bisecting fixing commit since 2b79150141611d3c6e1b55d4e70f49602482f0b8
building syzkaller on 18e33098d58c8738cc3b678346141b74d34d4e30
testing commit 2b79150141611d3c6e1b55d4e70f49602482f0b8 with gcc (GCC) 8.4.1 20210217
kernel signature: 00fe5c0eb70886b7c9515f865bfe1a326212c1d4941a4efb362b27d01b78eb81
all runs: crashed: kernel BUG in dnotify_free_mark
testing current HEAD 670d6552eda8ff0c5f396d3d6f0174237917c66c
testing commit 670d6552eda8ff0c5f396d3d6f0174237917c66c with gcc (GCC) 8.4.1 20210217
kernel signature: 2dd16d60e68d0cbe5af6778940025712edd19a04cd029808ddb4f60275299dc8
all runs: crashed: kernel BUG in dnotify_free_mark
revisions tested: 2, total time: 21m15.402632689s (build: 14m31.232840209s, test: 6m22.48730114s)
the crash still happens on HEAD
commit msg: Linux 4.14.227
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
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
------------[ cut here ]------------
kernel BUG at fs/notify/dnotify/dnotify.c:131!
IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 2870 Comm: kworker/u4:4 Not tainted 4.14.227-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound fsnotify_mark_destroy_workfn
task: ffff8881e8e163c0 task.stack: ffff8881e8e28000
ieee80211 phy14: mac80211_hwsim_bss_info_changed(changed=0x10 vif->addr=02:00:00:00:0e:00)
RIP: 0010:dnotify_free_mark fs/notify/dnotify/dnotify.c:131 [inline]
RIP: 0010:dnotify_free_mark+0x3b/0x50 fs/notify/dnotify/dnotify.c:125
RSP: 0018:ffff8881e8e2fc70 EFLAGS: 00010282
RAX: dffffc0000000000 RBX: ffff8881ef1e0840 RCX: 1ffff1103d9ae93b
RDX: 1ffff1103d9ae947 RSI: ffff8881ecd749c0 RDI: ffff8881ecd74a38
RBP: ffff8881e8e2fc78 R08: ffff8881ecd74b50 R09: 1ffff1103d9ae96b
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881ecd749c0
R13: ffffffff87938860 R14: dffffc0000000000 R15: ffff8881ecd749c0
FS:  0000000000000000(0000) GS:ffff8881f6400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
ieee80211 phy14:   HT: op_mode=0xb
CR2: 00007fbe0b01c000 CR3: 0000000008e6a003 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 fsnotify_final_mark_destroy+0x72/0xa0 fs/notify/mark.c:192
 fsnotify_mark_destroy_workfn+0x1cf/0x370 fs/notify/mark.c:761
wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
 process_one_work+0x74f/0x1620 kernel/workqueue.c:2116
ieee80211 phy15: Selected rate control algorithm 'minstrel_ht'
 worker_thread+0xcc/0xee0 kernel/workqueue.c:2250
wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
 kthread+0x338/0x400 kernel/kthread.c:232
ieee80211 phy14: mac80211_hwsim_config (freq=2412(2412 - 0)/noht idle=0 ps=0 smps=static)
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Code: 
ieee80211 phy15: hwaddr 02:00:00:00:0f:00 registered
c7 78 48 89 fa 48 89 e5 48 
ieee80211 phy14: mac80211_hwsim_config (freq=2412(2412 - 0)/noht idle=0 ps=0 smps=static)
83 ec 08 48 c1 ea 03 80 3c 02 00 75 17 48 83 7e 78 00 75 0e 48 8b 3d 64 a4 74 08 e8 67 a0 e9 ff c9 c3 <0f> 0b 48 89 75 f8 e8 4a d6 e9 ff 48 8b 75 f8 eb da 0f 1f 40 00 
RIP: dnotify_free_mark fs/notify/dnotify/dnotify.c:131 [inline] RSP: ffff8881e8e2fc70
RIP: dnotify_free_mark+0x3b/0x50 fs/notify/dnotify/dnotify.c:125 RSP: ffff8881e8e2fc70
---[ end trace 2d11a25959f0e123 ]---
ieee80211 phy15: mac80211_hwsim_start