WARNING in fanotify_handle_event

Status: upstream: reported C repro on 2025/07/08 09:14
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+9e2f62dad852da4b197b@syzkaller.appspotmail.com
First crash: 384d, last: 36d
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2025/07/09 upstream (ToT) 733923397fd9 C [report] WARNING in fanotify_handle_event
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 WARNING in fanotify_handle_event origin:upstream -1 C error 3 57d 328d 0/2 upstream: reported C repro on 2025/09/02 05:01
upstream WARNING in fanotify_handle_event (2) exfat -1 C error 31 32d 622d 0/29 upstream: reported C repro on 2024/11/12 04:21
linux-6.1 WARNING in fanotify_handle_event origin:upstream -1 C error 5 213d 384d 0/3 upstream: reported C repro on 2025/07/08 10:20
upstream WARNING in fanotify_handle_event fs -1 C done 5 2597d 2595d 12/29 fixed on 2019/07/10 21:40
▶ ▼ Last patch testing requests (10)
Created Duration User Patch Repo Result
2026/06/21 01:50 17m retest repro linux-5.15.y report log
2026/06/21 01:50 16m retest repro linux-5.15.y report log
2026/05/22 08:49 1h33m retest repro linux-5.15.y report log
2026/04/11 19:36 10m retest repro linux-5.15.y report log
2026/03/27 01:40 14m retest repro linux-5.15.y report log
2026/03/12 15:50 10m retest repro linux-5.15.y report log
2026/01/01 15:38 9m retest repro linux-5.15.y report log
2026/01/01 15:38 10m retest repro linux-5.15.y report log
2025/11/11 22:41 11m retest repro linux-5.15.y report log
2025/10/07 04:16 9m retest repro linux-5.15.y report log
▶ ▼ Fix bisection attempts (3)
Created Duration User Patch Repo Result
2026/01/31 16:52 0m bisect fix linux-5.15.y error job log
2025/12/16 03:14 1h39m bisect fix linux-5.15.y OK (0) job log log
2025/09/02 14:58 2h08m bisect fix linux-5.15.y OK (0) job log log

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4443 at fs/notify/fanotify/fanotify.h:216 fanotify_info_copy_name fs/notify/fanotify/fanotify.h:216 [inline]
WARNING: CPU: 1 PID: 4443 at fs/notify/fanotify/fanotify.h:216 fanotify_alloc_name_event fs/notify/fanotify/fanotify.c:646 [inline]
WARNING: CPU: 1 PID: 4443 at fs/notify/fanotify/fanotify.h:216 fanotify_alloc_event fs/notify/fanotify/fanotify.c:810 [inline]
WARNING: CPU: 1 PID: 4443 at fs/notify/fanotify/fanotify.h:216 fanotify_handle_event+0x237d/0x36a0 fs/notify/fanotify/fanotify.c:948
Modules linked in:
CPU: 1 PID: 4443 Comm: syz.0.16 Not tainted 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:fanotify_info_copy_name fs/notify/fanotify/fanotify.h:216 [inline]
RIP: 0010:fanotify_alloc_name_event fs/notify/fanotify/fanotify.c:646 [inline]
RIP: 0010:fanotify_alloc_event fs/notify/fanotify/fanotify.c:810 [inline]
RIP: 0010:fanotify_handle_event+0x237d/0x36a0 fs/notify/fanotify/fanotify.c:948
Code: ae dd ff ff e8 74 f5 9d ff 0f 0b eb 79 e8 6b f5 9d ff 0f 0b e9 b2 fa ff ff e8 5f f5 9d ff 0f 0b e9 e6 fb ff ff e8 53 f5 9d ff <0f> 0b e9 47 fd ff ff e8 47 f5 9d ff 0f 0b e9 cd fe ff ff e8 3b f5
RSP: 0018:ffffc9000335f780 EFLAGS: 00010293
RAX: ffffffff81d9cdbd RBX: 0000000000000ffd RCX: ffff88807b3a1dc0
RDX: 0000000000000000 RSI: 0000000000000ffd RDI: 00000000000000ff
RBP: ffffc9000335f960 R08: ffff88807b3a1dc0 R09: 0000000000000002
R10: 00000000000000ff R11: 0000000000000000 R12: ffff888077d18000
R13: ffff888077d18000 R14: dffffc0000000000 R15: 0000000000000000
FS:  0000555568c22500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005615ee610950 CR3: 0000000020a3b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 send_to_group fs/notify/fsnotify.c:374 [inline]
 fsnotify+0x10d6/0x1ca0 fs/notify/fsnotify.c:584
 __fsnotify_parent+0x5ae/0x6e0 fs/notify/fsnotify.c:241
 fsnotify_parent include/linux/fsnotify.h:77 [inline]
 fsnotify_file include/linux/fsnotify.h:105 [inline]
 fsnotify_open include/linux/fsnotify.h:336 [inline]
 do_open_execat+0x5da/0x740 fs/exec.c:937
 bprm_execve+0x511/0x17d0 fs/exec.c:1827
 do_execveat_common+0x51e/0x6d0 fs/exec.c:1957
 do_execve fs/exec.c:2027 [inline]
 __do_sys_execve fs/exec.c:2103 [inline]
 __se_sys_execve fs/exec.c:2098 [inline]
 __x64_sys_execve+0x8e/0xa0 fs/exec.c:2098
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f910dddd929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe4ccd3438 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 00007f910e004fa0 RCX: 00007f910dddd929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000440
RBP: 00007f910de5fb39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f910e004fa0 R14: 00007f910e004fa0 R15: 0000000000000003
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/08 11:02 linux-5.15.y 3dea0e7f549e 4f67c4ae .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan WARNING in fanotify_handle_event
2025/07/08 10:29 linux-5.15.y 3dea0e7f549e 4f67c4ae .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan WARNING in fanotify_handle_event
2025/07/08 09:51 linux-5.15.y 3dea0e7f549e 4f67c4ae .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan WARNING in fanotify_handle_event
2025/07/08 09:13 linux-5.15.y 3dea0e7f549e 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in fanotify_handle_event
* Struck through repros no longer work on HEAD.