KASAN: null-ptr-deref Write in udf_bread

Status: upstream: reported C repro on 2024/04/30 17:16
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+257351b0d5fe1fb3655e@syzkaller.appspotmail.com
First crash: 887d, last: 17d
Fix commit to backport (bisect log) :
tree: upstream
commit 32f123a3f34283f9c6446de87861696f0502b02e
Author: Jan Kara <jack@suse.cz>
Date: Wed Jan 18 14:33:41 2023 +0000

  udf: Fold udf_getblk() into udf_bread()

  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2024/05/01 linux-5.15.y (ToT) b925f60c6ee7 C [report] KASAN: null-ptr-deref Write in udf_bread
2024/05/01 upstream (ToT) 18daea77cca6 C Didn't crash
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: null-ptr-deref Write in udf_bread origin:upstream missing-backport 12 syz, C done 83 659d 1133d 0/3 upstream: reported C repro on 2023/08/28 19:44
upstream KASAN: null-ptr-deref Write in udf_bread udf 12 1 1350d 1346d 0/29 auto-obsoleted due to no activity on 2023/04/23 14:58
▶ ▼ Last patch testing requests (10)
Created Duration User Patch Repo Result
2026/08/15 19:20 18m retest repro linux-5.15.y report job log log
2026/08/15 19:20 19m retest repro linux-5.15.y report job log log
2026/08/15 19:20 18m retest repro linux-5.15.y report job log log
2026/07/16 21:35 20m retest repro linux-5.15.y report log
2026/06/16 21:34 16m retest repro linux-5.15.y report log
2026/05/15 20:07 2h15m retest repro linux-5.15.y report log
2026/05/15 20:07 2h09m retest repro linux-5.15.y report log
2026/05/15 20:07 16m retest repro linux-5.15.y report log
2026/04/28 04:54 17m retest repro linux-5.15.y report log
2026/04/05 07:11 10m retest repro linux-5.15.y report log
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2024/05/13 04:56 4h28m fix candidate upstream OK (1) job log

Sample crash report:
loop0: detected capacity change from 0 to 2048
UDF-fs: INFO Mounting volume 'LiuxUDF', timestamp 2022/11/22 14:59 (1000)
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: null-ptr-deref in test_and_set_bit_lock include/asm-generic/bitops/instrumented-lock.h:55 [inline]
BUG: KASAN: null-ptr-deref in trylock_buffer include/linux/buffer_head.h:395 [inline]
BUG: KASAN: null-ptr-deref in lock_buffer include/linux/buffer_head.h:401 [inline]
BUG: KASAN: null-ptr-deref in udf_getblk fs/udf/inode.c:383 [inline]
BUG: KASAN: null-ptr-deref in udf_bread+0x2db/0x5b0 fs/udf/inode.c:1111
Write of size 8 at addr 0000000000000000 by task syz.0.17/4316

CPU: 1 PID: 4316 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 __kasan_report mm/kasan/report.c:438 [inline]
 kasan_report+0xd5/0x130 mm/kasan/report.c:451
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x235/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 test_and_set_bit_lock include/asm-generic/bitops/instrumented-lock.h:55 [inline]
 trylock_buffer include/linux/buffer_head.h:395 [inline]
 lock_buffer include/linux/buffer_head.h:401 [inline]
 udf_getblk fs/udf/inode.c:383 [inline]
 udf_bread+0x2db/0x5b0 fs/udf/inode.c:1111
 udf_fiiter_append_blk+0x354/0x870 fs/udf/directory.c:463
 udf_fiiter_add_entry+0xd5c/0x1eb0 fs/udf/namei.c:292
 udf_add_nondir+0x121/0x330 fs/udf/namei.c:346
 lookup_open fs/namei.c:3513 [inline]
 open_last_lookups fs/namei.c:3583 [inline]
 path_openat+0x120a/0x2fb0 fs/namei.c:3790
 do_filp_open+0x1df/0x400 fs/namei.c:3820
 do_sys_openat2+0x14b/0x500 fs/open.c:1255
 do_sys_open fs/open.c:1271 [inline]
 __do_sys_creat fs/open.c:1347 [inline]
 __se_sys_creat fs/open.c:1341 [inline]
 __x64_sys_creat+0x8c/0xb0 fs/open.c:1341
 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: 0033:0x7f1ce6d52159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe8253adf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f1ce6fd9fa0 RCX: 00007f1ce6d52159
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000580
RBP: 00007f1ce6de903b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1ce6fd9fac R14: 00007f1ce6fd9fa0 R15: 00007f1ce6fd9fa0
 </TASK>
==================================================================

Crashes (100):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/10 05:00 linux-5.15.y 0996e0926f6b 4e8b1cc6 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2 (corrupt fs)] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2026/01/29 21:59 linux-5.15.y 9eec9a14ee10 aeb6fdd5 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/09/12 22:49 linux-5.15.y 43bb85222e53 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2 (corrupt fs)] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/10/05 11:05 linux-5.15.y 3a5928702e71 d7906eff .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/04/30 22:43 linux-5.15.y b925f60c6ee7 3ce4924c .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/01/17 04:51 linux-5.15.y 4735586da88e f9e07a6e .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-linux-5-15-kasan-arm64 KASAN: null-ptr-deref Write in udf_bread
2026/09/17 05:32 linux-5.15.y 0248c33e835e 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2026/09/15 06:05 linux-5.15.y 0248c33e835e 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2026/09/10 04:31 linux-5.15.y 0996e0926f6b 4e8b1cc6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2026/01/29 20:40 linux-5.15.y 9eec9a14ee10 aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/10/26 07:36 linux-5.15.y ac56c046adf4 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/10/05 03:23 linux-5.15.y 29e53a5b1c4f 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/10/04 18:18 linux-5.15.y 29e53a5b1c4f 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/09/15 01:25 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/09/12 22:12 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/08/22 22:37 linux-5.15.y c79648372d02 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/08/11 15:33 linux-5.15.y c79648372d02 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/08/11 15:22 linux-5.15.y c79648372d02 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/07/22 06:40 linux-5.15.y c79648372d02 1555463b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/05/25 05:08 linux-5.15.y 98f47d0e9b8c ed351ea7 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/03/29 11:18 linux-5.15.y 0c935c049b5c cf25e2c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/03/10 08:03 linux-5.15.y c16c81c81336 163f510d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/01/17 18:13 linux-5.15.y 4735586da88e 953d1c45 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/12/28 23:09 linux-5.15.y 91786f140358 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/12/28 23:09 linux-5.15.y 91786f140358 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/12/18 03:33 linux-5.15.y 963e654022cc a0626d3a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/10/14 10:19 linux-5.15.y 3a5928702e71 084d8178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/10/09 10:28 linux-5.15.y 3a5928702e71 402f1df0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/10/07 22:04 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/10/05 10:32 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/07/19 08:43 linux-5.15.y 7c6d66f0266f ee4e11c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/07/05 22:13 linux-5.15.y f45bea23c39c 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/07/05 16:13 linux-5.15.y f45bea23c39c 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/07/03 16:55 linux-5.15.y 4878aadf2d15 1ecfa2d8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/07/01 19:20 linux-5.15.y 4878aadf2d15 b294e901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/20 01:43 linux-5.15.y 4878aadf2d15 41b7e219 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/14 03:58 linux-5.15.y c61bd26ae81a a9616ff5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/14 03:41 linux-5.15.y c61bd26ae81a a9616ff5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/14 03:41 linux-5.15.y c61bd26ae81a a9616ff5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/13 22:50 linux-5.15.y c61bd26ae81a a9616ff5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/13 22:49 linux-5.15.y c61bd26ae81a a9616ff5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/13 22:48 linux-5.15.y c61bd26ae81a a9616ff5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/13 10:45 linux-5.15.y c61bd26ae81a 2aa5052f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/13 10:44 linux-5.15.y c61bd26ae81a 2aa5052f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/12 17:49 linux-5.15.y c61bd26ae81a f815599d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/10 06:38 linux-5.15.y c61bd26ae81a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/05 10:59 linux-5.15.y c61bd26ae81a e1e2c66e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/05 06:33 linux-5.15.y c61bd26ae81a e1e2c66e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/05 06:33 linux-5.15.y c61bd26ae81a e1e2c66e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/05 06:28 linux-5.15.y c61bd26ae81a e1e2c66e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/05 06:27 linux-5.15.y c61bd26ae81a e1e2c66e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/05 05:27 linux-5.15.y c61bd26ae81a e1e2c66e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/04 04:13 linux-5.15.y c61bd26ae81a a1feae05 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/03 18:14 linux-5.15.y c61bd26ae81a 0aba2352 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/03 18:07 linux-5.15.y c61bd26ae81a 0aba2352 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/06/03 18:07 linux-5.15.y c61bd26ae81a 0aba2352 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2024/04/30 17:15 linux-5.15.y b925f60c6ee7 3ce4924c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: null-ptr-deref Write in udf_bread
2025/03/12 07:36 linux-5.15.y c16c81c81336 ee70e6db .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: null-ptr-deref Write in udf_bread
2025/02/03 18:13 linux-5.15.y c16c81c81336 a21a8419 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: null-ptr-deref Write in udf_bread
2025/02/03 03:38 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: null-ptr-deref Write in udf_bread
2025/01/17 04:19 linux-5.15.y 4735586da88e f9e07a6e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: null-ptr-deref Write in udf_bread
* Struck through repros no longer work on HEAD.