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commit 76b39b94382f9e0a639e1c70c3253de248cc4c83 upstream.
If during an action flush operation one of the actions is still being
referenced, the flush operation is aborted and the kernel returns to
user space with an error. However, if the kernel was able to flush, for
example, 3 actions and failed on the fourth, the kernel will not notify
user space that it deleted 3 actions before failing.
This patch fixes that behaviour by notifying user space of how many
actions were deleted before flush failed and by setting extack with a
message describing what happened.
Fixes: 55334a5db5cd ("net_sched: act: refuse to remove bound action outside")
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a2b1a5d40bd12b44322c2ccd40bb0ec1699708b6 ]
As reported by Yuming, currently tc always show a latency of UINT_MAX
for netem Qdisc's on 32-bit platforms:
$ tc qdisc add dev dummy0 root netem latency 100ms
$ tc qdisc show dev dummy0
qdisc netem 8001: root refcnt 2 limit 1000 delay 275s 275s
^^^^^^^^^^^^^^^^
Let us take a closer look at netem_dump():
qopt.latency = min_t(psched_tdiff_t, PSCHED_NS2TICKS(q->latency,
UINT_MAX);
qopt.latency is __u32, psched_tdiff_t is signed long,
(psched_tdiff_t)(UINT_MAX) is negative for 32-bit platforms, so
qopt.latency is always UINT_MAX.
Fix it by using psched_time_t (u64) instead.
Note: confusingly, users have two ways to specify 'latency':
1. normally, via '__u32 latency' in struct tc_netem_qopt;
2. via the TCA_NETEM_LATENCY64 attribute, which is s64.
For the second case, theoretically 'latency' could be negative. This
patch ignores that corner case, since it is broken (i.e. assigning a
negative s64 to __u32) anyways, and should be handled separately.
Thanks Ted Lin for the analysis [1] .
[1] https://github.com/raspberrypi/linux/issues/3512
Reported-by: Yuming Chen <chenyuming.junnan@bytedance.com>
Fixes: 112f9cb65643 ("netem: convert to qdisc_watchdog_schedule_ns")
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Link: https://lore.kernel.org/r/20220616234336.2443-1-yepeilin.cs@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 4ddc844eb81da59bfb816d8d52089aba4e59e269 upstream.
in current Linux, MTU policing does not take into account that packets at
the TC ingress have the L2 header pulled. Thus, the same TC police action
(with the same value of tcfp_mtu) behaves differently for ingress/egress.
In addition, the full GSO size is compared to tcfp_mtu: as a consequence,
the policer drops GSO packets even when individual segments have the L2 +
L3 + L4 + payload length below the configured valued of tcfp_mtu.
Improve the accuracy of MTU policing as follows:
- account for mac_len for non-GSO packets at TC ingress.
- compare MTU threshold with the segmented size for GSO packets.
Also, add a kselftest that verifies the correct behavior.
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[dcaratti: fix conflicts due to lack of the following commits:
- commit 2ffe0395288a ("net/sched: act_police: add support for
packet-per-second policing")
- commit afe231d32eb5 ("selftests: forwarding: Add tc-police tests")
- commit 53b61f29367d ("selftests: forwarding: Add tc-police tests for
packets per second")]
Link: https://lore.kernel.org/netdev/876d597a0ff55f6ba786f73c5a9fd9eb8d597a03.1644514748.git.dcaratti@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 4d42d54a7d6aa6d29221d3fd4f2ae9503e94f011 ]
syzbot was able to trigger an Out-of-Bound on the pedit action:
UBSAN: shift-out-of-bounds in net/sched/act_pedit.c:238:43
shift exponent 1400735974 is too large for 32-bit type 'unsigned int'
CPU: 0 PID: 3606 Comm: syz-executor151 Not tainted 5.18.0-rc5-syzkaller-00165-g810c2f0a3f86 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
ubsan_epilogue+0xb/0x50 lib/ubsan.c:151
__ubsan_handle_shift_out_of_bounds.cold+0xb1/0x187 lib/ubsan.c:322
tcf_pedit_init.cold+0x1a/0x1f net/sched/act_pedit.c:238
tcf_action_init_1+0x414/0x690 net/sched/act_api.c:1367
tcf_action_init+0x530/0x8d0 net/sched/act_api.c:1432
tcf_action_add+0xf9/0x480 net/sched/act_api.c:1956
tc_ctl_action+0x346/0x470 net/sched/act_api.c:2015
rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5993
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:705 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:725
____sys_sendmsg+0x6e2/0x800 net/socket.c:2413
___sys_sendmsg+0xf3/0x170 net/socket.c:2467
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2496
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fe36e9e1b59
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffef796fe88 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe36e9e1b59
RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000003
RBP: 00007fe36e9a5d00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe36e9a5d90
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
The 'shift' field is not validated, and any value above 31 will
trigger out-of-bounds. The issue predates the git history, but
syzbot was able to trigger it only after the commit mentioned in
the fixes tag, and this change only applies on top of such commit.
Address the issue bounding the 'shift' value to the maximum allowed
by the relevant operator.
Reported-and-tested-by: syzbot+8ed8fc4c57e9dcf23ca6@syzkaller.appspotmail.com
Fixes: 8b796475fd78 ("net/sched: act_pedit: really ensure the skb is writable")
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>
[ Upstream commit 8b796475fd7882663a870456466a4fb315cc1bd6 ]
Currently pedit tries to ensure that the accessed skb offset
is writable via skb_unclone(). The action potentially allows
touching any skb bytes, so it may end-up modifying shared data.
The above causes some sporadic MPTCP self-test failures, due to
this code:
tc -n $ns2 filter add dev ns2eth$i egress \
protocol ip prio 1000 \
handle 42 fw \
action pedit munge offset 148 u8 invert \
pipe csum tcp \
index 100
The above modifies a data byte outside the skb head and the skb is
a cloned one, carrying a TCP output packet.
This change addresses the issue by keeping track of a rough
over-estimate highest skb offset accessed by the action and ensuring
such offset is really writable.
Note that this may cause performance regressions in some scenarios,
but hopefully pedit is not in the critical path.
Fixes: db2c24175d14 ("act_pedit: access skb->data safely")
Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Tested-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/1fcf78e6679d0a287dd61bb0f04730ce33b3255d.1652194627.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ec5b0f605b105457f257f2870acad4a5d463984b ]
While investigating a related syzbot report,
I found that whenever call to tcf_exts_init()
from u32_init_knode() is failing, we end up
with an elevated refcount on ht->refcnt
To avoid that, only increase the refcount after
all possible errors have been evaluated.
Fixes: b9a24bb76bf6 ("net_sched: properly handle failure case of tcf_exts_init()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e8a64bbaaad1f6548cec5508297bc6d45e8ab69e ]
A user may set the SO_TXTIME socket option to ensure a packet is send
at a given time. The taprio scheduler has to confirm, that it is allowed
to send a packet at that given time, by a check against the packet time
schedule. The scheduler drop the packet, if the gates are closed at the
given send time.
The check, if SO_TXTIME is set, may fail since sk_flags are part of an
union and the union is used otherwise. This happen, if a socket is not
a full socket, like a request socket for example.
Add a check to verify, if the union is used for sk_flags.
Fixes: 4cfd5779bd6e ("taprio: Add support for txtime-assist mode")
Signed-off-by: Benedikt Spranger <b.spranger@linutronix.de>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e65812fd22eba32f11abe28cb377cbd64cfb1ba0 ]
Currently, when inserting a new filter that needs to sit at the head
of chain 0, it will first update the heads pointer on all devices using
the (shared) block, and only then complete the initialization of the new
element so that it has a "next" element.
This can lead to a situation that the chain 0 head is propagated to
another CPU before the "next" initialization is done. When this race
condition is triggered, packets being matched on that CPU will simply
miss all other filters, and will flow through the stack as if there were
no other filters installed. If the system is using OVS + TC, such
packets will get handled by vswitchd via upcall, which results in much
higher latency and reordering. For other applications it may result in
packet drops.
This is reproducible with a tc only setup, but it varies from system to
system. It could be reproduced with a shared block amongst 10 veth
tunnels, and an ingress filter mirroring packets to another veth.
That's because using the last added veth tunnel to the shared block to
do the actual traffic, it makes the race window bigger and easier to
trigger.
The fix is rather simple, to just initialize the next pointer of the new
filter instance (tp) before propagating the head change.
The fixes tag is pointing to the original code though this issue should
only be observed when using it unlocked.
Fixes: 2190d1d0944f ("net: sched: introduce helpers to work with filter chains")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/r/b97d5f4eaffeeb9d058155bcab63347527261abf.1649341369.git.marcelo.leitner@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2105f700b53c24aa48b65c15652acc386044d26a ]
A tc flower filter matching TCA_FLOWER_KEY_VLAN_ETH_TYPE is expected to
match the L2 ethertype following the first VLAN header, as confirmed by
linked discussion with the maintainer. However, such rule also matches
packets that have additional second VLAN header, even though filter has
both eth_type and vlan_ethtype set to "ipv4". Looking at the code this
seems to be mostly an artifact of the way flower uses flow dissector.
First, even though looking at the uAPI eth_type and vlan_ethtype appear
like a distinct fields, in flower they are all mapped to the same
key->basic.n_proto. Second, flow dissector skips following VLAN header as
no keys for FLOW_DISSECTOR_KEY_CVLAN are set and eventually assigns the
value of n_proto to last parsed header. With these, such filters ignore any
headers present between first VLAN header and first "non magic"
header (ipv4 in this case) that doesn't result
FLOW_DISSECT_RET_PROTO_AGAIN.
Fix the issue by extending flow dissector VLAN key structure with new
'vlan_eth_type' field that matches first ethertype following previously
parsed VLAN header. Modify flower classifier to set the new
flow_dissector_key_vlan->vlan_eth_type with value obtained from
TCA_FLOWER_KEY_VLAN_ETH_TYPE/TCA_FLOWER_KEY_CVLAN_ETH_TYPE uAPIs.
Link: https://lore.kernel.org/all/Yjhgi48BpTGh6dig@nanopsycho/
Fixes: 9399ae9a6cb2 ("net_sched: flower: Add vlan support")
Fixes: d64efd0926ba ("net/sched: flower: Add supprt for matching on QinQ vlan headers")
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 973bf8fdd12f0e70ea351c018e68edd377a836d1 ]
When adding a tc rule with a qdisc kind that is not supported or not
compiled into the kernel, the kernel emits the following error: "Error:
Specified qdisc not found.". Found via tdc testing when ETS qdisc was not
compiled in and it was not obvious right away what the message meant
without looking at the kernel code.
Change the error message to be more explicit and say the qdisc kind is
unknown.
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit fb80445c438c78b40b547d12b8d56596ce4ccfeb upstream.
commit 56b765b79e9a ("htb: improved accuracy at high rates") broke
"overhead X", "linklayer atm" and "mpu X" attributes.
"overhead X" and "linklayer atm" have already been fixed. This restores
the "mpu X" handling, as might be used by DOCSIS or Ethernet shaping:
tc class add ... htb rate X overhead 4 mpu 64
The code being fixed is used by htb, tbf and act_police. Cake has its
own mpu handling. qdisc_calculate_pkt_len still uses the size table
containing values adjusted for mpu by user space.
iproute2 tc has always passed mpu into the kernel via a tc_ratespec
structure, but the kernel never directly acted on it, merely stored it
so that it could be read back by `tc class show`.
Rather, tc would generate length-to-time tables that included the mpu
(and linklayer) in their construction, and the kernel used those tables.
Since v3.7, the tables were no longer used. Along with "mpu", this also
broke "overhead" and "linklayer" which were fixed in 01cb71d2d47b
("net_sched: restore "overhead xxx" handling", v3.10) and 8a8e3d84b171
("net_sched: restore "linklayer atm" handling", v3.11).
"overhead" was fixed by simply restoring use of tc_ratespec::overhead -
this had originally been used by the kernel but was initially omitted
from the new non-table-based calculations.
"linklayer" had been handled in the table like "mpu", but the mode was
not originally passed in tc_ratespec. The new implementation was made to
handle it by getting new versions of tc to pass the mode in an extended
tc_ratespec, and for older versions of tc the table contents were analysed
at load time to deduce linklayer.
As "mpu" has always been given to the kernel in tc_ratespec,
accompanying the mpu-based table, we can restore system functionality
with no userspace change by making the kernel act on the tc_ratespec
value.
Fixes: 56b765b79e9a ("htb: improved accuracy at high rates")
Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: Vimalkumar <j.vimal@gmail.com>
Link: https://lore.kernel.org/r/20220112170210.1014351-1-kevin@bracey.fi
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7d18a07897d07495ee140dd319b0e9265c0f68ba upstream.
tx_queue_len can be set to ~0U, we need to be more
careful about overflows.
__fls(0) is undefined, as this report shows:
UBSAN: shift-out-of-bounds in net/sched/sch_qfq.c:1430:24
shift exponent 51770272 is too large for 32-bit type 'int'
CPU: 0 PID: 25574 Comm: syz-executor.0 Not tainted 5.16.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x201/0x2d8 lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:151 [inline]
__ubsan_handle_shift_out_of_bounds+0x494/0x530 lib/ubsan.c:330
qfq_init_qdisc+0x43f/0x450 net/sched/sch_qfq.c:1430
qdisc_create+0x895/0x1430 net/sched/sch_api.c:1253
tc_modify_qdisc+0x9d9/0x1e20 net/sched/sch_api.c:1660
rtnetlink_rcv_msg+0x934/0xe60 net/core/rtnetlink.c:5571
netlink_rcv_skb+0x200/0x470 net/netlink/af_netlink.c:2496
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x814/0x9f0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0xaea/0xe60 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg net/socket.c:724 [inline]
____sys_sendmsg+0x5b9/0x910 net/socket.c:2409
___sys_sendmsg net/socket.c:2463 [inline]
__sys_sendmsg+0x280/0x370 net/socket.c:2492
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Fixes: 462dbc9101ac ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost")
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 166b6a46b78bf8b9559a6620c3032f9fe492e082 ]
We need to return EOPNOTSUPP for the unsupported mpls action type when
setup the flow action.
In the original implement, we will return 0 for the unsupported mpls
action type, actually we do not setup it and the following actions
to the flow action entry.
Fixes: 9838b20a7fb2 ("net: sched: take rtnl lock in tc_setup_flow_action()")
Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7a47281439ba00b11fc098f36695522184ce5a82 ]
In order to remove dependency on rtnl lock, take action's tcfa_lock when
constructing its representation as flow_action_entry structure.
Refactor tcf_sample_get_group() to assume that caller holds tcf_lock and
don't take it manually. This callback is only called from flow_action infra
representation translator which now calls it with tcf_lock held, so this
refactoring is necessary to prevent deadlock.
Allocate memory with GFP_ATOMIC flag for ip_tunnel_info copy because
tcf_tunnel_info_copy() is only called from flow_action representation infra
code with tcf_lock spinlock taken.
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f799ada6bf2397c351220088b9b0980125c77280 ]
Without dropping dst, the packets sent from local mirred/redirected
to ingress will may still use the old dst. ip_rcv() will drop it as
the old dst is for output and its .input is dst_discard.
This patch is to fix by also dropping dst for those packets that are
mirred or redirected from egress to ingress in act_mirred.
Note that we don't drop it for the direction change from ingress to
egress, as on which there might be a user case attaching a metadata
dst by act_tunnel_key that would be used later.
Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Cong Wang <cong.wang@bytedance.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ 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>
commit 14132690860e4d06aa3e1c4d7d8e9866ba7756dd upstream.
Introduction of lockless subqueues broke the class statistics.
Before the change stats were accumulated in `bstats' and `qstats'
on the stack which was then copied to struct gnet_dump.
After the change the `bstats' and `qstats' are initialized to 0
and never updated, yet still fed to gnet_dump. The code updates
the global qdisc->cpu_bstats and qdisc->cpu_qstats instead,
clobbering them. Most likely a copy-paste error from the code in
mqprio_dump().
__gnet_stats_copy_basic() and __gnet_stats_copy_queue() accumulate
the values for per-CPU case but for global stats they overwrite
the value, so only stats from the last loop iteration / tc end up
in sch->[bq]stats.
Use the on-stack [bq]stats variables again and add the stats manually
in the global case.
Fixes: ce679e8df7ed2 ("net: sched: add support for TCQ_F_NOLOCK subqueues to sch_mqprio")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
https://lore.kernel.org/all/20211007175000.2334713-2-bigeasy@linutronix.de/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b193e15ac69d56f35e1d8e2b5d16cbd47764d053 ]
We observed below report when playing with netlink sock:
UBSAN: shift-out-of-bounds in net/sched/sch_api.c:580:10
shift exponent 249 is too large for 32-bit type
CPU: 0 PID: 685 Comm: a.out Not tainted
Call Trace:
dump_stack_lvl+0x8d/0xcf
ubsan_epilogue+0xa/0x4e
__ubsan_handle_shift_out_of_bounds+0x161/0x182
__qdisc_calculate_pkt_len+0xf0/0x190
__dev_queue_xmit+0x2ed/0x15b0
it seems like kernel won't check the stab log value passing from
user, and will use the insane value later to calculate pkt_len.
This patch just add a check on the size/cell_log to avoid insane
calculation.
Reported-by: Abaci <abaci@linux.alibaba.com>
Signed-off-by: Michael Wang <yun.wang@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c7c5e6ff533fe1f9afef7d2fa46678987a1335a7 ]
syzbot found that forcing a big quantum attribute would crash hosts fast,
essentially using this:
tc qd replace dev eth0 root fq_codel quantum 4294967295
This is because fq_codel_dequeue() would have to loop
~2^31 times in :
if (flow->deficit <= 0) {
flow->deficit += q->quantum;
list_move_tail(&flow->flowchain, &q->old_flows);
goto begin;
}
SFQ max quantum is 2^19 (half a megabyte)
Lets adopt a max quantum of one megabyte for FQ_CODEL.
Fixes: 4b549a2ef4be ("fq_codel: Fair Queue Codel AQM")
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>
[ Upstream commit efe487fce3061d94222c6501d7be3aa549b3dc78 ]
syzbot report an array-index-out-of-bounds in taprio_change
index 16 is out of range for type '__u16 [16]'
that's because mqprio->num_tc is lager than TC_MAX_QUEUE,so we check
the return value of netdev_set_num_tc.
Reported-by: syzbot+2b3e5fb6c7ef285a94f6@syzkaller.appspotmail.com
Signed-off-by: Haimin Zhang <tcs_kernel@tencent.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c66070125837900163b81a03063ddd657a7e9bfb ]
The reference counting issue happens in one exception handling path of
cbq_change_class(). When failing to get tcf_block, the function forgets
to decrease the refcount of "rtab" increased by qdisc_put_rtab(),
causing a refcount leak.
Fix this issue by jumping to "failure" label when get tcf_block failed.
Fixes: 6529eaba33f0 ("net: sched: introduce tcf block infractructure")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Link: https://lore.kernel.org/r/1630252681-71588-1-git-send-email-xiyuyang19@fudan.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d09c548dbf3b31cb07bba562e0f452edfa01efe3 ]
When mirror/redirect a skb to a different port, the ct info should be reset
for reclassification. Or the pkts will match unexpected rules. For example,
with following topology and commands:
-----------
|
veth0 -+-------
|
veth1 -+-------
|
------------
tc qdisc add dev veth0 clsact
# The same with "action mirred egress mirror dev veth1" or "action mirred ingress redirect dev veth1"
tc filter add dev veth0 egress chain 1 protocol ip flower ct_state +trk action mirred ingress mirror dev veth1
tc filter add dev veth0 egress chain 0 protocol ip flower ct_state -inv action ct commit action goto chain 1
tc qdisc add dev veth1 clsact
tc filter add dev veth1 ingress chain 0 protocol ip flower ct_state +trk action drop
ping <remove ip via veth0> &
tc -s filter show dev veth1 ingress
With command 'tc -s filter show', we can find the pkts were dropped on
veth1.
Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct")
Signed-off-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 580e4273d7a883ececfefa692c1f96bdbacb99b5 ]
Although we take RTNL on dump path, it is possible to
skip RTNL on insertion path. So the following race condition
is possible:
rtnl_lock() // no rtnl lock
mutex_lock(&idrinfo->lock);
// insert ERR_PTR(-EBUSY)
mutex_unlock(&idrinfo->lock);
tc_dump_action()
rtnl_unlock()
So we have to skip those temporary -EBUSY entries on dump path
too.
Reported-and-tested-by: syzbot+b47bc4f247856fb4d9e1@syzkaller.appspotmail.com
Fixes: 0fedc63fadf0 ("net_sched: commit action insertions together")
Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9d85a6f44bd5585761947f40f7821c9cd78a1bbe ]
The 4th parameter in tc_chain_notify() should be flags rather than seq.
Let's change it back correctly.
Fixes: 32a4f5ecd738 ("net: sched: introduce chain object to uapi")
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>
[ Upstream commit 727d6a8b7ef3d25080fad228b2c4a1d4da5999c6 ]
Currently tcf_skbmod_act() assumes that packets use Ethernet as their L2
protocol, which is not always the case. As an example, for CAN devices:
$ ip link add dev vcan0 type vcan
$ ip link set up vcan0
$ tc qdisc add dev vcan0 root handle 1: htb
$ tc filter add dev vcan0 parent 1: protocol ip prio 10 \
matchall action skbmod swap mac
Doing the above silently corrupts all the packets. Do not perform skbmod
actions for non-Ethernet packets.
Fixes: 86da71b57383 ("net_sched: Introduce skbmod action")
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f5051bcece50140abd1a11a2d36dc3ec5484fc32 ]
Syzbot reported memory leak in tcindex_set_parms(). The problem was in
non-freed perfect hash in tcindex_partial_destroy_work().
In tcindex_set_parms() new tcindex_data is allocated and some fields from
old one are copied to new one, but not the perfect hash. Since
tcindex_partial_destroy_work() is the destroy function for old
tcindex_data, we need to free perfect hash to avoid memory leak.
Reported-and-tested-by: syzbot+f0bbb2287b8993d4fa74@syzkaller.appspotmail.com
Fixes: 331b72922c5f ("net: sched: RCU cls_tcindex")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8955b90c3cdad199137809aac8ccbbb585355913 upstream.
The confirm operation should be checked. If there are any failed,
the packet should be dropped like in ovs and netfilter.
Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct")
Signed-off-by: wenxu <wenxu@ucloud.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 55d96f72e8ddc0a294e0b9c94016edbb699537e1 ]
When nla_put_u32() fails, 'ret' could be 0, it should
return error code in tcf_del_walker().
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3f2db250099f46988088800052cdf2332c7aba61 ]
Syzbot reported warning in tcindex_alloc_perfect_hash. The problem
was in too big cp->hash, which triggers warning in kmalloc. Since
cp->hash comes from userspace, there is no need to warn if value
is not correct
Fixes: b9a24bb76bf6 ("net_sched: properly handle failure case of tcf_exts_init()")
Reported-and-tested-by: syzbot+1071ad60cd7df39fdadb@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Acked-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9c5eee0afca09cbde6bd00f77876754aaa552970 ]
Currently vlan modification action checks existence of vlan priority by
comparing it to 0. Therefore it is impossible to modify existing vlan
tag to have priority 0.
For example, the following tc command will change the vlan id but will
not affect vlan priority:
tc filter add dev eth1 ingress matchall action vlan modify id 300 \
priority 0 pipe mirred egress redirect dev eth2
The incoming packet on eth1:
ethertype 802.1Q (0x8100), vlan 200, p 4, ethertype IPv4
will be changed to:
ethertype 802.1Q (0x8100), vlan 300, p 4, ethertype IPv4
although the user has intended to have p == 0.
The fix is to add tcfv_push_prio_exists flag to struct tcf_vlan_params
and rely on it when deciding to set the priority.
Fixes: 45a497f2d149a4a8061c (net/sched: act_vlan: Introduce TCA_VLAN_ACT_MODIFY vlan action)
Signed-off-by: Boris Sukholitko <boris.sukholitko@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ba91c49dedbde758ba0b72f57ac90b06ddf8e548 ]
The TCP option parser in cake qdisc (cake_get_tcpopt and
cake_tcph_may_drop) could read one byte out of bounds. When the length
is 1, the execution flow gets into the loop, reads one byte of the
opcode, and if the opcode is neither TCPOPT_EOL nor TCPOPT_NOP, it reads
one more byte, which exceeds the length of 1.
This fix is inspired by commit 9609dad263f8 ("ipv4: tcp_input: fix stack
out of bounds when parsing TCP options.").
v2 changes:
Added doff validation in cake_get_tcphdr to avoid parsing garbage as TCP
header. Although it wasn't strictly an out-of-bounds access (memory was
allocated), garbage values could be read where CAKE expected the TCP
header if doff was smaller than 5.
Cc: Young Xiao <92siuyang@gmail.com>
Fixes: 8b7138814f29 ("sch_cake: Add optional ACK filter")
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 13c62f5371e3eb4fc3400cfa26e64ca75f888008 ]
This this the counterpart of 8aa7b526dc0b ("openvswitch: handle DNAT
tuple collision") for act_ct. From that commit changelog:
"""
With multiple DNAT rules it's possible that after destination
translation the resulting tuples collide.
...
Netfilter handles this case by allocating a null binding for SNAT at
egress by default. Perform the same operation in openvswitch for DNAT
if no explicit SNAT is requested by the user and allocate a null binding
for SNAT for packets in the "original" direction.
"""
Fixes: 95219afbb980 ("act_ct: support asymmetric conntrack")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fb91702b743dec78d6507c53a2dec8a8883f509d ]
Fix current behavior of skipping template allocation in case the
ct action is in zone 0.
Skipping the allocation may cause the datapath ct code to ignore the
entire ct action with all its attributes (commit, nat) in case the ct
action in zone 0 was preceded by a ct clear action.
The ct clear action sets the ct_state to untracked and resets the
skb->_nfct pointer. Under these conditions and without an allocated
ct template, the skb->_nfct pointer will remain NULL which will
cause the tc ct action handler to exit without handling commit and nat
actions, if such exist.
For example, the following rule in OVS dp:
recirc_id(0x2),ct_state(+new-est-rel-rpl+trk),ct_label(0/0x1), \
in_port(eth0),actions:ct_clear,ct(commit,nat(src=10.11.0.12)), \
recirc(0x37a)
Will result in act_ct skipping the commit and nat actions in zone 0.
The change removes the skipping of template allocation for zone 0 and
treats it the same as any other zone.
Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct")
Signed-off-by: Ariel Levkovich <lariel@nvidia.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Link: https://lore.kernel.org/r/20210526170110.54864-1-lariel@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ 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>
[ 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>
[ Upstream commit a90c57f2cedd52a511f739fb55e6244e22e1a2fb ]
Lockless qdisc has below concurrent problem:
cpu0 cpu1
. .
q->enqueue .
. .
qdisc_run_begin() .
. .
dequeue_skb() .
. .
sch_direct_xmit() .
. .
. q->enqueue
. qdisc_run_begin()
. return and do nothing
. .
qdisc_run_end() .
cpu1 enqueue a skb without calling __qdisc_run() because cpu0
has not released the lock yet and spin_trylock() return false
for cpu1 in qdisc_run_begin(), and cpu0 do not see the skb
enqueued by cpu1 when calling dequeue_skb() because cpu1 may
enqueue the skb after cpu0 calling dequeue_skb() and before
cpu0 calling qdisc_run_end().
Lockless qdisc has below another concurrent problem when
tx_action is involved:
cpu0(serving tx_action) cpu1 cpu2
. . .
. q->enqueue .
. qdisc_run_begin() .
. dequeue_skb() .
. . q->enqueue
. . .
. sch_direct_xmit() .
. . qdisc_run_begin()
. . return and do nothing
. . .
clear __QDISC_STATE_SCHED . .
qdisc_run_begin() . .
return and do nothing . .
. . .
. qdisc_run_end() .
This patch fixes the above data race by:
1. If the first spin_trylock() return false and STATE_MISSED is
not set, set STATE_MISSED and retry another spin_trylock() in
case other CPU may not see STATE_MISSED after it releases the
lock.
2. reschedule if STATE_MISSED is set after the lock is released
at the end of qdisc_run_end().
For tx_action case, STATE_MISSED is also set when cpu1 is at the
end if qdisc_run_end(), so tx_action will be rescheduled again
to dequeue the skb enqueued by cpu2.
Clear STATE_MISSED before retrying a dequeuing when dequeuing
returns NULL in order to reduce the overhead of the second
spin_trylock() and __netif_schedule() calling.
Also clear the STATE_MISSED before calling __netif_schedule()
at the end of qdisc_run_end() to avoid doing another round of
dequeuing in the pfifo_fast_dequeue().
The performance impact of this patch, tested using pktgen and
dummy netdev with pfifo_fast qdisc attached:
threads without+this_patch with+this_patch delta
1 2.61Mpps 2.60Mpps -0.3%
2 3.97Mpps 3.82Mpps -3.7%
4 5.62Mpps 5.59Mpps -0.5%
8 2.78Mpps 2.77Mpps -0.3%
16 2.22Mpps 2.22Mpps -0.0%
Fixes: 6b3ba9146fe6 ("net: sched: allow qdiscs to handle locking")
Acked-by: Jakub Kicinski <kuba@kernel.org>
Tested-by: Juergen Gross <jgross@suse.com>
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>
[ Upstream commit ed8157f1ebf1ae81a8fa2653e3f20d2076fad1c9 ]
There is a reproducible sequence from the userland that will trigger a WARN_ON()
condition in taprio_get_start_time, which causes kernel to panic if configured
as "panic_on_warn". Catch this condition in parse_taprio_schedule to
prevent this condition.
Reported as bug on syzkaller:
https://syzkaller.appspot.com/bug?extid=d50710fd0873a9c6b40c
Reported-by: syzbot+d50710fd0873a9c6b40c@syzkaller.appspotmail.com
Signed-off-by: Du Cheng <ducheng2@gmail.com>
Acked-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 6855e8213e06efcaf7c02a15e12b1ae64b9a7149 upstream.
Currently, action creation using ACT API in replace mode is buggy.
When invoking for non-existent action index 42,
tc action replace action bpf obj foo.o sec <xyz> index 42
kernel creates the action, fills up the netlink response, and then just
deletes the action after notifying userspace.
tc action show action bpf
doesn't list the action.
This happens due to the following sequence when ovr = 1 (replace mode)
is enabled:
tcf_idr_check_alloc is used to atomically check and either obtain
reference for existing action at index, or reserve the index slot using
a dummy entry (ERR_PTR(-EBUSY)).
This is necessary as pointers to these actions will be held after
dropping the idrinfo lock, so bumping the reference count is necessary
as we need to insert the actions, and notify userspace by dumping their
attributes. Finally, we drop the reference we took using the
tcf_action_put_many call in tcf_action_add. However, for the case where
a new action is created due to free index, its refcount remains one.
This when paired with the put_many call leads to the kernel setting up
the action, notifying userspace of its creation, and then tearing it
down. For existing actions, the refcount is still held so they remain
unaffected.
Fortunately due to rtnl_lock serialization requirement, such an action
with refcount == 1 will not be concurrently deleted by anything else, at
best CLS API can move its refcount up and down by binding to it after it
has been published from tcf_idr_insert_many. Since refcount is atleast
one until put_many call, CLS API cannot delete it. Also __tcf_action_put
release path already ensures deterministic outcome (either new action
will be created or existing action will be reused in case CLS API tries
to bind to action concurrently) due to idr lock serialization.
We fix this by making refcount of newly created actions as 2 in ACT API
replace mode. A relaxed store will suffice as visibility is ensured only
after the tcf_idr_insert_many call.
Note that in case of creation or overwriting using CLS API only (i.e.
bind = 1), overwriting existing action object is not allowed, and any
such request is silently ignored (without error).
The refcount bump that occurs in tcf_idr_check_alloc call there for
existing action will pair with tcf_exts_destroy call made from the
owner module for the same action. In case of action creation, there
is no existing action, so no tcf_exts_destroy callback happens.
This means no code changes for CLS API.
Fixes: cae422f379f3 ("net: sched: use reference counting action init")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Victor Nogueira
Peilin Ye
Davide Caratti
Paolo Abeni
Eric Dumazet
Benedikt Spranger
Marcelo Ricardo Leitner
Vlad Buslov
Kevin Bracey
Baowen Zheng
Vlad Buslov
Xin Long
Jakub Kicinski
Sebastian Andrzej Siewior
王贇
Haimin Zhang
Xiyu Yang
Hangbin Liu
Cong Wang
Yajun Deng
Pavel Skripkin
wenxu
Yang Yingliang
Boris Sukholitko
Maxim Mikityanskiy
Ariel Levkovich
Taehee Yoo
Yunsheng Lin
Du Cheng
Kumar Kartikeya Dwivedi
Pavel Tikhomirov