syzbot


kernel BUG in ext4_es_cache_extent (3)

Status: upstream: reported C repro on 2025/09/04 09:44
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+038b7bf43423e132b308@syzkaller.appspotmail.com
First crash: 1d04h, last: 1d03h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ext4?] kernel BUG in ext4_es_cache_extent (3) 0 (1) 2025/09/04 09:44
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel BUG in ext4_es_cache_extent ext4 -1 C inconclusive 6 947d 1306d 22/29 fixed on 2023/02/24 13:50
android-54 kernel BUG in ext4_es_cache_extent ext4 -1 C 16 413d 1103d 0/2 auto-obsoleted due to no activity on 2024/10/26 14:37
android-5-10 kernel BUG in ext4_es_cache_extent -1 C error 1 1103d 1103d 0/2 closed as invalid on 2022/09/13 19:49
upstream kernel BUG in ext4_es_cache_extent (2) ext4 -1 1 224d 220d 0/29 auto-obsoleted due to no activity on 2025/05/03 18:51

Sample crash report:
EXT4-fs (loop0): 1 truncate cleaned up
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.
------------[ cut here ]------------
kernel BUG at fs/ext4/extents_status.c:1012!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5527 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:ext4_es_cache_extent+0x698/0x700 fs/ext4/extents_status.c:1012
Code: ff df 80 3c 08 00 74 08 48 89 df e8 62 b0 b3 ff 48 8b 3b 48 8b 74 24 28 48 8d 54 24 60 e8 00 c3 0d 00 eb 14 e8 69 c0 4e ff 90 <0f> 0b e8 61 c0 4e ff eb 28 e8 5a c0 4e ff 31 f6 65 ff 0d 81 32 30
RSP: 0018:ffffc900028ff420 EFLAGS: 00010293
RAX: ffffffff8270fd97 RBX: 00000000ffffffff RCX: ffff8880330fc880
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 00000000000072ce
RBP: ffffc900028ff528 R08: ffffffff8fa3b637 R09: 1ffffffff1f476c6
R10: dffffc0000000000 R11: fffffbfff1f476c7 R12: 00000000000072d0
R13: 0000000000000008 R14: 00000000000072ce R15: dffffc0000000000
FS:  000055556eaf2500(0000) GS:ffff88808d20d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32463fff CR3: 0000000056f56000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 ext4_cache_extents fs/ext4/extents.c:544 [inline]
 ext4_find_extent+0x482/0xcc0 fs/ext4/extents.c:928
 ext4_get_verity_descriptor_location fs/ext4/verity.c:292 [inline]
 ext4_get_verity_descriptor+0x102/0x590 fs/ext4/verity.c:346
 fsverity_get_descriptor+0x8d/0x4b0 fs/verity/open.c:323
 ensure_verity_info fs/verity/open.c:363 [inline]
 __fsverity_file_open+0xd7/0x1f0 fs/verity/open.c:384
 fsverity_file_open include/linux/fsverity.h:300 [inline]
 ext4_file_open+0x32d/0xa40 fs/ext4/file.c:909
 do_dentry_open+0x953/0x13f0 fs/open.c:965
 vfs_open+0x3b/0x340 fs/open.c:1095
 do_open fs/namei.c:3887 [inline]
 path_openat+0x2ee5/0x3830 fs/namei.c:4046
 do_filp_open+0x1fa/0x410 fs/namei.c:4073
 do_sys_openat2+0x121/0x1c0 fs/open.c:1435
 do_sys_open fs/open.c:1450 [inline]
 __do_sys_openat fs/open.c:1466 [inline]
 __se_sys_openat fs/open.c:1461 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1461
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a5878ebe9
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:00007fffa6498b18 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5a589c5fa0 RCX: 00007f5a5878ebe9
RDX: 0000000000000000 RSI: 0000200000000100 RDI: ffffffffffffff9c
RBP: 00007f5a58811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5a589c5fa0 R14: 00007f5a589c5fa0 R15: 0000000000000004
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_es_cache_extent+0x698/0x700 fs/ext4/extents_status.c:1012
Code: ff df 80 3c 08 00 74 08 48 89 df e8 62 b0 b3 ff 48 8b 3b 48 8b 74 24 28 48 8d 54 24 60 e8 00 c3 0d 00 eb 14 e8 69 c0 4e ff 90 <0f> 0b e8 61 c0 4e ff eb 28 e8 5a c0 4e ff 31 f6 65 ff 0d 81 32 30
RSP: 0018:ffffc900028ff420 EFLAGS: 00010293
RAX: ffffffff8270fd97 RBX: 00000000ffffffff RCX: ffff8880330fc880
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 00000000000072ce
RBP: ffffc900028ff528 R08: ffffffff8fa3b637 R09: 1ffffffff1f476c6
R10: dffffc0000000000 R11: fffffbfff1f476c7 R12: 00000000000072d0
R13: 0000000000000008 R14: 00000000000072ce R15: dffffc0000000000
FS:  000055556eaf2500(0000) GS:ffff88808d20d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32463fff CR3: 0000000056f56000 CR4: 0000000000352ef0

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/04 00:33 upstream ec299e4dc21e 19216959 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci-snapshot-upstream-root kernel BUG in ext4_es_cache_extent
2025/09/04 00:09 upstream ec299e4dc21e 19216959 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci-snapshot-upstream-root kernel BUG in ext4_es_cache_extent
2025/09/03 23:45 upstream ec299e4dc21e 19216959 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci-snapshot-upstream-root kernel BUG in ext4_es_cache_extent
2025/09/03 23:19 upstream ec299e4dc21e 19216959 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in ext4_es_cache_extent
* Struck through repros no longer work on HEAD.