syzbot


WARNING: suspicious RCU usage in tcp_disconnect

Status: fixed on 2021/03/10 01:48
Subsystems: net
[Documentation on labels]
Fix commit: 13a9499e8333 mptcp: fix locking in mptcp_disconnect()
First crash: 1229d, last: 1228d
Cause bisection: introduced by (bisect log) :
commit 76e2a55d16259b51116767b28b19d759bff43f72
Author: Paolo Abeni <pabeni@redhat.com>
Date: Tue Jan 12 17:25:24 2021 +0000

  mptcp: better msk-level shutdown.

Crash: WARNING: suspicious RCU usage in tcp_disconnect (log)
Repro: C syz .config
  
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 WARNING: suspicious RCU usage in tcp_disconnect C 1309 456d 1846d 0/1 upstream: reported C repro on 2019/05/07 08:03

Sample crash report:
=============================
WARNING: suspicious RCU usage
5.11.0-rc2-syzkaller #0 Not tainted
-----------------------------
include/net/sock.h:1974 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor192/8485:
 #0: ffff888017a98120 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1594 [inline]
 #0: ffff888017a98120 (sk_lock-AF_INET6){+.+.}-{0:0}, at: inet_shutdown+0x7d/0x430 net/ipv4/af_inet.c:871

stack backtrace:
CPU: 1 PID: 8485 Comm: syz-executor192 Not tainted 5.11.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 __sk_dst_set include/net/sock.h:1974 [inline]
 __sk_dst_reset include/net/sock.h:1994 [inline]
 tcp_disconnect+0x19b7/0x1e80 net/ipv4/tcp.c:2963
 mptcp_disconnect+0xb4/0x2b0 net/mptcp/protocol.c:2650
 inet_shutdown+0x260/0x430 net/ipv4/af_inet.c:901
 __sys_shutdown_sock net/socket.c:2184 [inline]
 __sys_shutdown_sock net/socket.c:2178 [inline]
 __sys_shutdown+0xf1/0x1b0 net/socket.c:2196
 __do_sys_shutdown net/socket.c:2204 [inline]
 __se_sys_shutdown net/socket.c:2202 [inline]
 __x64_sys_shutdown+0x50/0x70 net/socket.c:2202
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x440289
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffceae0ea38 EFLAGS: 00000246 ORIG_RAX: 0000000000000030
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440289
RDX: 0000000000440289 RSI: 0000000000000000 RDI: 0000000000000003

Crashes (25):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/01/13 13:59 net-old c8a8ead01736 a945f0a3 .config console log report syz C ci-upstream-net-this-kasan-gce
2021/01/14 23:51 net-old 5b55299eed78 65a7a854 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/14 16:56 net-old 5b55299eed78 65a7a854 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/14 16:01 net-old 5b55299eed78 65a7a854 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/14 06:03 net-old a95d25dd7b94 269d24e8 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/14 00:57 net-old a95d25dd7b94 269d24e8 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/14 00:48 net-old a95d25dd7b94 269d24e8 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/14 00:12 net-old a95d25dd7b94 269d24e8 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/13 11:34 net-old c8a8ead01736 a945f0a3 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/13 11:29 net-old c8a8ead01736 a945f0a3 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/13 11:27 net-old c8a8ead01736 a945f0a3 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/13 11:15 net-old c8a8ead01736 a945f0a3 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/13 10:48 net-old c8a8ead01736 a945f0a3 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/13 07:48 net-old c8a8ead01736 0cdd6185 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/13 07:43 net-old c8a8ead01736 0cdd6185 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/13 07:36 net-old c8a8ead01736 0cdd6185 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/13 07:03 net-old c8a8ead01736 0cdd6185 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/13 06:55 net-old c8a8ead01736 0cdd6185 .config console log report info ci-upstream-net-this-kasan-gce
2021/01/14 23:13 linux-next 9152a993930d 65a7a854 .config console log report info ci-upstream-linux-next-kasan-gce-root
2021/01/14 20:16 linux-next 9152a993930d 65a7a854 .config console log report info ci-upstream-linux-next-kasan-gce-root
2021/01/14 18:17 linux-next 9152a993930d 65a7a854 .config console log report info ci-upstream-linux-next-kasan-gce-root
2021/01/14 17:52 linux-next 9152a993930d 65a7a854 .config console log report info ci-upstream-linux-next-kasan-gce-root
2021/01/14 12:01 linux-next 9152a993930d 269d24e8 .config console log report info ci-upstream-linux-next-kasan-gce-root
2021/01/14 09:47 linux-next 9152a993930d 269d24e8 .config console log report info ci-upstream-linux-next-kasan-gce-root
2021/01/14 07:59 linux-next 9152a993930d 269d24e8 .config console log report info ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.