WARNING in kcm_write_msgs

Status: upstream: reported C repro on 2020/04/12 04:13
First crash: 1268d, last: 262d
Fix bisection the fix commit could be any of (bisect log):
  4520f06b03ae Linux 4.14.175
  56dfe6252c68 Linux 4.14.188
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in kcm_write_msgs net C done 353 4d13h 1292d 0/25 upstream: reported C repro on 2020/03/19 07:10
linux-4.19 WARNING in kcm_write_msgs C error 8 256d 1280d 0/1 upstream: reported C repro on 2020/03/30 19:34
Last patch testing requests (1)
Created Duration User Patch Repo Result
2022/09/07 06:27 8m retest repro linux-4.14.y report log
Fix bisection attempts (3)
Created Duration User Patch Repo Result
2020/07/11 05:32 31m bisect fix linux-4.14.y job log (2)
2020/06/11 05:08 23m bisect fix linux-4.14.y job log (0) log
2020/05/12 04:41 26m bisect fix linux-4.14.y job log (0) log

Sample crash report:
IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready
batman_adv: batadv0: Interface activated: batadv_slave_1
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
------------[ cut here ]------------
WARNING: CPU: 1 PID: 9395 at net/kcm/kcmsock.c:634 kcm_write_msgs+0x1041/0x1820 net/kcm/kcmsock.c:634
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 9395 Comm: syz-executor286 Not tainted 4.14.302-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 panic+0x1f9/0x42d kernel/panic.c:183
 __warn.cold+0x20/0x44 kernel/panic.c:547
 report_bug+0x208/0x250 lib/bug.c:183
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x195/0x2d0 arch/x86/kernel/traps.c:295
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:967
RIP: 0010:kcm_write_msgs+0x1041/0x1820 net/kcm/kcmsock.c:634
RSP: 0018:ffff8880870879f8 EFLAGS: 00010297
RAX: ffff8880a0792180 RBX: 00000000000000c0 RCX: 0000000000000007
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a2e0d842
RBP: ffff8880a2e0d840 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000008000
R13: ffff8880a1ca9c40 R14: ffff8880a2e0d780 R15: 0000000000000000
 kcm_sendmsg+0x177c/0x1e10 net/kcm/kcmsock.c:1040
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 sock_write_iter+0x22c/0x370 net/socket.c:925
 call_write_iter include/linux/fs.h:1780 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x44c/0x630 fs/read_write.c:482
 vfs_write+0x17f/0x4d0 fs/read_write.c:544
 SYSC_write fs/read_write.c:590 [inline]
 SyS_write+0xf2/0x210 fs/read_write.c:582
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
RIP: 0033:0x7f180e58ab79
RSP: 002b:00007f180e5382f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f180e6144e0 RCX: 00007f180e58ab79
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007f180e5e0c9c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f180e5e0610
R13: 0000000020000240 R14: 656c6c616b7a7973 R15: 00007f180e6144e8
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/01/13 05:48 linux-4.14.y c4215ee4771b 96166539 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-4-14 WARNING in kcm_write_msgs
2020/04/12 04:12 linux-4.14.y 4520f06b03ae a8c6a3f8 .config console log report syz C ci2-linux-4-14
* Struck through repros no longer work on HEAD.