bisecting fixing commit since 31acccdc877486a649a86d37725a15175fcd5ed6
building syzkaller on cca8798699baeeccbf80af23d234ac19a5d667aa
testing commit 31acccdc877486a649a86d37725a15175fcd5ed6 with gcc (GCC) 8.4.1 20210217
kernel signature: 04904ee1b2c291590c9feed8b82cd3b0f88256958331836aaed99a39af34d2fc
all runs: crashed: kernel BUG in dnotify_free_mark
testing current HEAD 125222814e7b8f84df767d6ab622aff2a6d2f234
testing commit 125222814e7b8f84df767d6ab622aff2a6d2f234 with gcc (GCC) 8.4.1 20210217
kernel signature: 8c24499afd058259db289ff5d6079b0e4353f969dafbad0d9c2062014ea0b80d
all runs: crashed: kernel BUG in dnotify_free_mark
revisions tested: 2, total time: 22m13.465926243s (build: 15m5.889096045s, test: 6m43.609844624s)
the crash still happens on HEAD
commit msg: Linux 4.19.182
crash: kernel BUG in dnotify_free_mark
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
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: 178 Comm: kworker/u4:3 Not tainted 4.19.182-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 94 a4 15 09 e8 97 23 e7 ff c9 c3 <0f> 0b 48 89 75 f8 e8 ca 5c e7 ff 48 8b 75 f8 eb da 0f 1f 40 00 55
RSP: 0018:ffff8881f4aafc68 EFLAGS: 00010282
RAX: dffffc0000000000 RBX: ffff8881ef3bfc80 RCX: 1ffff1103cfe136b
RDX: 1ffff1103cfe1377 RSI: ffff8881e7f09b40 RDI: ffff8881e7f09bb8
RBP: ffff8881f4aafc70 R08: ffff8881f4aafcf0 R09: 1ffff1103e955f9f
R10: ffffed103eca4552 R11: ffff8881f6522a93 R12: ffff8881e7f09b40
R13: ffffffff88142b00 R14: dffffc0000000000 R15: ffff8881e7f09b40
FS:  0000000000000000(0000) GS:ffff8881f6500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fea0f8c7028 CR3: 000000000986d005 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 5590007f7995f084 ]---
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 94 a4 15 09 e8 97 23 e7 ff c9 c3 <0f> 0b 48 89 75 f8 e8 ca 5c e7 ff 48 8b 75 f8 eb da 0f 1f 40 00 55
RSP: 0018:ffff8881f4aafc68 EFLAGS: 00010282
RAX: dffffc0000000000 RBX: ffff8881ef3bfc80 RCX: 1ffff1103cfe136b
RDX: 1ffff1103cfe1377 RSI: ffff8881e7f09b40 RDI: ffff8881e7f09bb8
RBP: ffff8881f4aafc70 R08: ffff8881f4aafcf0 R09: 1ffff1103e955f9f
R10: ffffed103eca4552 R11: ffff8881f6522a93 R12: ffff8881e7f09b40
R13: ffffffff88142b00 R14: dffffc0000000000 R15: ffff8881e7f09b40
FS:  0000000000000000(0000) GS:ffff8881f6400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8ebb1d4000 CR3: 000000000986d005 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400