syzbot


kernel BUG in txLock

Status: upstream: reported C repro on 2025/12/24 20:44
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+be3c412c65c3d627c752@syzkaller.appspotmail.com
First crash: 21d, last: 3d16h
Bug presence (1)
Date Name Commit Repro Result
2025/12/31 upstream (ToT) dbf8fe85a16a C [report] kernel BUG in txLock
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 kernel BUG in txLock (2) origin:upstream -1 C 9 5d22h 415d 0/3 upstream: reported C repro on 2024/11/25 09:43
linux-5.15 kernel BUG in txLock -1 1 860d 860d 0/3 auto-obsoleted due to no activity on 2023/12/16 09:17
upstream kernel BUG in txLock (2) jfs -1 C error error 285 7h56m 657d 0/29 upstream: reported C repro on 2024/03/28 08:26
upstream kernel BUG in txLock jfs -1 C inconclusive done 10 740d 858d 25/29 fixed on 2024/02/16 19:40
linux-6.1 kernel BUG in txLock origin:upstream -1 C 12 2d08h 304d 0/3 upstream: reported C repro on 2025/03/16 14:14

Sample crash report:
BUG at fs/jfs/jfs_txnmgr.c:662 assert(last)
------------[ cut here ]------------
kernel BUG at fs/jfs/jfs_txnmgr.c:662!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 6052 Comm: syz.1.18 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:txLock+0x1cc1/0x2090 fs/jfs/jfs_txnmgr.c:662
Code: fe e9 29 f8 ff ff e8 ae 78 84 fe 48 c7 c7 00 10 e4 8a 48 c7 c6 f9 0b e4 8a ba 96 02 00 00 48 c7 c1 00 11 e4 8a e8 2f 13 5b 07 <0f> 0b e8 88 78 84 fe 48 c7 c7 c0 11 e4 8a e8 1c 13 5b 07 48 c7 c7
RSP: 0018:ffffc90003836880 EFLAGS: 00010246
RAX: 000000000000002b RBX: ffffc9000282a000 RCX: 08cd9b7b3ed83d00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc900038369c8 R08: ffffc90003836587 R09: 1ffff92000706cb0
R10: dffffc0000000000 R11: fffff52000706cb1 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff92000505400
FS:  000055557ba77500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007effac3d0000 CR3: 000000002e1e5000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 diWrite+0x43f/0x1f20 fs/jfs/jfs_imap.c:654
 txCommit+0x84c/0x5250 fs/jfs/jfs_txnmgr.c:1256
 jfs_commit_inode+0x2f0/0x520 fs/jfs/inode.c:114
 extAlloc+0xb9b/0xf30 fs/jfs/jfs_extent.c:172
 jfs_get_block+0x347/0xab0 fs/jfs/inode.c:254
 __block_write_begin_int+0x566/0x1ad0 fs/buffer.c:2124
 __block_write_begin fs/buffer.c:2173 [inline]
 block_write_begin+0x9a/0x1e0 fs/buffer.c:2234
 jfs_write_begin+0x35/0x70 fs/jfs/inode.c:305
 generic_perform_write+0x2fb/0x5b0 mm/filemap.c:4031
 generic_file_write_iter+0xaf/0x2e0 mm/filemap.c:4152
 __kernel_write_iter+0x274/0x670 fs/read_write.c:517
 dump_emit_page fs/coredump.c:957 [inline]
 dump_user_range+0x3f6/0x800 fs/coredump.c:984
 elf_core_dump+0x3114/0x36e0 fs/binfmt_elf.c:2184
 do_coredump+0x1755/0x2480 fs/coredump.c:833
 get_signal+0x1133/0x1400 kernel/signal.c:2888
 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315
 exc_page_fault+0x8f/0x110 arch/x86/mm/fault.c:1524
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f2a4238f751
Code: 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 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f2a425e5fa0 RCX: 00007f2a4238f749
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f2a42413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f2a425e5fa0 R14: 00007f2a425e5fa0 R15: 0000000000000006
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:txLock+0x1cc1/0x2090 fs/jfs/jfs_txnmgr.c:662
Code: fe e9 29 f8 ff ff e8 ae 78 84 fe 48 c7 c7 00 10 e4 8a 48 c7 c6 f9 0b e4 8a ba 96 02 00 00 48 c7 c1 00 11 e4 8a e8 2f 13 5b 07 <0f> 0b e8 88 78 84 fe 48 c7 c7 c0 11 e4 8a e8 1c 13 5b 07 48 c7 c7
RSP: 0018:ffffc90003836880 EFLAGS: 00010246
RAX: 000000000000002b RBX: ffffc9000282a000 RCX: 08cd9b7b3ed83d00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc900038369c8 R08: ffffc90003836587 R09: 1ffff92000706cb0
R10: dffffc0000000000 R11: fffff52000706cb1 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff92000505400
FS:  000055557ba77500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007effac3e7000 CR3: 000000002e1e5000 CR4: 00000000003506e0

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/24 22:22 linux-6.6.y 5fa4793a2d2d d6526ea3 .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 txLock
2025/12/25 00:50 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan kernel BUG in txLock
2025/12/24 23:36 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan kernel BUG in txLock
2026/01/11 08:03 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in txLock
2025/12/25 04:22 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in txLock
2025/12/24 20:43 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in txLock
* Struck through repros no longer work on HEAD.