bisecting fixing commit since 31acccdc877486a649a86d37725a15175fcd5ed6
building syzkaller on cca8798699baeeccbf80af23d234ac19a5d667aa
testing commit 31acccdc877486a649a86d37725a15175fcd5ed6 with gcc (GCC) 8.4.1 20210217
kernel signature: cf7d4e1f79d8a0b7499e4ac105af080657bca848f0a08574c932029a8b6b1e6f
all runs: crashed: kernel BUG in dnotify_free_mark
testing current HEAD 255b58a2b3af0baa0ee11507390349217b8b73b0
testing commit 255b58a2b3af0baa0ee11507390349217b8b73b0 with gcc (GCC) 8.4.1 20210217
kernel signature: e5d61557f5109f21d30265745b7726f03bbebf2d77ab7632a86f0db44c95f26a
all runs: crashed: kernel BUG in dnotify_free_mark
revisions tested: 2, total time: 22m18.804819816s (build: 14m50.095335995s, test: 6m33.891831488s)
the crash still happens on HEAD
commit msg: Linux 4.19.176
crash: kernel BUG in dnotify_free_mark
wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
------------[ cut here ]------------
kernel BUG at fs/notify/dnotify/dnotify.c:132!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 9175 Comm: kworker/u4:7 Not tainted 4.19.176-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound fsnotify_mark_destroy_workfn
RIP: 0010:dnotify_free_mark fs/notify/dnotify/dnotify.c:132 [inline]
RIP: 0010:dnotify_free_mark+0x3b/0x50 fs/notify/dnotify/dnotify.c:126
Code: 78 48 89 fa 48 89 e5 48 83 ec 08 48 c1 ea 03 80 3c 02 00 75 17 48 83 7e 78 00 75 0e 48 8b 3d 34 a4 15 09 e8 17 23 e7 ff c9 c3 <0f> 0b 48 89 75 f8 e8 4a 5c e7 ff 48 8b 75 f8 eb da 0f 1f 40 00 55
RSP: 0018:ffff8881cfa27c68 EFLAGS: 00010282
RAX: dffffc0000000000 RBX: ffff8881ef22d840 RCX: 1ffff1103a2a536b
RDX: 1ffff1103a2a5377 RSI: ffff8881d1529b40 RDI: ffff8881d1529bb8
RBP: ffff8881cfa27c70 R08: ffff8881cfa27cf0 R09: 1ffff11039f44f9f
R10: ffffed103eca4552 R11: ffff8881f6522a93 R12: ffff8881d1529b40
R13: ffffffff88142980 R14: dffffc0000000000 R15: ffff8881d1529b40
FS:  0000000000000000(0000) GS:ffff8881f6500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d9184d6ca8 CR3: 000000000986d004 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 fsnotify_final_mark_destroy+0x6d/0xa0 fs/notify/mark.c:213
 fsnotify_mark_destroy_workfn+0x1d7/0x390 fs/notify/mark.c:799
 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2152
 worker_thread+0x85/0xb60 kernel/workqueue.c:2295
 kthread+0x347/0x410 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Modules linked in:
---[ end trace e762f612d20f946b ]---
RIP: 0010:dnotify_free_mark fs/notify/dnotify/dnotify.c:132 [inline]
RIP: 0010:dnotify_free_mark+0x3b/0x50 fs/notify/dnotify/dnotify.c:126
Code: 78 48 89 fa 48 89 e5 48 83 ec 08 48 c1 ea 03 80 3c 02 00 75 17 48 83 7e 78 00 75 0e 48 8b 3d 34 a4 15 09 e8 17 23 e7 ff c9 c3 <0f> 0b 48 89 75 f8 e8 4a 5c e7 ff 48 8b 75 f8 eb da 0f 1f 40 00 55
RSP: 0018:ffff8881cfa27c68 EFLAGS: 00010282
RAX: dffffc0000000000 RBX: ffff8881ef22d840 RCX: 1ffff1103a2a536b
RDX: 1ffff1103a2a5377 RSI: ffff8881d1529b40 RDI: ffff8881d1529bb8
RBP: ffff8881cfa27c70 R08: ffff8881cfa27cf0 R09: 1ffff11039f44f9f
R10: ffffed103eca4552 R11: ffff8881f6522a93 R12: ffff8881d1529b40
R13: ffffffff88142980 R14: dffffc0000000000 R15: ffff8881d1529b40
FS:  0000000000000000(0000) GS:ffff8881f6500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d9184d6ca8 CR3: 000000000986d004 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400