syzbot


kernel BUG in reiserfs_cut_from_item

Status: upstream: reported C repro on 2025/11/10 10:30
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+1f1de1ece363892cc61a@syzkaller.appspotmail.com
First crash: 17d, last: 15d
Bug presence (2)
Date Name Commit Repro Result
2025/11/12 linux-6.6.y (ToT) 0a805b6ea8cd C [report] kernel BUG in reiserfs_cut_from_item
2025/11/12 upstream (ToT) 24172e0d7990 C Didn't crash
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 kernel BUG in reiserfs_cut_from_item missing-backport origin:upstream -1 C done 73 8d10h 901d 0/3 upstream: reported C repro on 2023/06/09 13:59
linux-6.1 kernel BUG in reiserfs_cut_from_item origin:upstream missing-backport -1 C done 37 268d 925d 0/3 upstream: reported C repro on 2023/05/17 06:05
upstream kernel BUG in reiserfs_cut_from_item fs -1 C error done 57 689d 1055d 0/29 auto-obsoleted due to no activity on 2024/04/16 05:18

Sample crash report:
| 0| *3.6* [2 5 0x0 SD], item_len 44, item_location 4052, free_space(entry_count) 65535 |
	mode | size | nlinks | first direct | mtime
	0100000 |      4 |  1 | 0 | 1762775627
===================================================================
REISERFS panic (device loop0): PAP-5580 reiserfs_cut_from_item: item to convert does not exist ([2 5 0x1 IND])
------------[ cut here ]------------
kernel BUG at fs/reiserfs/prints.c:390!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 5953 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__reiserfs_panic+0x13e/0x140 fs/reiserfs/prints.c:390
Code: c7 c1 00 82 bc 8a 48 0f 44 c8 4c 0f 44 f0 48 c7 c7 c0 82 bc 8a 4c 89 fe 4c 89 f2 49 89 d8 49 c7 c1 20 a1 fd 96 e8 12 66 ff ff <0f> 0b 66 0f 1f 00 53 48 89 fb e8 53 7a 21 f7 48 c7 c7 40 8b bc 8a
RSP: 0018:ffffc90003277300 EFLAGS: 00010246
RAX: 000000000000006e RBX: ffffffff8c7024eb RCX: 0968806d2d7b5500
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc900032773f0 R08: ffffc90003277007 R09: 1ffff9200064ee00
R10: dffffc0000000000 R11: fffff5200064ee01 R12: ffffffff8abca080
R13: ffffc90003277320 R14: ffffffff8abca060 R15: ffff88802b5be660
FS:  000055557a38e500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055564bfab8e8 CR3: 0000000077917000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 reiserfs_cut_from_item+0x1954/0x1f10 fs/reiserfs/stree.c:1727
 reiserfs_do_truncate+0xa3d/0x1340 fs/reiserfs/stree.c:1971
 reiserfs_truncate_file+0x37a/0x7c0 fs/reiserfs/inode.c:2306
 reiserfs_file_release+0x8e4/0xa50 fs/reiserfs/file.c:109
 __fput+0x234/0x970 fs/file_table.c:384
 task_work_run+0x1ce/0x250 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f810718f6c9
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:00007ffc93c54018 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 000000000001c902 RCX: 00007f810718f6c9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000593c5430f
R10: 0000001b2d020000 R11: 0000000000000246 R12: 00007f81073e5fac
R13: 00007f81073e5fa0 R14: ffffffffffffffff R15: 0000000000000002
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__reiserfs_panic+0x13e/0x140 fs/reiserfs/prints.c:390
Code: c7 c1 00 82 bc 8a 48 0f 44 c8 4c 0f 44 f0 48 c7 c7 c0 82 bc 8a 4c 89 fe 4c 89 f2 49 89 d8 49 c7 c1 20 a1 fd 96 e8 12 66 ff ff <0f> 0b 66 0f 1f 00 53 48 89 fb e8 53 7a 21 f7 48 c7 c7 40 8b bc 8a
RSP: 0018:ffffc90003277300 EFLAGS: 00010246
RAX: 000000000000006e RBX: ffffffff8c7024eb RCX: 0968806d2d7b5500
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc900032773f0 R08: ffffc90003277007 R09: 1ffff9200064ee00
R10: dffffc0000000000 R11: fffff5200064ee01 R12: ffffffff8abca080
R13: ffffc90003277320 R14: ffffffff8abca060 R15: ffff88802b5be660
FS:  000055557a38e500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c88bc3f168 CR3: 0000000077917000 CR4: 00000000003506e0

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/10 11:53 linux-6.6.y 0a805b6ea8cd 4e1406b4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan kernel BUG in reiserfs_cut_from_item
2025/11/10 10:30 linux-6.6.y 0a805b6ea8cd 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in reiserfs_cut_from_item
* Struck through repros no longer work on HEAD.