general protection fault in detach_if_pending

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: db189223 Linux 4.14.147
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13f2aafd600000
kernel config: https://syzkaller.appspot.com/x/.config?x=14d726467704dd7
dashboard link: https://syzkaller.appspot.com/bug?extid=35435e99f62fd3732ac4
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: syzbot+35435e...@syzkaller.appspotmail.com

EXT4-fs (loop5): ext4_check_descriptors: Inode bitmap for group 0 overlaps
superblock
EXT4-fs (loop5): ext4_check_descriptors: Inode bitmap for group 0 not in
group (block 0)!
kasan: CONFIG_KASAN_INLINE enabled
EXT4-fs (loop5): group descriptors corrupted!
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 5 Comm: kworker/u4:0 Not tainted 4.14.147 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: tipc_send tipc_send_work
task: ffff8880a9cc2140 task.stack: ffff8880a9cd0000
RIP: 0010:__write_once_size include/linux/compiler.h:210 [inline]
RIP: 0010:__hlist_del include/linux/list.h:679 [inline]
RIP: 0010:detach_timer kernel/time/timer.c:791 [inline]
RIP: 0010:detach_if_pending+0x113/0x4a0 kernel/time/timer.c:808
RSP: 0018:ffff8880a9cd7aa8 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: ffff8880a0684e18 RCX: ffff8880a9cc29c0
RDX: 0000000000000000 RSI: ffffffff8778f720 RDI: 0000000000000086
RBP: ffff8880a9cd7ad8 R08: ffff8880a9cc2140 R09: 0000000000000004
R10: 0000000000000000 R11: ffff8880a9cc2140 R12: 0000000100000001
R13: 0000000000000001 R14: ffff8880a0684e20 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdc5fd756d4 CR3: 000000007b7c0000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
del_timer kernel/time/timer.c:1154 [inline]
del_timer+0xa9/0xf0 kernel/time/timer.c:1144
tipc_subscrb_subscrp_delete+0x16a/0x3a0 net/tipc/subscr.c:207
tipc_subscrb_delete net/tipc/subscr.c:238 [inline]
tipc_subscrb_release_cb+0x18/0x30 net/tipc/subscr.c:316
tipc_close_conn+0x176/0x210 net/tipc/server.c:203
tipc_send_to_sock net/tipc/server.c:538 [inline]
tipc_send_work+0x470/0x5a0 net/tipc/server.c:564
process_one_work+0x863/0x1600 kernel/workqueue.c:2114
worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248
kthread+0x319/0x430 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Code: ff df 4c 89 f2 4c 8b 23 48 c1 ea 03 80 3c 02 00 0f 85 6f 03 00 00 48
b8 00 00 00 00 00 fc ff df 4c 8b 7b 08 4c 89 fa 48 c1 ea 03 <80> 3c 02 00
0f 85 29 03 00 00 4d 85 e4 4d 89 27 74 2a e8 06 5f
RIP: __write_once_size include/linux/compiler.h:210 [inline] RSP:
ffff8880a9cd7aa8
RIP: __hlist_del include/linux/list.h:679 [inline] RSP: ffff8880a9cd7aa8
RIP: detach_timer kernel/time/timer.c:791 [inline] RSP: ffff8880a9cd7aa8
RIP: detach_if_pending+0x113/0x4a0 kernel/time/timer.c:808 RSP:
ffff8880a9cd7aa8

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[syzbot]

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