9506 Commits

Author SHA1 Message Date
Xin Xiong
f0351a2178 netfilter: ipt_CLUSTERIP: fix refcount leak in clusterip_tg_check()
[ Upstream commit d94a69cb2cfa77294921aae9afcfb866e723a2da ]

The issue takes place in one error path of clusterip_tg_check(). When
memcmp() returns nonzero, the function simply returns the error code,
forgetting to decrease the reference count of a clusterip_config
object, which is bumped earlier by clusterip_config_find_get(). This
may incur reference count leak.

Fix this issue by decrementing the refcount of the object in specific
error path.

Fixes: 06aa151ad1fc74 ("netfilter: ipt_CLUSTERIP: check MAC address when duplicate config is set")
Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn>
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 09:04:20 +01:00
yangxingwu
a08b8a6068 net: udp: fix alignment problem in udp4_seq_show()
[ Upstream commit 6c25449e1a32c594d743df8e8258e8ef870b6a77 ]

$ cat /pro/net/udp

before:

  sl  local_address rem_address   st tx_queue rx_queue tr tm->when
26050: 0100007F:0035 00000000:0000 07 00000000:00000000 00:00000000
26320: 0100007F:0143 00000000:0000 07 00000000:00000000 00:00000000
27135: 00000000:8472 00000000:0000 07 00000000:00000000 00:00000000

after:

   sl  local_address rem_address   st tx_queue rx_queue tr tm->when
26050: 0100007F:0035 00000000:0000 07 00000000:00000000 00:00000000
26320: 0100007F:0143 00000000:0000 07 00000000:00000000 00:00000000
27135: 00000000:8472 00000000:0000 07 00000000:00000000 00:00000000

Signed-off-by: yangxingwu <xingwu.yang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-11 13:58:50 +01:00
Muchun Song
a8e1944b44 net: fix use-after-free in tw_timer_handler
commit e22e45fc9e41bf9fcc1e92cfb78eb92786728ef0 upstream.

A real world panic issue was found as follow in Linux 5.4.

    BUG: unable to handle page fault for address: ffffde49a863de28
    PGD 7e6fe62067 P4D 7e6fe62067 PUD 7e6fe63067 PMD f51e064067 PTE 0
    RIP: 0010:tw_timer_handler+0x20/0x40
    Call Trace:
     <IRQ>
     call_timer_fn+0x2b/0x120
     run_timer_softirq+0x1ef/0x450
     __do_softirq+0x10d/0x2b8
     irq_exit+0xc7/0xd0
     smp_apic_timer_interrupt+0x68/0x120
     apic_timer_interrupt+0xf/0x20

This issue was also reported since 2017 in the thread [1],
unfortunately, the issue was still can be reproduced after fixing
DCCP.

The ipv4_mib_exit_net is called before tcp_sk_exit_batch when a net
namespace is destroyed since tcp_sk_ops is registered befrore
ipv4_mib_ops, which means tcp_sk_ops is in the front of ipv4_mib_ops
in the list of pernet_list. There will be a use-after-free on
net->mib.net_statistics in tw_timer_handler after ipv4_mib_exit_net
if there are some inflight time-wait timers.

This bug is not introduced by commit f2bf415cfed7 ("mib: add net to
NET_ADD_STATS_BH") since the net_statistics is a global variable
instead of dynamic allocation and freeing. Actually, commit
61a7e26028b9 ("mib: put net statistics on struct net") introduces
the bug since it put net statistics on struct net and free it when
net namespace is destroyed.

Moving init_ipv4_mibs() to the front of tcp_init() to fix this bug
and replace pr_crit() with panic() since continuing is meaningless
when init_ipv4_mibs() fails.

[1] https://groups.google.com/g/syzkaller/c/p1tn-_Kc6l4/m/smuL_FMAAgAJ?pli=1

Fixes: 61a7e26028b9 ("mib: put net statistics on struct net")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Cong Wang <cong.wang@bytedance.com>
Cc: Fam Zheng <fam.zheng@bytedance.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211228104145.9426-1-songmuchun@bytedance.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-05 12:35:00 +01:00
Jianguo Wu
c90d240828 udp: using datalen to cap max gso segments
commit 158390e45612ef0fde160af0826f1740c36daf21 upstream.

The max number of UDP gso segments is intended to cap to UDP_MAX_SEGMENTS,
this is checked in udp_send_skb():

    if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) {
        kfree_skb(skb);
        return -EINVAL;
    }

skb->len contains network and transport header len here, we should use
only data len instead.

Fixes: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT")
Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/900742e5-81fb-30dc-6e0b-375c6cdd7982@163.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:18:05 +01:00
liuguoqiang
4d9994fb4a net: return correct error code
[ Upstream commit 6def480181f15f6d9ec812bca8cbc62451ba314c ]

When kmemdup called failed and register_net_sysctl return NULL, should
return ENOMEM instead of ENOBUFS

Signed-off-by: liuguoqiang <liuguoqiang@uniontech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-08 08:50:11 +01:00
Eric Dumazet
1bc55e92bc tcp_cubic: fix spurious Hystart ACK train detections for not-cwnd-limited flows
[ Upstream commit 4e1fddc98d2585ddd4792b5e44433dcee7ece001 ]

While testing BIG TCP patch series, I was expecting that TCP_RR workloads
with 80KB requests/answers would send one 80KB TSO packet,
then being received as a single GRO packet.

It turns out this was not happening, and the root cause was that
cubic Hystart ACK train was triggering after a few (2 or 3) rounds of RPC.

Hystart was wrongly setting CWND/SSTHRESH to 30, while my RPC
needed a budget of ~20 segments.

Ideally these TCP_RR flows should not exit slow start.

Cubic Hystart should reset itself at each round, instead of assuming
every TCP flow is a bulk one.

Note that even after this patch, Hystart can still trigger, depending
on scheduling artifacts, but at a higher CWND/SSTHRESH threshold,
keeping optimal TSO packet sizes.

Tested:

ip link set dev eth0 gro_ipv6_max_size 131072 gso_ipv6_max_size 131072
nstat -n; netperf -H ... -t TCP_RR  -l 5  -- -r 80000,80000 -K cubic; nstat|egrep "Ip6InReceives|Hystart|Ip6OutRequests"

Before:

   8605
Ip6InReceives                   87541              0.0
Ip6OutRequests                  129496             0.0
TcpExtTCPHystartTrainDetect     1                  0.0
TcpExtTCPHystartTrainCwnd       30                 0.0

After:

  8760
Ip6InReceives                   88514              0.0
Ip6OutRequests                  87975              0.0

Fixes: ae27e98a5152 ("[TCP] CUBIC v2.3")
Co-developed-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Link: https://lore.kernel.org/r/20211123202535.1843771-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01 09:27:43 +01:00
Jon Maxwell
b4d407a646 tcp: don't free a FIN sk_buff in tcp_remove_empty_skb()
[ Upstream commit cf12e6f9124629b18a6182deefc0315f0a73a199 ]

v1: Implement a more general statement as recommended by Eric Dumazet. The
sequence number will be advanced, so this check will fix the FIN case and
other cases.

A customer reported sockets stuck in the CLOSING state. A Vmcore revealed that
the write_queue was not empty as determined by tcp_write_queue_empty() but the
sk_buff containing the FIN flag had been freed and the socket was zombied in
that state. Corresponding pcaps show no FIN from the Linux kernel on the wire.

Some instrumentation was added to the kernel and it was found that there is a
timing window where tcp_sendmsg() can run after tcp_send_fin().

tcp_sendmsg() will hit an error, for example:

1269 ▹       if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))↩
1270 ▹       ▹       goto do_error;↩

tcp_remove_empty_skb() will then free the FIN sk_buff as "skb->len == 0". The
TCP socket is now wedged in the FIN-WAIT-1 state because the FIN is never sent.

If the other side sends a FIN packet the socket will transition to CLOSING and
remain that way until the system is rebooted.

Fix this by checking for the FIN flag in the sk_buff and don't free it if that
is the case. Testing confirmed that fixed the issue.

Fixes: fdfc5c8594c2 ("tcp: remove empty skb from write queue in error cases")
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Reported-by: Monir Zouaoui <Monir.Zouaoui@mail.schwarz>
Reported-by: Simon Stier <simon.stier@mail.schwarz>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-26 11:36:11 +01:00
Eric Dumazet
6e2856767e ipv4: use siphash instead of Jenkins in fnhe_hashfun()
commit 6457378fe796815c973f631a1904e147d6ee33b1 upstream.

A group of security researchers brought to our attention
the weakness of hash function used in fnhe_hashfun().

Lets use siphash instead of Jenkins Hash, to considerably
reduce security risks.

Also remove the inline keyword, this really is distracting.

Fixes: d546c621542d ("ipv4: harden fnhe_hashfun()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
[OP: adjusted context for 4.19 stable]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-02 18:26:44 +01:00
Eric Dumazet
f6a6cced38 net: udp: annotate data race around udp_sk(sk)->corkflag
commit a9f5970767d11eadc805d5283f202612c7ba1f59 upstream.

up->corkflag field can be read or written without any lock.
Annotate accesses to avoid possible syzbot/KCSAN reports.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06 15:31:25 +02:00
Eric Dumazet
03e606e751 tcp: adjust rto_base in retransmits_timed_out()
commit 3256a2d6ab1f71f9a1bd2d7f6f18eb8108c48d17 upstream.

The cited commit exposed an old retransmits_timed_out() bug
which assumed it could call tcp_model_timeout() with
TCP_RTO_MIN as rto_base for all states.

But flows in SYN_SENT or SYN_RECV state uses a different
RTO base (1 sec instead of 200 ms, unless BPF choses
another value)

This caused a reduction of SYN retransmits from 6 to 4 with
the default /proc/sys/net/ipv4/tcp_syn_retries value.

Fixes: a41e8a88b06e ("tcp: better handle TCP_USER_TIMEOUT in SYN_SENT state")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Marek Majkowski <marek@cloudflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Qiumiao Zhang <zhangqiumiao1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06 15:31:20 +02:00
Yuchung Cheng
db0fd9c9a6 tcp: create a helper to model exponential backoff
commit 01a523b071618abbc634d1958229fe3bd2dfa5fa upstream.

Create a helper to model TCP exponential backoff for the next patch.
This is pure refactor w no behavior change.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Qiumiao Zhang <zhangqiumiao1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06 15:31:19 +02:00
Yuchung Cheng
9de7f0d60b tcp: always set retrans_stamp on recovery
commit 7ae189759cc48cf8b54beebff566e9fd2d4e7d7c upstream.

Previously TCP socket's retrans_stamp is not set if the
retransmission has failed to send. As a result if a socket is
experiencing local issues to retransmit packets, determining when
to abort a socket is complicated w/o knowning the starting time of
the recovery since retrans_stamp may remain zero.

This complication causes sub-optimal behavior that TCP may use the
latest, instead of the first, retransmission time to compute the
elapsed time of a stalling connection due to local issues. Then TCP
may disrecard TCP retries settings and keep retrying until it finally
succeed: not a good idea when the local host is already strained.

The simple fix is to always timestamp the start of a recovery.
It's worth noting that retrans_stamp is also used to compare echo
timestamp values to detect spurious recovery. This patch does
not break that because retrans_stamp is still later than when the
original packet was sent.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Qiumiao Zhang <zhangqiumiao1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06 15:31:19 +02:00
Eric Dumazet
eb6eeb056c tcp: address problems caused by EDT misshaps
commit 9efdda4e3abed13f0903b7b6e4d4c2102019440a upstream.

When a qdisc setup including pacing FQ is dismantled and recreated,
some TCP packets are sent earlier than instructed by TCP stack.

TCP can be fooled when ACK comes back, because the following
operation can return a negative value.

    tcp_time_stamp(tp) - tp->rx_opt.rcv_tsecr;

Some paths in TCP stack were not dealing properly with this,
this patch addresses four of them.

Fixes: ab408b6dc744 ("tcp: switch tcp and sch_fq to new earliest departure time model")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Qiumiao Zhang <zhangqiumiao1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06 15:31:19 +02:00
Willem de Bruijn
774430026b ip_gre: validate csum_start only on pull
[ Upstream commit 8a0ed250f911da31a2aef52101bc707846a800ff ]

The GRE tunnel device can pull existing outer headers in ipge_xmit.
This is a rare path, apparently unique to this device. The below
commit ensured that pulling does not move skb->data beyond csum_start.

But it has a false positive if ip_summed is not CHECKSUM_PARTIAL and
thus csum_start is irrelevant.

Refine to exclude this. At the same time simplify and strengthen the
test.

Simplify, by moving the check next to the offending pull, making it
more self documenting and removing an unnecessary branch from other
code paths.

Strengthen, by also ensuring that the transport header is correct and
therefore the inner headers will be after skb_reset_inner_headers.
The transport header is set to csum_start in skb_partial_csum_set.

Link: https://lore.kernel.org/netdev/YS+h%2FtqCJJiQei+W@shredder/
Fixes: 1d011c4803c7 ("ip_gre: add validation for csum_start")
Reported-by: Ido Schimmel <idosch@idosch.org>
Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-22 11:48:14 +02:00
zhenggy
dfefcc4635 tcp: fix tp->undo_retrans accounting in tcp_sacktag_one()
commit 4f884f3962767877d7aabbc1ec124d2c307a4257 upstream.

Commit 10d3be569243 ("tcp-tso: do not split TSO packets at retransmit
time") may directly retrans a multiple segments TSO/GSO packet without
split, Since this commit, we can no longer assume that a retransmitted
packet is a single segment.

This patch fixes the tp->undo_retrans accounting in tcp_sacktag_one()
that use the actual segments(pcount) of the retransmitted packet.

Before that commit (10d3be569243), the assumption underlying the
tp->undo_retrans-- seems correct.

Fixes: 10d3be569243 ("tcp-tso: do not split TSO packets at retransmit time")
Signed-off-by: zhenggy <zhenggy@chinatelecom.cn>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22 11:48:12 +02:00
Luke Hsiao
6b0d36222f tcp: enable data-less, empty-cookie SYN with TFO_SERVER_COOKIE_NOT_REQD
[ Upstream commit e3faa49bcecdfcc80e94dd75709d6acb1a5d89f6 ]

Since the original TFO server code was implemented in commit
168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef ("tcp: TCP Fast Open Server -
main code path") the TFO server code has supported the sysctl bit flag
TFO_SERVER_COOKIE_NOT_REQD. Currently, when the TFO_SERVER_ENABLE and
TFO_SERVER_COOKIE_NOT_REQD sysctl bit flags are set, a server connection
will accept a SYN with N bytes of data (N > 0) that has no TFO cookie,
create a new fast open connection, process the incoming data in the SYN,
and make the connection ready for accepting. After accepting, the
connection is ready for read()/recvmsg() to read the N bytes of data in
the SYN, ready for write()/sendmsg() calls and data transmissions to
transmit data.

This commit changes an edge case in this feature by changing this
behavior to apply to (N >= 0) bytes of data in the SYN rather than only
(N > 0) bytes of data in the SYN. Now, a server will accept a data-less
SYN without a TFO cookie if TFO_SERVER_COOKIE_NOT_REQD is set.

Caveat! While this enables a new kind of TFO (data-less empty-cookie
SYN), some firewall rules setup may not work if they assume such packets
are not legit TFOs and will filter them.

Signed-off-by: Luke Hsiao <lukehsiao@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20210816205105.2533289-1-luke.w.hsiao@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-22 11:48:07 +02:00
Gustavo A. R. Silva
8c197826e2 ipv4: ip_output.c: Fix out-of-bounds warning in ip_copy_addrs()
[ Upstream commit 6321c7acb82872ef6576c520b0e178eaad3a25c0 ]

Fix the following out-of-bounds warning:

    In function 'ip_copy_addrs',
        inlined from '__ip_queue_xmit' at net/ipv4/ip_output.c:517:2:
net/ipv4/ip_output.c:449:2: warning: 'memcpy' offset [40, 43] from the object at 'fl' is out of the bounds of referenced subobject 'saddr' with type 'unsigned int' at offset 36 [-Warray-bounds]
      449 |  memcpy(&iph->saddr, &fl4->saddr,
          |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      450 |         sizeof(fl4->saddr) + sizeof(fl4->daddr));
          |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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(). This causes a legitimate compiler warning because memcpy()
overruns the length of &iph->saddr and &fl4->saddr. As these are just
a couple of struct members, fix this by using direct assignments,
instead of 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>
2021-09-22 11:48:04 +02:00
Eric Dumazet
1d3e3d5697 ipv4: fix endianness issue in inet_rtm_getroute_build_skb()
[ Upstream commit 92548b0ee220e000d81c27ac9a80e0ede895a881 ]

The UDP length field should be in network order.
This removes the following sparse error:

net/ipv4/route.c:3173:27: warning: incorrect type in assignment (different base types)
net/ipv4/route.c:3173:27:    expected restricted __be16 [usertype] len
net/ipv4/route.c:3173:27:    got unsigned long

Fixes: 404eb77ea766 ("ipv4: support sport, dport and ip_proto in RTM_GETROUTE")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: David Ahern <dsahern@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-22 11:47:55 +02:00
Eric Dumazet
3e6bd2b583 ipv4: make exception cache less predictible
[ Upstream commit 67d6d681e15b578c1725bad8ad079e05d1c48a8e ]

Even after commit 6457378fe796 ("ipv4: use siphash instead of Jenkins in
fnhe_hashfun()"), an attacker can still use brute force to learn
some secrets from a victim linux host.

One way to defeat these attacks is to make the max depth of the hash
table bucket a random value.

Before this patch, each bucket of the hash table used to store exceptions
could contain 6 items under attack.

After the patch, each bucket would contains a random number of items,
between 6 and 10. The attacker can no longer infer secrets.

This is slightly increasing memory size used by the hash table,
by 50% in average, we do not expect this to be a problem.

This patch is more complex than the prior one (IPv6 equivalent),
because IPv4 was reusing the oldest entry.
Since we need to be able to evict more than one entry per
update_or_create_fnhe() call, I had to replace
fnhe_oldest() with fnhe_remove_oldest().

Also note that we will queue extra kfree_rcu() calls under stress,
which hopefully wont be a too big issue.

Fixes: 4895c771c7f0 ("ipv4: Add FIB nexthop exceptions.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: David Ahern <dsahern@kernel.org>
Tested-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-22 11:47:55 +02:00
Martin KaFai Lau
15bf24c5fb tcp: seq_file: Avoid skipping sk during tcp_seek_last_pos
[ Upstream commit 525e2f9fd0229eb10cb460a9e6d978257f24804e ]

st->bucket stores the current bucket number.
st->offset stores the offset within this bucket that is the sk to be
seq_show().  Thus, st->offset only makes sense within the same
st->bucket.

These two variables are an optimization for the common no-lseek case.
When resuming the seq_file iteration (i.e. seq_start()),
tcp_seek_last_pos() tries to continue from the st->offset
at bucket st->bucket.

However, it is possible that the bucket pointed by st->bucket
has changed and st->offset may end up skipping the whole st->bucket
without finding a sk.  In this case, tcp_seek_last_pos() currently
continues to satisfy the offset condition in the next (and incorrect)
bucket.  Instead, regardless of the offset value, the first sk of the
next bucket should be returned.  Thus, "bucket == st->bucket" check is
added to tcp_seek_last_pos().

The chance of hitting this is small and the issue is a decade old,
so targeting for the next tree.

Fixes: a8b690f98baf ("tcp: Fix slowness in read /proc/net/tcp")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210701200541.1033917-1-kafai@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-22 11:47:52 +02:00
Mathieu Desnoyers
69178f2d65 ipv4/icmp: l3mdev: Perform icmp error route lookup on source device routing table (v2)
commit e1e84eb58eb494b77c8389fc6308b5042dcce791 upstream.

As per RFC792, ICMP errors should be sent to the source host.

However, in configurations with Virtual Routing and Forwarding tables,
looking up which routing table to use is currently done by using the
destination net_device.

commit 9d1a6c4ea43e ("net: icmp_route_lookup should use rt dev to
determine L3 domain") changes the interface passed to
l3mdev_master_ifindex() and inet_addr_type_dev_table() from skb_in->dev
to skb_dst(skb_in)->dev. This effectively uses the destination device
rather than the source device for choosing which routing table should be
used to lookup where to send the ICMP error.

Therefore, if the source and destination interfaces are within separate
VRFs, or one in the global routing table and the other in a VRF, looking
up the source host in the destination interface's routing table will
fail if the destination interface's routing table contains no route to
the source host.

One observable effect of this issue is that traceroute does not work in
the following cases:

- Route leaking between global routing table and VRF
- Route leaking between VRFs

Preferably use the source device routing table when sending ICMP error
messages. If no source device is set, fall-back on the destination
device routing table. Else, use the main routing table (index 0).

[ It has been pointed out that a similar issue may exist with ICMP
  errors triggered when forwarding between network namespaces. It would
  be worthwhile to investigate, but is outside of the scope of this
  investigation. ]

[ It has also been pointed out that a similar issue exists with
  unreachable / fragmentation needed messages, which can be triggered by
  changing the MTU of eth1 in r1 to 1400 and running:

  ip netns exec h1 ping -s 1450 -Mdo -c1 172.16.2.2

  Some investigation points to raw_icmp_error() and raw_err() as being
  involved in this last scenario. The focus of this patch is TTL expired
  ICMP messages, which go through icmp_route_lookup.
  Investigation of failure modes related to raw_icmp_error() is beyond
  this investigation's scope. ]

Fixes: 9d1a6c4ea43e ("net: icmp_route_lookup should use rt dev to determine L3 domain")
Link: https://tools.ietf.org/html/rfc792
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22 11:47:47 +02:00
Liu Jian
4768973dff igmp: Add ip_mc_list lock in ip_check_mc_rcu
commit 23d2b94043ca8835bd1e67749020e839f396a1c2 upstream.

I got below panic when doing fuzz test:

Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 4056 Comm: syz-executor.3 Tainted: G    B             5.14.0-rc1-00195-gcff5c4254439-dirty #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack_lvl+0x7a/0x9b
panic+0x2cd/0x5af
end_report.cold+0x5a/0x5a
kasan_report+0xec/0x110
ip_check_mc_rcu+0x556/0x5d0
__mkroute_output+0x895/0x1740
ip_route_output_key_hash_rcu+0x2d0/0x1050
ip_route_output_key_hash+0x182/0x2e0
ip_route_output_flow+0x28/0x130
udp_sendmsg+0x165d/0x2280
udpv6_sendmsg+0x121e/0x24f0
inet6_sendmsg+0xf7/0x140
sock_sendmsg+0xe9/0x180
____sys_sendmsg+0x2b8/0x7a0
___sys_sendmsg+0xf0/0x160
__sys_sendmmsg+0x17e/0x3c0
__x64_sys_sendmmsg+0x9e/0x100
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x462eb9
Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3df5af1c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462eb9
RDX: 0000000000000312 RSI: 0000000020001700 RDI: 0000000000000007
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3df5af26bc
R13: 00000000004c372d R14: 0000000000700b10 R15: 00000000ffffffff

It is one use-after-free in ip_check_mc_rcu.
In ip_mc_del_src, the ip_sf_list of pmc has been freed under pmc->lock protection.
But access to ip_sf_list in ip_check_mc_rcu is not protected by the lock.

Signed-off-by: Liu Jian <liujian56@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22 11:47:47 +02:00
Shreyansh Chouhan
c33471daf2 ip_gre: add validation for csum_start
[ Upstream commit 1d011c4803c72f3907eccfc1ec63caefb852fcbf ]

Validate csum_start in gre_handle_offloads before we call _gre_xmit so
that we do not crash later when the csum_start value is used in the
lco_csum function call.

This patch deals with ipv4 code.

Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.")
Reported-by: syzbot+ff8e1b9f2f36481e2efc@syzkaller.appspotmail.com
Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh630@gmail.com>
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>
2021-09-03 09:58:01 +02:00
Eric Dumazet
ec75ebd164 net: igmp: increase size of mr_ifc_count
[ Upstream commit b69dd5b3780a7298bd893816a09da751bc0636f7 ]

Some arches support cmpxchg() on 4-byte and 8-byte only.
Increase mr_ifc_count width to 32bit to fix this problem.

Fixes: 4a2b285e7e10 ("net: igmp: fix data-race in igmp_ifc_timer_expire()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210811195715.3684218-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-26 08:36:39 -04:00
Neal Cardwell
32b6627fec tcp_bbr: fix u32 wrap bug in round logic if bbr_init() called after 2B packets
[ Upstream commit 6de035fec045f8ae5ee5f3a02373a18b939e91fb ]

Currently if BBR congestion control is initialized after more than 2B
packets have been delivered, depending on the phase of the
tp->delivered counter the tracking of BBR round trips can get stuck.

The bug arises because if tp->delivered is between 2^31 and 2^32 at
the time the BBR congestion control module is initialized, then the
initialization of bbr->next_rtt_delivered to 0 will cause the logic to
believe that the end of the round trip is still billions of packets in
the future. More specifically, the following check will fail
repeatedly:

  !before(rs->prior_delivered, bbr->next_rtt_delivered)

and thus the connection will take up to 2B packets delivered before
that check will pass and the connection will set:

  bbr->round_start = 1;

This could cause many mechanisms in BBR to fail to trigger, for
example bbr_check_full_bw_reached() would likely never exit STARTUP.

This bug is 5 years old and has not been observed, and as a practical
matter this would likely rarely trigger, since it would require
transferring at least 2B packets, or likely more than 3 terabytes of
data, before switching congestion control algorithms to BBR.

This patch is a stable candidate for kernels as far back as v4.9,
when tcp_bbr.c was added.

Fixes: 0f8782ea1497 ("tcp_bbr: add BBR congestion control")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Kevin Yang <yyd@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20210811024056.235161-1-ncardwell@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-26 08:36:39 -04:00
Eric Dumazet
fb5db31060 net: igmp: fix data-race in igmp_ifc_timer_expire()
[ Upstream commit 4a2b285e7e103d4d6c6ed3e5052a0ff74a5d7f15 ]

Fix the data-race reported by syzbot [1]
Issue here is that igmp_ifc_timer_expire() can update in_dev->mr_ifc_count
while another change just occured from another context.

in_dev->mr_ifc_count is only 8bit wide, so the race had little
consequences.

[1]
BUG: KCSAN: data-race in igmp_ifc_event / igmp_ifc_timer_expire

write to 0xffff8881051e3062 of 1 bytes by task 12547 on cpu 0:
 igmp_ifc_event+0x1d5/0x290 net/ipv4/igmp.c:821
 igmp_group_added+0x462/0x490 net/ipv4/igmp.c:1356
 ____ip_mc_inc_group+0x3ff/0x500 net/ipv4/igmp.c:1461
 __ip_mc_join_group+0x24d/0x2c0 net/ipv4/igmp.c:2199
 ip_mc_join_group_ssm+0x20/0x30 net/ipv4/igmp.c:2218
 do_ip_setsockopt net/ipv4/ip_sockglue.c:1285 [inline]
 ip_setsockopt+0x1827/0x2a80 net/ipv4/ip_sockglue.c:1423
 tcp_setsockopt+0x8c/0xa0 net/ipv4/tcp.c:3657
 sock_common_setsockopt+0x5d/0x70 net/core/sock.c:3362
 __sys_setsockopt+0x18f/0x200 net/socket.c:2159
 __do_sys_setsockopt net/socket.c:2170 [inline]
 __se_sys_setsockopt net/socket.c:2167 [inline]
 __x64_sys_setsockopt+0x62/0x70 net/socket.c:2167
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881051e3062 of 1 bytes by interrupt on cpu 1:
 igmp_ifc_timer_expire+0x706/0xa30 net/ipv4/igmp.c:808
 call_timer_fn+0x2e/0x1d0 kernel/time/timer.c:1419
 expire_timers+0x135/0x250 kernel/time/timer.c:1464
 __run_timers+0x358/0x420 kernel/time/timer.c:1732
 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1745
 __do_softirq+0x12c/0x26e kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x9a/0xb0 kernel/softirq.c:636
 sysvec_apic_timer_interrupt+0x69/0x80 arch/x86/kernel/apic/apic.c:1100
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
 console_unlock+0x8e8/0xb30 kernel/printk/printk.c:2646
 vprintk_emit+0x125/0x3d0 kernel/printk/printk.c:2174
 vprintk_default+0x22/0x30 kernel/printk/printk.c:2185
 vprintk+0x15a/0x170 kernel/printk/printk_safe.c:392
 printk+0x62/0x87 kernel/printk/printk.c:2216
 selinux_netlink_send+0x399/0x400 security/selinux/hooks.c:6041
 security_netlink_send+0x42/0x90 security/security.c:2070
 netlink_sendmsg+0x59e/0x7c0 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:703 [inline]
 sock_sendmsg net/socket.c:723 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2392
 ___sys_sendmsg net/socket.c:2446 [inline]
 __sys_sendmsg+0x1ed/0x270 net/socket.c:2475
 __do_sys_sendmsg net/socket.c:2484 [inline]
 __se_sys_sendmsg net/socket.c:2482 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2482
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x01 -> 0x02

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12539 Comm: syz-executor.1 Not tainted 5.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
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>
2021-08-26 08:36:38 -04:00
Eric Dumazet
86aef177e0 net/tcp_fastopen: fix data races around tfo_active_disable_stamp
[ Upstream commit 6f20c8adb1813467ea52c1296d52c4e95978cb2f ]

tfo_active_disable_stamp is read and written locklessly.
We need to annotate these accesses appropriately.

Then, we need to perform the atomic_inc(tfo_active_disable_times)
after the timestamp has been updated, and thus add barriers
to make sure tcp_fastopen_active_should_disable() wont read
a stale timestamp.

Fixes: cf1ef3f0719b ("net/tcp_fastopen: Disable active side TFO in certain scenarios")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28 11:13:48 +02:00
Hangbin Liu
be680f4bf7 net: ip_tunnel: fix mtu calculation for ETHER tunnel devices
commit 9992a078b1771da354ac1f9737e1e639b687caa2 upstream.

Commit 28e104d00281 ("net: ip_tunnel: fix mtu calculation") removed
dev->hard_header_len subtraction when calculate MTU for tunnel devices
as there is an overhead for device that has header_ops.

But there are ETHER tunnel devices, like gre_tap or erspan, which don't
have header_ops but set dev->hard_header_len during setup. This makes
pkts greater than (MTU - ETH_HLEN) could not be xmited. Fix it by
subtracting the ETHER tunnel devices' dev->hard_header_len for MTU
calculation.

Fixes: 28e104d00281 ("net: ip_tunnel: fix mtu calculation")
Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-28 11:13:46 +02:00
Eric Dumazet
dd1f607cad udp: annotate data races around unix_sk(sk)->gso_size
commit 18a419bad63b7f68a1979e28459782518e7b6bbe upstream.

Accesses to unix_sk(sk)->gso_size are lockless.
Add READ_ONCE()/WRITE_ONCE() around them.

BUG: KCSAN: data-race in udp_lib_setsockopt / udpv6_sendmsg

write to 0xffff88812d78f47c of 2 bytes by task 10849 on cpu 1:
 udp_lib_setsockopt+0x3b3/0x710 net/ipv4/udp.c:2696
 udpv6_setsockopt+0x63/0x90 net/ipv6/udp.c:1630
 sock_common_setsockopt+0x5d/0x70 net/core/sock.c:3265
 __sys_setsockopt+0x18f/0x200 net/socket.c:2104
 __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 0xffff88812d78f47c of 2 bytes by task 10852 on cpu 0:
 udpv6_sendmsg+0x161/0x16b0 net/ipv6/udp.c:1299
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:642
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2337
 ___sys_sendmsg net/socket.c:2391 [inline]
 __sys_sendmmsg+0x315/0x4b0 net/socket.c:2477
 __do_sys_sendmmsg net/socket.c:2506 [inline]
 __se_sys_sendmmsg net/socket.c:2503 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2503
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000 -> 0x0005

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10852 Comm: syz-executor.0 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@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>
2021-07-28 11:13:46 +02:00
Eric Dumazet
4818f18704 ipv6: tcp: drop silly ICMPv6 packet too big messages
commit c7bb4b89033b764eb07db4e060548a6311d801ee upstream.

While TCP stack scales reasonably well, there is still one part that
can be used to DDOS it.

IPv6 Packet too big messages have to lookup/insert a new route,
and if abused by attackers, can easily put hosts under high stress,
with many cpus contending on a spinlock while one is stuck in fib6_run_gc()

ip6_protocol_deliver_rcu()
 icmpv6_rcv()
  icmpv6_notify()
   tcp_v6_err()
    tcp_v6_mtu_reduced()
     inet6_csk_update_pmtu()
      ip6_rt_update_pmtu()
       __ip6_rt_update_pmtu()
        ip6_rt_cache_alloc()
         ip6_dst_alloc()
          dst_alloc()
           ip6_dst_gc()
            fib6_run_gc()
             spin_lock_bh() ...

Some of our servers have been hit by malicious ICMPv6 packets
trying to _increase_ the MTU/MSS of TCP flows.

We believe these ICMPv6 packets are a result of a bug in one ISP stack,
since they were blindly sent back for _every_ (small) packet sent to them.

These packets are for one TCP flow:
09:24:36.266491 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.266509 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.316688 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.316704 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.608151 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240

TCP stack can filter some silly requests :

1) MTU below IPV6_MIN_MTU can be filtered early in tcp_v6_err()
2) tcp_v6_mtu_reduced() can drop requests trying to increase current MSS.

This tests happen before the IPv6 routing stack is entered, thus
removing the potential contention and route exhaustion.

Note that IPv6 stack was performing these checks, but too late
(ie : after the route has been added, and after the potential
garbage collect war)

v2: fix typo caught by Martin, thanks !
v3: exports tcp_mtu_to_mss(), caught by David, thanks !

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-28 11:13:45 +02:00
Eric Dumazet
d694db2f90 tcp: annotate data races around tp->mtu_info
commit 561022acb1ce62e50f7a8258687a21b84282a4cb upstream.

While tp->mtu_info is read while socket is owned, the write
sides happen from err handlers (tcp_v[46]_mtu_reduced)
which only own the socket spinlock.

Fixes: 563d34d05786 ("tcp: dont drop MTU reduction indications")
Signed-off-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 11:13:45 +02:00
Jakub Kicinski
a847a5e256 net: ip: avoid OOM kills with large UDP sends over loopback
[ Upstream commit 6d123b81ac615072a8525c13c6c41b695270a15d ]

Dave observed number of machines hitting OOM on the UDP send
path. The workload seems to be sending large UDP packets over
loopback. Since loopback has MTU of 64k kernel will try to
allocate an skb with up to 64k of head space. This has a good
chance of failing under memory pressure. What's worse if
the message length is <32k the allocation may trigger an
OOM killer.

This is entirely avoidable, we can use an skb with page frags.

af_unix solves a similar problem by limiting the head
length to SKB_MAX_ALLOC. This seems like a good and simple
approach. It means that UDP messages > 16kB will now
use fragments if underlying device supports SG, if extra
allocator pressure causes regressions in real workloads
we can switch to trying the large allocation first and
falling back.

v4: pre-calculate all the additions to alloclen so
    we can be sure it won't go over order-2

Reported-by: Dave Jones <dsj@fb.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>
2021-07-20 16:16:02 +02:00
Vadim Fedorenko
d76613a914 net: lwtunnel: handle MTU calculation in forwading
[ Upstream commit fade56410c22cacafb1be9f911a0afd3701d8366 ]

Commit 14972cbd34ff ("net: lwtunnel: Handle fragmentation") moved
fragmentation logic away from lwtunnel by carry encap headroom and
use it in output MTU calculation. But the forwarding part was not
covered and created difference in MTU for output and forwarding and
further to silent drops on ipv4 forwarding path. Fix it by taking
into account lwtunnel encap headroom.

The same commit also introduced difference in how to treat RTAX_MTU
in IPv4 and IPv6 where latter explicitly removes lwtunnel encap
headroom from route MTU. Make IPv4 version do the same.

Fixes: 14972cbd34ff ("net: lwtunnel: Handle fragmentation")
Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20 16:15:52 +02:00
Miao Wang
0cb6b100b8 net/ipv4: swap flow ports when validating source
[ Upstream commit c69f114d09891adfa3e301a35d9e872b8b7b5a50 ]

When doing source address validation, the flowi4 struct used for
fib_lookup should be in the reverse direction to the given skb.
fl4_dport and fl4_sport returned by fib4_rules_early_flow_dissect
should thus be swapped.

Fixes: 5a847a6e1477 ("net/ipv4: Initialize proto and ports in flow struct")
Signed-off-by: Miao Wang <shankerwangmiao@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20 16:15:51 +02:00
Zheng Yongjun
1d86498c25 ping: Check return value of function 'ping_queue_rcv_skb'
[ Upstream commit 9d44fa3e50cc91691896934d106c86e4027e61ca ]

Function 'ping_queue_rcv_skb' not always return success, which will
also return fail. If not check the wrong return value of it, lead to function
`ping_rcv` return success.

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>
2021-06-30 08:48:30 -04:00
Eric Dumazet
7f7e23df85 inet: use bigger hash table for IP ID generation
commit aa6dd211e4b1dde9d5dc25d699d35f789ae7eeba upstream.

In commit 73f156a6e8c1 ("inetpeer: get rid of ip_id_count")
I used a very small hash table that could be abused
by patient attackers to reveal sensitive information.

Switch to a dynamic sizing, depending on RAM size.

Typical big hosts will now use 128x more storage (2 MB)
to get a similar increase in security and reduction
of hash collisions.

As a bonus, use of alloc_large_system_hash() spreads
allocated memory among all NUMA nodes.

Fixes: 73f156a6e8c1 ("inetpeer: get rid of ip_id_count")
Reported-by: Amit Klein <aksecurity@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-30 08:48:27 -04:00
Toke Høiland-Jørgensen
3bf50dc858 icmp: don't send out ICMP messages with a source address of 0.0.0.0
[ Upstream commit 321827477360934dc040e9d3c626bf1de6c3ab3c ]

When constructing ICMP response messages, the kernel will try to pick a
suitable source address for the outgoing packet. However, if no IPv4
addresses are configured on the system at all, this will fail and we end up
producing an ICMP message with a source address of 0.0.0.0. This can happen
on a box routing IPv4 traffic via v6 nexthops, for instance.

Since 0.0.0.0 is not generally routable on the internet, there's a good
chance that such ICMP messages will never make it back to the sender of the
original packet that the ICMP message was sent in response to. This, in
turn, can create connectivity and PMTUd problems for senders. Fortunately,
RFC7600 reserves a dummy address to be used as a source for ICMP
messages (192.0.0.8/32), so let's teach the kernel to substitute that
address as a last resort if the regular source address selection procedure
fails.

Below is a quick example reproducing this issue with network namespaces:

ip netns add ns0
ip l add type veth peer netns ns0
ip l set dev veth0 up
ip a add 10.0.0.1/24 dev veth0
ip a add fc00:dead:cafe:42::1/64 dev veth0
ip r add 10.1.0.0/24 via inet6 fc00:dead:cafe:42::2
ip -n ns0 l set dev veth0 up
ip -n ns0 a add fc00:dead:cafe:42::2/64 dev veth0
ip -n ns0 r add 10.0.0.0/24 via inet6 fc00:dead:cafe:42::1
ip netns exec ns0 sysctl -w net.ipv4.icmp_ratelimit=0
ip netns exec ns0 sysctl -w net.ipv4.ip_forward=1
tcpdump -tpni veth0 -c 2 icmp &
ping -w 1 10.1.0.1 > /dev/null
tcpdump: verbose output suppressed, use -v[v]... for full protocol decode
listening on veth0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
IP 10.0.0.1 > 10.1.0.1: ICMP echo request, id 29, seq 1, length 64
IP 0.0.0.0 > 10.0.0.1: ICMP net 10.1.0.1 unreachable, length 92
2 packets captured
2 packets received by filter
0 packets dropped by kernel

With this patch the above capture changes to:
IP 10.0.0.1 > 10.1.0.1: ICMP echo request, id 31127, seq 1, length 64
IP 192.0.0.8 > 10.0.0.1: ICMP net 10.1.0.1 unreachable, length 92

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Juliusz Chroboczek <jch@irif.fr>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-30 08:48:21 -04:00
Chengyang Fan
1e28018b5c net: ipv4: fix memory leak in ip_mc_add1_src
[ Upstream commit d8e2973029b8b2ce477b564824431f3385c77083 ]

BUG: memory leak
unreferenced object 0xffff888101bc4c00 (size 32):
  comm "syz-executor527", pid 360, jiffies 4294807421 (age 19.329s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
    01 00 00 00 00 00 00 00 ac 14 14 bb 00 00 02 00 ................
  backtrace:
    [<00000000f17c5244>] kmalloc include/linux/slab.h:558 [inline]
    [<00000000f17c5244>] kzalloc include/linux/slab.h:688 [inline]
    [<00000000f17c5244>] ip_mc_add1_src net/ipv4/igmp.c:1971 [inline]
    [<00000000f17c5244>] ip_mc_add_src+0x95f/0xdb0 net/ipv4/igmp.c:2095
    [<000000001cb99709>] ip_mc_source+0x84c/0xea0 net/ipv4/igmp.c:2416
    [<0000000052cf19ed>] do_ip_setsockopt net/ipv4/ip_sockglue.c:1294 [inline]
    [<0000000052cf19ed>] ip_setsockopt+0x114b/0x30c0 net/ipv4/ip_sockglue.c:1423
    [<00000000477edfbc>] raw_setsockopt+0x13d/0x170 net/ipv4/raw.c:857
    [<00000000e75ca9bb>] __sys_setsockopt+0x158/0x270 net/socket.c:2117
    [<00000000bdb993a8>] __do_sys_setsockopt net/socket.c:2128 [inline]
    [<00000000bdb993a8>] __se_sys_setsockopt net/socket.c:2125 [inline]
    [<00000000bdb993a8>] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2125
    [<000000006a1ffdbd>] do_syscall_64+0x40/0x80 arch/x86/entry/common.c:47
    [<00000000b11467c4>] entry_SYSCALL_64_after_hwframe+0x44/0xae

In commit 24803f38a5c0 ("igmp: do not remove igmp souce list info when set
link down"), the ip_mc_clear_src() in ip_mc_destroy_dev() was removed,
because it was also called in igmpv3_clear_delrec().

Rough callgraph:

inetdev_destroy
-> ip_mc_destroy_dev
     -> igmpv3_clear_delrec
        -> ip_mc_clear_src
-> RCU_INIT_POINTER(dev->ip_ptr, NULL)

However, ip_mc_clear_src() called in igmpv3_clear_delrec() doesn't
release in_dev->mc_list->sources. And RCU_INIT_POINTER() assigns the
NULL to dev->ip_ptr. As a result, in_dev cannot be obtained through
inetdev_by_index() and then in_dev->mc_list->sources cannot be released
by ip_mc_del1_src() in the sock_close. Rough call sequence goes like:

sock_close
-> __sock_release
   -> inet_release
      -> ip_mc_drop_socket
         -> inetdev_by_index
         -> ip_mc_leave_src
            -> ip_mc_del_src
               -> ip_mc_del1_src

So we still need to call ip_mc_clear_src() in ip_mc_destroy_dev() to free
in_dev->mc_list->sources.

Fixes: 24803f38a5c0 ("igmp: do not remove igmp souce list info ...")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Chengyang Fan <cy.fan@huawei.com>
Acked-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-30 08:48:20 -04:00
Paolo Abeni
2f73448041 udp: fix race between close() and udp_abort()
[ Upstream commit a8b897c7bcd47f4147d066e22cc01d1026d7640e ]

Kaustubh reported and diagnosed a panic in udp_lib_lookup().
The root cause is udp_abort() racing with close(). Both
racing functions acquire the socket lock, but udp{v6}_destroy_sock()
release it before performing destructive actions.

We can't easily extend the socket lock scope to avoid the race,
instead use the SOCK_DEAD flag to prevent udp_abort from doing
any action when the critical race happens.

Diagnosed-and-tested-by: Kaustubh Pandey <kapandey@codeaurora.org>
Fixes: 5d77dca82839 ("net: diag: support SOCK_DESTROY for UDP sockets")
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>
2021-06-30 08:48:16 -04:00
Nanyong Sun
5340858147 net: ipv4: fix memory leak in netlbl_cipsov4_add_std
[ Upstream commit d612c3f3fae221e7ea736d196581c2217304bbbc ]

Reported by syzkaller:
BUG: memory leak
unreferenced object 0xffff888105df7000 (size 64):
comm "syz-executor842", pid 360, jiffies 4294824824 (age 22.546s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000e67ed558>] kmalloc include/linux/slab.h:590 [inline]
[<00000000e67ed558>] kzalloc include/linux/slab.h:720 [inline]
[<00000000e67ed558>] netlbl_cipsov4_add_std net/netlabel/netlabel_cipso_v4.c:145 [inline]
[<00000000e67ed558>] netlbl_cipsov4_add+0x390/0x2340 net/netlabel/netlabel_cipso_v4.c:416
[<0000000006040154>] genl_family_rcv_msg_doit.isra.0+0x20e/0x320 net/netlink/genetlink.c:739
[<00000000204d7a1c>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
[<00000000204d7a1c>] genl_rcv_msg+0x2bf/0x4f0 net/netlink/genetlink.c:800
[<00000000c0d6a995>] netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2504
[<00000000d78b9d2c>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
[<000000009733081b>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
[<000000009733081b>] netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1340
[<00000000d5fd43b8>] netlink_sendmsg+0x789/0xc70 net/netlink/af_netlink.c:1929
[<000000000a2d1e40>] sock_sendmsg_nosec net/socket.c:654 [inline]
[<000000000a2d1e40>] sock_sendmsg+0x139/0x170 net/socket.c:674
[<00000000321d1969>] ____sys_sendmsg+0x658/0x7d0 net/socket.c:2350
[<00000000964e16bc>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2404
[<000000001615e288>] __sys_sendmsg+0xd3/0x190 net/socket.c:2433
[<000000004ee8b6a5>] do_syscall_64+0x37/0x90 arch/x86/entry/common.c:47
[<00000000171c7cee>] entry_SYSCALL_64_after_hwframe+0x44/0xae

The memory of doi_def->map.std pointing is allocated in
netlbl_cipsov4_add_std, but no place has freed it. It should be
freed in cipso_v4_doi_free which frees the cipso DOI resource.

Fixes: 96cb8e3313c7a ("[NetLabel]: CIPSOv4 and Unlabeled packet integration")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-30 08:48:15 -04:00
Josh Triplett
51c0007f4c net: ipconfig: Don't override command-line hostnames or domains
[ Upstream commit b508d5fb69c2211a1b860fc058aafbefc3b3c3cd ]

If the user specifies a hostname or domain name as part of the ip=
command-line option, preserve it and don't overwrite it with one
supplied by DHCP/BOOTP.

For instance, ip=::::myhostname::dhcp will use "myhostname" rather than
ignoring and overwriting it.

Fix the comment on ic_bootp_string that suggests it only copies a string
"if not already set"; it doesn't have any such logic.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-30 08:48:13 -04:00
Jonathon Reinhart
992de06308 net: Only allow init netns to set default tcp cong to a restricted algo
commit 8d432592f30fcc34ef5a10aac4887b4897884493 upstream.

tcp_set_default_congestion_control() is netns-safe in that it writes
to &net->ipv4.tcp_congestion_control, but it also sets
ca->flags |= TCP_CONG_NON_RESTRICTED which is not namespaced.
This has the unintended side-effect of changing the global
net.ipv4.tcp_allowed_congestion_control sysctl, despite the fact that it
is read-only: 97684f0970f6 ("net: Make tcp_allowed_congestion_control
readonly in non-init netns")

Resolve this netns "leak" by only allowing the init netns to set the
default algorithm to one that is restricted. This restriction could be
removed if tcp_allowed_congestion_control were namespace-ified in the
future.

This bug was uncovered with
https://github.com/JonathonReinhart/linux-netns-sysctl-verify

Fixes: 6670e1524477 ("tcp: Namespace-ify sysctl_tcp_default_congestion_control")
Signed-off-by: Jonathon Reinhart <jonathon.reinhart@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:59:39 +02:00
Florian Westphal
12ec80252e netfilter: x_tables: fix compat match/target pad out-of-bound write
commit b29c457a6511435960115c0f548c4360d5f4801d upstream.

xt_compat_match/target_from_user doesn't check that zeroing the area
to start of next rule won't write past end of allocated ruleset blob.

Remove this code and zero the entire blob beforehand.

Reported-by: syzbot+cfc0247ac173f597aaaa@syzkaller.appspotmail.com
Reported-by: Andy Nguyen <theflow@google.com>
Fixes: 9fa492cdc160c ("[NETFILTER]: x_tables: simplify compat API")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-16 11:49:31 +02:00
Alexander Ovechkin
f9501b8da4 tcp: relookup sock for RST+ACK packets handled by obsolete req sock
commit 7233da86697efef41288f8b713c10c2499cffe85 upstream.

Currently tcp_check_req can be called with obsolete req socket for which big
socket have been already created (because of CPU race or early demux
assigning req socket to multiple packets in gro batch).

Commit e0f9759f530bf789e984 ("tcp: try to keep packet if SYN_RCV race
is lost") added retry in case when tcp_check_req is called for PSH|ACK packet.
But if client sends RST+ACK immediatly after connection being
established (it is performing healthcheck, for example) retry does not
occur. In that case tcp_check_req tries to close req socket,
leaving big socket active.

Fixes: e0f9759f530b ("tcp: try to keep packet if SYN_RCV race is lost")
Signed-off-by: Alexander Ovechkin <ovov@yandex-team.ru>
Reported-by: Oleg Senin <olegsenin@yandex-team.ru>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-07 12:48:47 +02:00
Mark Tomlinson
74bc0e5132 Revert "netfilter: x_tables: Update remaining dereference to RCU"
[ Upstream commit abe7034b9a8d57737e80cc16d60ed3666990bdbf ]

This reverts commit 443d6e86f821a165fae3fc3fc13086d27ac140b1.

This (and the following) patch basically re-implemented the RCU
mechanisms of patch 784544739a25. That patch was replaced because of the
performance problems that it created when replacing tables. Now, we have
the same issue: the call to synchronize_rcu() makes replacing tables
slower by as much as an order of magnitude.

Revert these patches and fix the issue in a different way.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:37:02 +02:00
Mark Tomlinson
0abcfaf058 Revert "netfilter: x_tables: Switch synchronization to RCU"
[ Upstream commit d3d40f237480abf3268956daf18cdc56edd32834 ]

This reverts commit cc00bcaa589914096edef7fb87ca5cee4a166b5c.

This (and the preceding) patch basically re-implemented the RCU
mechanisms of patch 784544739a25. That patch was replaced because of the
performance problems that it created when replacing tables. Now, we have
the same issue: the call to synchronize_rcu() makes replacing tables
slower by as much as an order of magnitude.

Prior to using RCU a script calling "iptables" approx. 200 times was
taking 1.16s. With RCU this increased to 11.59s.

Revert these patches and fix the issue in a different way.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:37:02 +02:00
Paul Moore
a44af1c697 cipso,calipso: resolve a number of problems with the DOI refcounts
commit ad5d07f4a9cd671233ae20983848874731102c08 upstream.

The current CIPSO and CALIPSO refcounting scheme for the DOI
definitions is a bit flawed in that we:

1. Don't correctly match gets/puts in netlbl_cipsov4_list().
2. Decrement the refcount on each attempt to remove the DOI from the
   DOI list, only removing it from the list once the refcount drops
   to zero.

This patch fixes these problems by adding the missing "puts" to
netlbl_cipsov4_list() and introduces a more conventional, i.e.
not-buggy, refcounting mechanism to the DOI definitions.  Upon the
addition of a DOI to the DOI list, it is initialized with a refcount
of one, removing a DOI from the list removes it from the list and
drops the refcount by one; "gets" and "puts" behave as expected with
respect to refcounts, increasing and decreasing the DOI's refcount by
one.

Fixes: b1edeb102397 ("netlabel: Replace protocol/NetLabel linking with refrerence counts")
Fixes: d7cce01504a0 ("netlabel: Add support for removing a CALIPSO DOI.")
Reported-by: syzbot+9ec037722d2603a9f52e@syzkaller.appspotmail.com
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 16:43:44 +01:00
Eric Dumazet
319f460237 tcp: add sanity tests to TCP_QUEUE_SEQ
[ Upstream commit 8811f4a9836e31c14ecdf79d9f3cb7c5d463265d ]

Qingyu Li reported a syzkaller bug where the repro
changes RCV SEQ _after_ restoring data in the receive queue.

mprotect(0x4aa000, 12288, PROT_READ)    = 0
mmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000
mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000
mmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000
socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3
setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0
connect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_scope_id=0}, 28) = 0
setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0
sendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="0x0000000000000003\0\0", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20
setsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0
setsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0
recvfrom(3, NULL, 20, 0, NULL, NULL)    = -1 ECONNRESET (Connection reset by peer)

syslog shows:
[  111.205099] TCP recvmsg seq # bug 2: copied 80, seq 0, rcvnxt 80, fl 0
[  111.207894] WARNING: CPU: 1 PID: 356 at net/ipv4/tcp.c:2343 tcp_recvmsg_locked+0x90e/0x29a0

This should not be allowed. TCP_QUEUE_SEQ should only be used
when queues are empty.

This patch fixes this case, and the tx path as well.

Fixes: ee9952831cfd ("tcp: Initial repair mode")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=212005
Reported-by: Qingyu Li <ieatmuttonchuan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 16:43:43 +01:00
Eric Dumazet
92ba49b27e tcp: annotate tp->write_seq lockless reads
[ Upstream commit 0f31746452e6793ad6271337438af8f4defb8940 ]

There are few places where we fetch tp->write_seq while
this field can change from IRQ or other cpu.

We need to add READ_ONCE() annotations, and also make
sure write sides use corresponding WRITE_ONCE() to avoid
store-tearing.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 16:43:43 +01:00
Eric Dumazet
7209e12096 tcp: annotate tp->copied_seq lockless reads
[ Upstream commit 7db48e983930285b765743ebd665aecf9850582b ]

There are few places where we fetch tp->copied_seq while
this field can change from IRQ or other cpu.

We need to add READ_ONCE() annotations, and also make
sure write sides use corresponding WRITE_ONCE() to avoid
store-tearing.

Note that tcp_inq_hint() was already using READ_ONCE(tp->copied_seq)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 16:43:42 +01:00