kernel BUG in gfs2_glock_nq

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 66722c42ec91 Linux 4.14.256
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1230f33db00000
kernel config: https://syzkaller.appspot.com/x/.config?x=b8004ce84f364d9
dashboard link: https://syzkaller.appspot.com/bug?extid=0e432080099928fe31e5
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0e4320...@syzkaller.appspotmail.com

gfs2: pid: 7998
gfs2: lock type: 8 req lock state : 1
gfs2: G: s:EX n:8/1 f:qb t:EX d:EX/0 a:0 v:0 r:5 m:20
gfs2: H: s:EX f:cH e:0 p:7998 [syz-executor.0] gfs2_glock_nq_init fs/gfs2/glock.h:226 [inline]
gfs2: H: s:EX f:cH e:0 p:7998 [syz-executor.0] do_sync+0x3f0/0xba0 fs/gfs2/quota.c:893
------------[ cut here ]------------
kernel BUG at fs/gfs2/glock.c:1082!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 7998 Comm: syz-executor.0 Not tainted 4.14.256-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880a06300c0 task.stack: ffff8880b5150000
RIP: 0010:add_to_queue fs/gfs2/glock.c:1082 [inline]
RIP: 0010:gfs2_glock_nq.cold+0x279/0x2d0 fs/gfs2/glock.c:1107
RSP: 0018:ffff8880b5157a88 EFLAGS: 00010296
RAX: ffffed1016a2af32 RBX: ffff8880ab4f3d20 RCX: 1ffff110140c613d
RDX: 0000000000000000 RSI: 0000000000000005 RDI: ffffffff87c0c250
RBP: 0000000000001f3e R08: 0000000000000043 R09: 0000000000000004
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a8fd7db8
R13: ffff8880ab4f3d20 R14: 0000000000000001 R15: 0000000000000000
FS: 0000555556232400(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555556d0b708 CR3: 0000000093106000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
gfs2_glock_nq_init fs/gfs2/glock.h:228 [inline]
do_sync+0x3f8/0xba0 fs/gfs2/quota.c:893
gfs2_quota_sync+0x4f1/0x690 fs/gfs2/quota.c:1299
gfs2_sync_fs+0x40/0xa0 fs/gfs2/super.c:947
__sync_filesystem fs/sync.c:39 [inline]
sync_filesystem fs/sync.c:64 [inline]
sync_filesystem+0xe2/0x230 fs/sync.c:48
generic_shutdown_super+0x70/0x370 fs/super.c:432
kill_block_super+0x95/0xe0 fs/super.c:1161
gfs2_kill_sb+0x12c/0x1a0 fs/gfs2/ops_fstype.c:1409
deactivate_locked_super+0x6c/0xd0 fs/super.c:319
deactivate_super+0x7f/0xa0 fs/super.c:350
cleanup_mnt+0x186/0x2c0 fs/namespace.c:1183
task_work_run+0x11f/0x190 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:191 [inline]
exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164
prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f675ab9df57
RSP: 002b:00007ffcb87da128 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f675ab9df57
RDX: 00007ffcb87da1f9 RSI: 000000000000000a RDI: 00007ffcb87da1f0
RBP: 00007ffcb87da1f0 R08: 00000000ffffffff R09: 00007ffcb87d9fc0
R10: 0000555556233903 R11: 0000000000000246 R12: 00007f675abf618a
R13: 00007ffcb87db2b0 R14: 0000555556233810 R15: 00007ffcb87db2f0
Code: c1 ea 03 0f b6 04 02 84 c0 74 04 3c 03 7e 6c 8b 73 18 44 89 f2 48 c7 c7 20 a0 c0 87 e8 97 86 f9 ff 4c 89 ee 31 ff e8 8e 19 b1 fb <0f> 0b e8 e7 1d 76 fa 4c 8b 04 24 e9 ac fd ff ff 31 ed e9 14 fe
RIP: add_to_queue fs/gfs2/glock.c:1082 [inline] RSP: ffff8880b5157a88
RIP: gfs2_glock_nq.cold+0x279/0x2d0 fs/gfs2/glock.c:1107 RSP: ffff8880b5157a88
---[ end trace 293334509c6f6629 ]---


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.