syzbot


WARNING in udf_unlink

Status: upstream: reported C repro on 2025/08/09 20:19
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+e933fbe57125a64776cd@syzkaller.appspotmail.com
First crash: 160d, last: 3d04h
Bug presence (1)
Date Name Commit Repro Result
2025/08/30 upstream (ToT) 11e7861d680c C [report] KASAN: use-after-free Read in udf_unlink
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in udf_unlink udf -1 1 988d 984d 0/29 auto-obsoleted due to no activity on 2023/08/23 09:03
Fix bisection attempts (3)
Created Duration User Patch Repo Result
2025/11/23 00:49 1h45m bisect fix linux-6.6.y OK (0) job log log
2025/10/23 12:20 1h39m bisect fix linux-6.6.y OK (0) job log log
2025/09/16 11:41 1h41m bisect fix linux-6.6.y OK (0) job log log

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5880 at fs/udf/udfdecl.h:123 udf_updated_lvid fs/udf/udfdecl.h:121 [inline]
WARNING: CPU: 1 PID: 5880 at fs/udf/udfdecl.h:123 udf_add_fid_counter fs/udf/namei.c:346 [inline]
WARNING: CPU: 1 PID: 5880 at fs/udf/udfdecl.h:123 udf_unlink+0x5a1/0x6d0 fs/udf/namei.c:565
Modules linked in:
CPU: 1 PID: 5880 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:udf_updated_lvid fs/udf/udfdecl.h:121 [inline]
RIP: 0010:udf_add_fid_counter fs/udf/namei.c:346 [inline]
RIP: 0010:udf_unlink+0x5a1/0x6d0 fs/udf/namei.c:565
Code: 00 65 48 8b 04 25 28 00 00 00 48 3b 84 24 40 01 00 00 75 1d 89 d8 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 0f 00 8f fe <0f> 0b e9 a3 fe ff ff e8 53 5b 71 07 44 89 f1 80 e1 07 80 c1 03 38
RSP: 0018:ffffc90003367be0 EFLAGS: 00010293
RAX: ffffffff82f6aaf1 RBX: 0000000055555555 RCX: ffff88802d1d9e00
RDX: 0000000000000000 RSI: 0000000055555555 RDI: 0000000000000000
RBP: ffffc90003367d80 R08: ffffffff8e4a39ef R09: 1ffffffff1c9473d
R10: dffffc0000000000 R11: fffffbfff1c9473e R12: ffff888076db4630
R13: ffff88805dd3a01f R14: 1ffff1100edb68c6 R15: dffffc0000000000
FS:  0000555567f7f500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555567faa648 CR3: 0000000030999000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 vfs_unlink+0x389/0x600 fs/namei.c:4333
 do_unlinkat+0x328/0x570 fs/namei.c:4399
 __do_sys_unlink fs/namei.c:4447 [inline]
 __se_sys_unlink fs/namei.c:4445 [inline]
 __x64_sys_unlink+0x49/0x50 fs/namei.c:4445
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe3fa38ecf7
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 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:00007ffc2e28e9c8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe3fa38ecf7
RDX: 00007ffc2e28e9f0 RSI: 00007ffc2e28ea80 RDI: 00007ffc2e28ea80
RBP: 00007ffc2e28ea80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffc2e28fb70
R13: 00007fe3fa413d7d R14: 000000000001c7f6 R15: 00007ffc2e291d30
 </TASK>

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/14 06:24 linux-6.6.y c596736dadab d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2 (clean fs)] ci2-linux-6-6-kasan WARNING in udf_unlink
2026/01/14 05:01 linux-6.6.y c596736dadab d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2 (clean fs)] ci2-linux-6-6-kasan WARNING in udf_unlink
2026/01/14 00:09 linux-6.6.y c596736dadab d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2 (clean fs)] ci2-linux-6-6-kasan WARNING in udf_unlink
2026/01/13 22:31 linux-6.6.y c596736dadab d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2 (clean fs)] ci2-linux-6-6-kasan WARNING in udf_unlink
2026/01/13 21:02 linux-6.6.y c596736dadab d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2 (clean fs)] ci2-linux-6-6-kasan WARNING in udf_unlink
2025/12/26 21:55 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan WARNING in udf_unlink
2025/12/22 09:16 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-linux-6-6-kasan WARNING in udf_unlink
2025/12/22 07:22 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-linux-6-6-kasan WARNING in udf_unlink
2025/08/09 20:18 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2] ci2-linux-6-6-kasan WARNING in udf_unlink
2026/01/11 08:44 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in udf_unlink
2026/01/11 08:44 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in udf_unlink
2026/01/11 08:42 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in udf_unlink
2026/01/11 08:41 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in udf_unlink
* Struck through repros no longer work on HEAD.