syzbot


kernel BUG in reiserfs_rename

Status: upstream: reported C repro on 2023/09/29 12:23
Bug presence: origin:lts-only
Labels: missing-backport
[Documentation on labels]
Reported-by: syzbot+a89eaa265d749c0ffb2e@syzkaller.appspotmail.com
First crash: 814d, last: 20d
Fix commit to backport (bisect log) :
tree: upstream
commit 18048c1af7836b8e31739d9eaefebc2bf76261f7
Author: Gulam Mohamed <gulam.mohamed@oracle.com>
Date: Tue Jun 18 16:40:42 2024 +0000

  loop: Fix a race between loop detach and loop open

  
Fix bisection: the issue occurs on the latest tested release (bisect log)
Crash: kernel BUG in drop_new_inode (log)
Repro: C syz .config
  
Bug presence (2)
Date Name Commit Repro Result
2025/12/01 linux-6.1.y (ToT) f6e38ae624cf C [report] kernel BUG in reiserfs_rename
2025/12/01 upstream (ToT) 7d0a66e4bb90 C Didn't crash
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 kernel BUG in reiserfs_rename missing-backport -1 C error 2 7d09h 699d 0/3 upstream: reported C repro on 2024/01/22 10:19
upstream kernel BUG in reiserfs_rename fs -1 C unreliable done 6 702d 877d 0/29 auto-obsoleted due to no activity on 2024/04/28 17:48
Fix bisection attempts (11)
Created Duration User Patch Repo Result
2024/09/13 14:26 8h39m fix candidate upstream OK (1) job log
2024/09/10 19:51 3h33m bisect fix linux-6.1.y OK (0) job log log
2024/08/07 09:02 3h25m bisect fix linux-6.1.y OK (0) job log log
2024/06/28 00:55 2h16m bisect fix linux-6.1.y OK (0) job log log
2024/05/19 20:23 2h22m bisect fix linux-6.1.y OK (0) job log log
2024/04/14 15:07 3h36m bisect fix linux-6.1.y OK (0) job log log
2024/03/12 14:48 2h27m bisect fix linux-6.1.y OK (0) job log log
2024/02/03 14:01 2h26m (2) bisect fix linux-6.1.y OK (0) job log log
2023/12/31 01:10 2h17m bisect fix linux-6.1.y OK (0) job log log
2023/11/30 20:50 2h20m bisect fix linux-6.1.y OK (0) job log log
2023/10/30 19:17 2h28m bisect fix linux-6.1.y OK (0) job log log

Sample crash report:
REISERFS (device loop0): checking transaction log (loop0)
REISERFS (device loop0): Using r5 hash to sort names
REISERFS error (device loop0): zam-7002 reiserfs_add_entry: reiserfs_find_entry() returned unexpected value (3)
REISERFS (device loop0): Remounting filesystem read-only
REISERFS panic (device loop0): vs-7050 reiserfs_rename: new entry is found, new inode == 0
------------[ cut here ]------------
kernel BUG at fs/reiserfs/prints.c:390!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 4754 Comm: syz.0.174 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__reiserfs_panic+0x13a/0x140 fs/reiserfs/prints.c:390
Code: c7 c1 80 46 9e 8a 48 0f 44 c8 4c 0f 44 f0 48 c7 c7 40 47 9e 8a 4c 89 fe 4c 89 f2 49 89 d8 49 c7 c1 00 30 d7 96 e8 76 83 ff ff <0f> 0b 0f 1f 40 00 53 48 89 fb e8 17 94 73 f7 48 c7 c7 c0 4f 9e 8a
RSP: 0018:ffffc9000d3074e0 EFLAGS: 00010246
RAX: 000000000000005a RBX: ffffffff8c41b7d3 RCX: 5717965ad6655000
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc9000d3075d0 R08: dffffc0000000000 R09: fffff52001a60e3d
R10: fffff52001a60e3d R11: 1ffff92001a60e3c R12: ffffffff8a9df240
R13: ffffc9000d307500 R14: ffffffff8a9df220 R15: ffff88807a9366a8
FS:  000055555fcd7500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000074b73000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 reiserfs_rename+0x1c10/0x1eb0 fs/reiserfs/namei.c:1427
 vfs_rename+0xbbf/0x10d0 fs/namei.c:4882
 do_renameat2+0x89d/0xc70 fs/namei.c:5035
 __do_sys_rename fs/namei.c:5081 [inline]
 __se_sys_rename fs/namei.c:5079 [inline]
 __x64_sys_rename+0x82/0x90 fs/namei.c:5079
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5c7178f749
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:00007ffca018cdb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007f5c719e5fa0 RCX: 00007f5c7178f749
RDX: 0000000000000000 RSI: 0000200000000080 RDI: 0000200000000000
RBP: 00007f5c71813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5c719e5fa0 R14: 00007f5c719e5fa0 R15: 0000000000000002
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__reiserfs_panic+0x13a/0x140 fs/reiserfs/prints.c:390
Code: c7 c1 80 46 9e 8a 48 0f 44 c8 4c 0f 44 f0 48 c7 c7 40 47 9e 8a 4c 89 fe 4c 89 f2 49 89 d8 49 c7 c1 00 30 d7 96 e8 76 83 ff ff <0f> 0b 0f 1f 40 00 53 48 89 fb e8 17 94 73 f7 48 c7 c7 c0 4f 9e 8a
RSP: 0018:ffffc9000d3074e0 EFLAGS: 00010246
RAX: 000000000000005a RBX: ffffffff8c41b7d3 RCX: 5717965ad6655000
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc9000d3075d0 R08: dffffc0000000000 R09: fffff52001a60e3d
R10: fffff52001a60e3d R11: 1ffff92001a60e3c R12: ffffffff8a9df240
R13: ffffc9000d307500 R14: ffffffff8a9df220 R15: ffff88807a9366a8
FS:  000055555fcd7500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9654680000 CR3: 0000000074b73000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/30 16:19 linux-6.1.y f6e38ae624cf d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (corrupt fs)] ci2-linux-6-1-kasan kernel BUG in reiserfs_rename
2023/09/29 12:22 linux-6.1.y d23900f974e0 d265efd8 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 kernel BUG in reiserfs_rename
* Struck through repros no longer work on HEAD.