Subject: WARNING in sk_msg_check_to_free

From: syzbot <[email-masked]>
Date: Fri, 23 Aug 2019 07:33:06 -0700

Hello,

syzbot found the following crash on:

HEAD commit:    fed07ef3 Merge tag 'mlx5-updates-2019-08-21' of git://git...
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=150102bc600000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e34a4fe936eac597
dashboard link: https://syzkaller.appspot.com/bug?extid=ea3c54a7b2364123d818
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email-masked]

------------[ cut here ]------------
WARNING: CPU: 0 PID: 14478 at include/linux/skmsg.h:129  
sk_msg_check_to_free.isra.0.part.0+0x15/0x19 include/linux/skmsg.h:129
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 14478 Comm: syz-executor.0 Not tainted 5.3.0-rc5+ #143
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x172/0x1f0 lib/dump_stack.c:113
  panic+0x2dc/0x755 kernel/panic.c:219
  __warn.cold+0x20/0x4c kernel/panic.c:576
  report_bug+0x263/0x2b0 lib/bug.c:186
  fixup_bug arch/x86/kernel/traps.c:179 [inline]
  fixup_bug arch/x86/kernel/traps.c:174 [inline]
  do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
  do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
  invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
RIP: 0010:sk_msg_check_to_free.isra.0.part.0+0x15/0x19  
include/linux/skmsg.h:129
Code: 77 ff ff ff e8 4e de 03 fc eb 96 4c 89 f7 e8 e4 dd 03 fc eb c3 55 48  
89 e5 e8 f9 b4 c9 fb 48 c7 c7 80 3a 48 88 e8 c1 55 b3 fb <0f> 0b 5d c3 e8  
e4 b4 c9 fb e8 dd ff ff ff 48 8b 45 d0 0f b6 00 41
RSP: 0018:ffff88806381fb98 EFLAGS: 00010286
RAX: 0000000000000024 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815c2456 RDI: ffffed100c703f65
RBP: ffff88806381fb98 R08: 0000000000000024 R09: ffffed1015d060d1
R10: ffffed1015d060d0 R11: ffff8880ae830687 R12: 000000000000000d
R13: ffff8880986c1550 R14: 0000000000000001 R15: 0000000000000007
  sk_msg_check_to_free include/linux/skmsg.h:129 [inline]
  __sk_msg_free.cold+0xa/0x2e net/core/skmsg.c:190
  sk_msg_free+0x44/0x60 net/core/skmsg.c:207
  tls_sw_release_resources_tx+0x268/0x6b0 net/tls/tls_sw.c:2092
  tls_sk_proto_cleanup net/tls/tls_main.c:275 [inline]
  tls_sk_proto_close+0x6a7/0x990 net/tls/tls_main.c:305
  inet_release+0xed/0x200 net/ipv4/af_inet.c:427
  inet6_release+0x53/0x80 net/ipv6/af_inet6.c:470
  __sock_release+0xce/0x280 net/socket.c:590
  sock_close+0x1e/0x30 net/socket.c:1268
  __fput+0x2ff/0x890 fs/file_table.c:280
  ____fput+0x16/0x20 fs/file_table.c:313
  task_work_run+0x145/0x1c0 kernel/task_work.c:113
  tracehook_notify_resume include/linux/tracehook.h:188 [inline]
  exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:163
  prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
  syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
  do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:299
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x413511
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48  
83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48  
89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007ffdca8135c0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000413511
RDX: 0000001b31920000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000025038832 R09: 0000000025038836
R10: 00007ffdca8136a0 R11: 0000000000000293 R12: 000000000075bf20
R13: 000000000009f412 R14: 0000000000760b20 R15: ffffffffffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..

---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at [email-masked].

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.