink port show
pci/0000:06:00.0/65535: type eth netdev ens2f0np0 flavour physical port 0 splittable false
pci/0000:06:00.3/196608: type eth netdev ens2f0v0 flavour virtual splittable false
pci/0000:06:00.4/262144: type eth netdev ens2f0v1 flavour virtual splittable false

This change introduces a netdevice name change on systemd/udev
version 245 and higher which honors phys_port_name sysfs file for
generation of netdevice name.

This also aligns to phys_port_name usage which is limited to switchdev
ports as described in [1].

[1] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/tree/Documentation/networking/switchdev.rst

Fixes: acf1ee44ca5d ("devlink: Introduce devlink port flavour virtual")
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20210526200027.14008-1-parav@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-10 13:39:16 +02:00
Chinmay Agarwal
5c7b23b796 neighbour: Prevent Race condition in neighbour subsytem
commit eefb45eef5c4c425e87667af8f5e904fbdd47abf upstream.

Following Race Condition was detected:

<CPU A, t0>: Executing: __netif_receive_skb() ->__netif_receive_skb_core()
-> arp_rcv() -> arp_process().arp_process() calls __neigh_lookup() which
takes a reference on neighbour entry 'n'.
Moves further along, arp_process() and calls neigh_update()->
__neigh_update(). Neighbour entry is unlocked just before a call to
neigh_update_gc_list.

This unlocking paves way for another thread that may take a reference on
the same and mark it dead and remove it from gc_list.

<CPU B, t1> - neigh_flush_dev() is under execution and calls
neigh_mark_dead(n) marking the neighbour entry 'n' as dead. Also n will be
removed from gc_list.
Moves further along neigh_flush_dev() and calls
neigh_cleanup_and_release(n), but since reference count increased in t1,
'n' couldn't be destroyed.

<CPU A, t3>- Code hits neigh_update_gc_list, with neighbour entry
set as dead.

<CPU A, t4> - arp_process() finally calls neigh_release(n), destroying
the neighbour entry and we have a destroyed ntry still part of gc_list.

Fixes: eb4e8fac00d1("neighbour: Prevent a dead entry from updating gc_list")
Signed-off-by: Chinmay Agarwal <chinagar@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03 09:00:52 +02:00
Jussi Maki
9948170c8e bpf: Set mac_len in bpf_skb_change_head
[ Upstream commit 84316ca4e100d8cbfccd9f774e23817cb2059868 ]

The skb_change_head() helper did not set "skb->mac_len", which is
problematic when it's used in combination with skb_redirect_peer().
Without it, redirecting a packet from a L3 device such as wireguard to
the veth peer device will cause skb->data to point to the middle of the
IP header on entry to tcp_v4_rcv() since the L2 header is not pulled
correctly due to mac_len=0.

Fixes: 3a0af8fd61f9 ("bpf: BPF for lightweight tunnel infrastructure")
Signed-off-by: Jussi Maki <joamaki@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210519154743.2554771-2-joamaki@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-03 09:00:49 +02:00
Yunsheng Lin
f9fc21e2b1 net: sched: fix tx action reschedule issue with stopped queue
[ Upstream commit dcad9ee9e0663d74a89b25b987f9c7be86432812 ]

The netdev qeueue might be stopped when byte queue limit has
reached or tx hw ring is full, net_tx_action() may still be
rescheduled if STATE_MISSED is set, which consumes unnecessary
cpu without dequeuing and transmiting any skb because the
netdev queue is stopped, see qdisc_run_end().

This patch fixes it by checking the netdev queue state before
calling qdisc_run() and clearing STATE_MISSED if netdev queue is
stopped during qdisc_run(), the net_tx_action() is rescheduled
again when netdev qeueue is restarted, see netif_tx_wake_queue().

As there is time window between netif_xmit_frozen_or_stopped()
checking and STATE_MISSED clearing, between which STATE_MISSED
may set by net_tx_action() scheduled by netif_tx_wake_queue(),
so set the STATE_MISSED again if netdev queue is restarted.

Fixes: 6b3ba9146fe6 ("net: sched: allow qdiscs to handle locking")
Reported-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-03 09:00:47 +02:00
Yunsheng Lin
2f23d5bcd9 net: sched: fix tx action rescheduling issue during deactivation
[ Upstream commit 102b55ee92f9fda4dde7a45d2b20538e6e3e3d1e ]

Currently qdisc_run() checks the STATE_DEACTIVATED of lockless
qdisc before calling __qdisc_run(), which ultimately clear the
STATE_MISSED when all the skb is dequeued. If STATE_DEACTIVATED
is set before clearing STATE_MISSED, there may be rescheduling
of net_tx_action() at the end of qdisc_run_end(), see below:

CPU0(net_tx_atcion)  CPU1(__dev_xmit_skb)  CPU2(dev_deactivate)
          .                   .                     .
          .            set STATE_MISSED             .
          .           __netif_schedule()            .
          .                   .           set STATE_DEACTIVATED
          .                   .                qdisc_reset()
          .                   .                     .
          .<---------------   .              synchronize_net()
clear __QDISC_STATE_SCHED  |  .                     .
          .                |  .                     .
          .                |  .            some_qdisc_is_busy()
          .                |  .               return *false*
          .                |  .                     .
  test STATE_DEACTIVATED   |  .                     .
__qdisc_run() *not* called |  .                     .
          .                |  .                     .
   test STATE_MISS         |  .                     .
 __netif_schedule()--------|  .                     .
          .                   .                     .
          .                   .                     .

__qdisc_run() is not called by net_tx_atcion() in CPU0 because
CPU2 has set STATE_DEACTIVATED flag during dev_deactivate(), and
STATE_MISSED is only cleared in __qdisc_run(), __netif_schedule
is called at the end of qdisc_run_end(), causing tx action
rescheduling problem.

qdisc_run() called by net_tx_action() runs in the softirq context,
which should has the same semantic as the qdisc_run() called by
__dev_xmit_skb() protected by rcu_read_lock_bh(). And there is a
synchronize_net() between STATE_DEACTIVATED flag being set and
qdisc_reset()/some_qdisc_is_busy in dev_deactivate(), we can safely
bail out for the deactived lockless qdisc in net_tx_action(), and
qdisc_reset() will reset all skb not dequeued yet.

So add the rcu_read_lock() explicitly to protect the qdisc_run()
and do the STATE_DEACTIVATED checking in net_tx_action() before
calling qdisc_run_begin(). Another option is to do the checking in
the qdisc_run_end(), but it will add unnecessary overhead for
non-tx_action case, because __dev_queue_xmit() will not see qdisc
with STATE_DEACTIVATED after synchronize_net(), the qdisc with
STATE_DEACTIVATED can only be seen by net_tx_action() because of
__netif_schedule().

The STATE_DEACTIVATED checking in qdisc_run() is to avoid race
between net_tx_action() and qdisc_reset(), see:
commit d518d2ed8640 ("net/sched: fix race between deactivation
and dequeue for NOLOCK qdisc"). As the bailout added above for
deactived lockless qdisc in net_tx_action() provides better
protection for the race without calling qdisc_run() at all, so
remove the STATE_DEACTIVATED checking in qdisc_run().

After qdisc_reset(), there is no skb in qdisc to be dequeued, so
clear the STATE_MISSED in dev_reset_queue() too.

Fixes: 6b3ba9146fe6 ("net: sched: allow qdiscs to handle locking")
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
V8: Clearing STATE_MISSED before calling __netif_schedule() has
    avoid the endless rescheduling problem, but there may still
    be a unnecessary rescheduling, so adjust the commit log.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-03 09:00:47 +02:00
Paolo Abeni
1f1b431a4f net: really orphan skbs tied to closing sk
[ Upstream commit 098116e7e640ba677d9e345cbee83d253c13d556 ]

If the owing socket is shutting down - e.g. the sock reference
count already dropped to 0 and only sk_wmem_alloc is keeping
the sock alive, skb_orphan_partial() becomes a no-op.

When forwarding packets over veth with GRO enabled, the above
causes refcount errors.

This change addresses the issue with a plain skb_orphan() call
in the critical scenario.

Fixes: 9adc89af724f ("net: let skb_orphan_partial wake-up waiters.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-03 09:00:46 +02:00
Matthew Wilcox (Oracle)
cfddf6a685 mm: fix struct page layout on 32-bit systems
commit 9ddb3c14afba8bc5950ed297f02d4ae05ff35cd1 upstream.

32-bit architectures which expect 8-byte alignment for 8-byte integers and
need 64-bit DMA addresses (arm, mips, ppc) had their struct page
inadvertently expanded in 2019.  When the dma_addr_t was added, it forced
the alignment of the union to 8 bytes, which inserted a 4 byte gap between
'flags' and the union.

Fix this by storing the dma_addr_t in one or two adjacent unsigned longs.
This restores the alignment to that of an unsigned long.  We always
store the low bits in the first word to prevent the PageTail bit from
being inadvertently set on a big endian platform.  If that happened,
get_user_pages_fast() racing against a page which was freed and
reallocated to the page_pool could dereference a bogus compound_head(),
which would be hard to trace back to this cause.

Link: https://lkml.kernel.org/r/20210510153211.1504886-1-willy@infradead.org
Fixes: c25fff7171be ("mm: add dma_addr_t to struct page")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Matteo Croce <mcroce@linux.microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-19 10:13:17 +02:00
Gustavo A. R. Silva
245f5ab5ce flow_dissector: Fix out-of-bounds warning in __skb_flow_bpf_to_target()
[ Upstream commit 1e3d976dbb23b3fce544752b434bdc32ce64aabc ]

Fix the following out-of-bounds warning:

net/core/flow_dissector.c:835:3: warning: 'memcpy' offset [33, 48] from the object at 'flow_keys' is out of the bounds of referenced subobject 'ipv6_src' with type '__u32[4]' {aka 'unsigned int[4]'} at offset 16 [-Warray-bounds]

The problem is that the original code is trying to copy data into a
couple of struct members adjacent to each other in a single call to
memcpy().  So, the compiler legitimately complains about it. As these
are just a couple of members, fix this by copying each one of them in
separate calls to memcpy().

This helps with the ongoing efforts to globally enable -Warray-bounds
and get us closer to being able to tighten the FORTIFY_SOURCE routines
on memcpy().

Link: https://github.com/KSPP/linux/issues/109
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-19 10:12:57 +02:00
Alexander Lobakin
da54cc2549 gro: fix napi_gro_frags() Fast GRO breakage due to IP alignment check
[ Upstream commit 7ad18ff6449cbd6beb26b53128ddf56d2685aa93 ]

Commit 38ec4944b593 ("gro: ensure frag0 meets IP header alignment")
did the right thing, but missed the fact that napi_gro_frags() logics
calls for skb_gro_reset_offset() *before* pulling Ethernet header
to the skb linear space.
That said, the introduced check for frag0 address being aligned to 4
always fails for it as Ethernet header is obviously 14 bytes long,
and in case with NET_IP_ALIGN its start is not aligned to 4.

Fix this by adding @nhoff argument to skb_gro_reset_offset() which
tells if an IP header is placed right at the start of frag0 or not.
This restores Fast GRO for napi_gro_frags() that became very slow
after the mentioned commit, and preserves the introduced check to
avoid silent unaligned accesses.

From v1 [0]:
 - inline tiny skb_gro_reset_offset() to let the code be optimized
   more efficively (esp. for the !NET_IP_ALIGN case) (Eric);
 - pull in Reviewed-by from Eric.

[0] https://lore.kernel.org/netdev/20210418114200.5839-1-alobakin@pm.me

Fixes: 38ec4944b593 ("gro: ensure frag0 meets IP header alignment")
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-14 09:50:40 +02:00
Eric Dumazet
9143158a6b gro: ensure frag0 meets IP header alignment
commit 38ec4944b593fd90c5ef42aaaa53e66ae5769d04 upstream.

After commit 0f6925b3e8da ("virtio_net: Do not pull payload in skb->head")
Guenter Roeck reported one failure in his tests using sh architecture.

After much debugging, we have been able to spot silent unaligned accesses
in inet_gro_receive()

The issue at hand is that upper networking stacks assume their header
is word-aligned. Low level drivers are supposed to reserve NET_IP_ALIGN
bytes before the Ethernet header to make that happen.

This patch hardens skb_gro_reset_offset() to not allow frag0 fast-path
if the fragment is not properly aligned.

Some arches like x86, arm64 and powerpc do not care and define NET_IP_ALIGN
as 0, this extra check will be a NOP for them.

Note that if frag0 is not used, GRO will call pskb_may_pull()
as many times as needed to pull network and transport headers.

Fixes: 0f6925b3e8da ("virtio_net: Do not pull payload in skb->head")
Fixes: 78a478d0efd9 ("gro: Inline skb_gro_header and cache frag0 virtual address")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-21 13:00:58 +02:00
Tong Zhu
0d0ad98bee neighbour: Disregard DEAD dst in neigh_update
[ Upstream commit d47ec7a0a7271dda08932d6208e4ab65ab0c987c ]

After a short network outage, the dst_entry is timed out and put
in DST_OBSOLETE_DEAD. We are in this code because arp reply comes
from this neighbour after network recovers. There is a potential
race condition that dst_entry is still in DST_OBSOLETE_DEAD.
With that, another neighbour lookup causes more harm than good.

In best case all packets in arp_queue are lost. This is
counterproductive to the original goal of finding a better path
for those packets.

I observed a worst case with 4.x kernel where a dst_entry in
DST_OBSOLETE_DEAD state is associated with loopback net_device.
It leads to an ethernet header with all zero addresses.
A packet with all zero source MAC address is quite deadly with
mac80211, ath9k and 802.11 block ack.  It fails
ieee80211_find_sta_by_ifaddr in ath9k (xmit.c). Ath9k flushes tx
queue (ath_tx_complete_aggr). BAW (block ack window) is not
updated. BAW logic is damaged and ath9k transmission is disabled.

Signed-off-by: Tong Zhu <zhutong@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-21 13:00:52 +02:00
Ong Boon Leong
553290002a xdp: fix xdp_return_frame() kernel BUG throw for page_pool memory model
[ Upstream commit 622d13694b5f048c01caa7ba548498d9880d4cb0 ]

xdp_return_frame() may be called outside of NAPI context to return
xdpf back to page_pool. xdp_return_frame() calls __xdp_return() with
napi_direct = false. For page_pool memory model, __xdp_return() calls
xdp_return_frame_no_direct() unconditionally and below false negative
kernel BUG throw happened under preempt-rt build:

[  430.450355] BUG: using smp_processor_id() in preemptible [00000000] code: modprobe/3884
[  430.451678] caller is __xdp_return+0x1ff/0x2e0
[  430.452111] CPU: 0 PID: 3884 Comm: modprobe Tainted: G     U      E     5.12.0-rc2+ #45

Changes in v2:
 - This patch fixes the issue by making xdp_return_frame_no_direct() is
   only called if napi_direct = true, as recommended for better by
   Jesper Dangaard Brouer. Thanks!

Fixes: 2539650fadbf ("xdp: Helpers for disabling napi_direct of xdp_return_frame")
Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-14 08:42:09 +02:00
Paolo Abeni
b830650c1a net: let skb_orphan_partial wake-up waiters.
commit 9adc89af724f12a03b47099cd943ed54e877cd59 upstream.

Currently the mentioned helper can end-up freeing the socket wmem
without waking-up any processes waiting for more write memory.

If the partially orphaned skb is attached to an UDP (or raw) socket,
the lack of wake-up can hang the user-space.

Even for TCP sockets not calling the sk destructor could have bad
effects on TSQ.

Address the issue using skb_orphan to release the sk wmem before
setting the new sock_efree destructor. Additionally bundle the
whole ownership update in a new helper, so that later other
potential users could avoid duplicate code.

v1 -> v2:
 - use skb_orphan() instead of sort of open coding it (Eric)
 - provide an helper for the ownership change (Eric)

Fixes: f6ba8d33cfbb ("netem: fix skb_orphan_partial()")
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14 08:42:03 +02:00
John Fastabend
72c5de25ba bpf, sockmap: Fix incorrect fwd_alloc accounting
commit 144748eb0c445091466c9b741ebd0bfcc5914f3d upstream.

Incorrect accounting fwd_alloc can result in a warning when the socket
is torn down,

 [18455.319240] WARNING: CPU: 0 PID: 24075 at net/core/stream.c:208 sk_stream_kill_queues+0x21f/0x230
 [...]
 [18455.319543] Call Trace:
 [18455.319556]  inet_csk_destroy_sock+0xba/0x1f0
 [18455.319577]  tcp_rcv_state_process+0x1b4e/0x2380
 [18455.319593]  ? lock_downgrade+0x3a0/0x3a0
 [18455.319617]  ? tcp_finish_connect+0x1e0/0x1e0
 [18455.319631]  ? sk_reset_timer+0x15/0x70
 [18455.319646]  ? tcp_schedule_loss_probe+0x1b2/0x240
 [18455.319663]  ? lock_release+0xb2/0x3f0
 [18455.319676]  ? __release_sock+0x8a/0x1b0
 [18455.319690]  ? lock_downgrade+0x3a0/0x3a0
 [18455.319704]  ? lock_release+0x3f0/0x3f0
 [18455.319717]  ? __tcp_close+0x2c6/0x790
 [18455.319736]  ? tcp_v4_do_rcv+0x168/0x370
 [18455.319750]  tcp_v4_do_rcv+0x168/0x370
 [18455.319767]  __release_sock+0xbc/0x1b0
 [18455.319785]  __tcp_close+0x2ee/0x790
 [18455.319805]  tcp_close+0x20/0x80

This currently happens because on redirect case we do skb_set_owner_r()
with the original sock. This increments the fwd_alloc memory accounting
on the original sock. Then on redirect we may push this into the queue
of the psock we are redirecting to. When the skb is flushed from the
queue we give the memory back to the original sock. The problem is if
the original sock is destroyed/closed with skbs on another psocks queue
then the original sock will not have a way to reclaim the memory before
being destroyed. Then above warning will be thrown

  sockA                          sockB

  sk_psock_strp_read()
   sk_psock_verdict_apply()
     -- SK_REDIRECT --
     sk_psock_skb_redirect()
                                skb_queue_tail(psock_other->ingress_skb..)

  sk_close()
   sock_map_unref()
     sk_psock_put()
       sk_psock_drop()
         sk_psock_zap_ingress()

At this point we have torn down our own psock, but have the outstanding
skb in psock_other. Note that SK_PASS doesn't have this problem because
the sk_psock_drop() logic releases the skb, its still associated with
our psock.

To resolve lets only account for sockets on the ingress queue that are
still associated with the current socket. On the redirect case we will
check memory limits per 6fa9201a89898, but will omit fwd_alloc accounting
until skb is actually enqueued. When the skb is sent via skb_send_sock_locked
or received with sk_psock_skb_ingress memory will be claimed on psock_other.

Fixes: 6fa9201a89898 ("bpf, sockmap: Avoid returning unneeded EAGAIN when redirecting to self")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/161731444013.68884.4021114312848535993.stgit@john-XPS-13-9370
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14 08:42:01 +02:00
Jesper Dangaard Brouer
fd38d4e675 bpf: Remove MTU check in __bpf_skb_max_len
commit 6306c1189e77a513bf02720450bb43bd4ba5d8ae upstream.

Multiple BPF-helpers that can manipulate/increase the size of the SKB uses
__bpf_skb_max_len() as the max-length. This function limit size against
the current net_device MTU (skb->dev->mtu).

When a BPF-prog grow the packet size, then it should not be limited to the
MTU. The MTU is a transmit limitation, and software receiving this packet
should be allowed to increase the size. Further more, current MTU check in
__bpf_skb_max_len uses the MTU from ingress/current net_device, which in
case of redirects uses the wrong net_device.

This patch keeps a sanity max limit of SKB_MAX_ALLOC (16KiB). The real limit
is elsewhere in the system. Jesper's testing[1] showed it was not possible
to exceed 8KiB when expanding the SKB size via BPF-helper. The limiting
factor is the define KMALLOC_MAX_CACHE_SIZE which is 8192 for
SLUB-allocator (CONFIG_SLUB) in-case PAGE_SIZE is 4096. This define is
in-effect due to this being called from softirq context see code
__gfp_pfmemalloc_flags() and __do_kmalloc_node(). Jakub's testing showed
that frames above 16KiB can cause NICs to reset (but not crash). Keep this
sanity limit at this level as memory layer can differ based on kernel
config.

[1] https://github.com/xdp-project/bpf-examples/tree/master/MTU-tests

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/161287788936.790810.2937823995775097177.stgit@firesoul
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-07 15:00:08 +02:00