syzbot


BUG: corrupted list in dbUpdatePMap

Status: upstream: reported C repro on 2026/01/02 10:13
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+c0c71dfd0972587b1966@syzkaller.appspotmail.com
First crash: 17d, last: 13d
Bug presence (1)
Date Name Commit Repro Result
2026/01/05 upstream (ToT) 3609fa95fb0f C [report] stack segment fault in diUpdatePMap
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 BUG: unable to handle kernel paging request in dbUpdatePMap origin:upstream 8 C 16 5h50m 58d 0/3 upstream: reported C repro on 2025/11/22 04:56
upstream BUG: corrupted list in dbUpdatePMap jfs 8 C error 71 1d08h 74d 0/29 upstream: reported C repro on 2025/11/06 00:09
linux-6.6 general protection fault in dbUpdatePMap origin:upstream 8 C 3 26d 56d 0/2 upstream: reported C repro on 2025/11/24 06:07
linux-4.19 general protection fault in dbUpdatePMap 2 C error 2 1182d 1182d 0/1 upstream: reported C repro on 2022/10/25 14:29

Sample crash report:
general protection fault, probably for non-canonical address 0xfbd59c0000000021: 0000 [#1] PREEMPT SMP KASAN
KASAN: maybe wild-memory-access in range [0xdead000000000108-0xdead00000000010f]
CPU: 0 PID: 277 Comm: jfsCommit Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__list_add_valid+0x39/0xe0 lib/list_debug.c:27
Code: 00 00 00 48 89 d3 48 85 d2 0f 84 8c 00 00 00 49 89 f6 49 89 ff 49 bd 00 00 00 00 00 fc ff df 4c 8d 63 08 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 a8 24 dd fd 49 8b 14 24 4c 39 f2
RSP: 0018:ffffc90002bdfbd0 EFLAGS: 00010806
RAX: 1bd5a00000000021 RBX: dead000000000100 RCX: ffff88801d9fd940
RDX: dead000000000100 RSI: ffffc90002531230 RDI: ffff888079dc24e8
RBP: ffff888078b5d21c R08: 0000000000000004 R09: 0000000000000003
R10: fffff5200057bf5c R11: 1ffff9200057bf5c R12: dead000000000108
R13: dffffc0000000000 R14: ffffc90002531230 R15: ffff888079dc24e8
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f478fdf6000 CR3: 0000000075373000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __list_add include/linux/list.h:67 [inline]
 list_add include/linux/list.h:86 [inline]
 dbUpdatePMap+0x6da/0xdb0 fs/jfs/jfs_dmap.c:577
 txAllocPMap+0x57d/0x6b0 fs/jfs/jfs_txnmgr.c:2460
 txUpdateMap+0x706/0x890 fs/jfs/jfs_txnmgr.c:2398
 txLazyCommit fs/jfs/jfs_txnmgr.c:2699 [inline]
 jfs_lazycommit+0x437/0xb20 fs/jfs/jfs_txnmgr.c:2767
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Modules linked in:
---[ end trace 3237712255a8b4ae ]---
RIP: 0010:__list_add_valid+0x39/0xe0 lib/list_debug.c:27
Code: 00 00 00 48 89 d3 48 85 d2 0f 84 8c 00 00 00 49 89 f6 49 89 ff 49 bd 00 00 00 00 00 fc ff df 4c 8d 63 08 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 a8 24 dd fd 49 8b 14 24 4c 39 f2
RSP: 0018:ffffc90002bdfbd0 EFLAGS: 00010806
RAX: 1bd5a00000000021 RBX: dead000000000100 RCX: ffff88801d9fd940
RDX: dead000000000100 RSI: ffffc90002531230 RDI: ffff888079dc24e8
RBP: ffff888078b5d21c R08: 0000000000000004 R09: 0000000000000003
R10: fffff5200057bf5c R11: 1ffff9200057bf5c R12: dead000000000108
R13: dffffc0000000000 R14: ffffc90002531230 R15: ffff888079dc24e8
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f478fdf6000 CR3: 0000000075373000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	00 48 89             	add    %cl,-0x77(%rax)
   5:	d3 48 85             	rorl   %cl,-0x7b(%rax)
   8:	d2 0f                	rorb   %cl,(%rdi)
   a:	84 8c 00 00 00 49 89 	test   %cl,-0x76b70000(%rax,%rax,1)
  11:	f6 49 89 ff          	testb  $0xff,-0x77(%rcx)
  15:	49 bd 00 00 00 00 00 	movabs $0xdffffc0000000000,%r13
  1c:	fc ff df
  1f:	4c 8d 63 08          	lea    0x8(%rbx),%r12
  23:	4c 89 e0             	mov    %r12,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 e7             	mov    %r12,%rdi
  34:	e8 a8 24 dd fd       	call   0xfddd24e1
  39:	49 8b 14 24          	mov    (%r12),%rdx
  3d:	4c 39 f2             	cmp    %r14,%rdx

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/05 20:10 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan general protection fault in dbUpdatePMap
2026/01/05 11:22 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan general protection fault in dbUpdatePMap
2026/01/06 01:18 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan general protection fault in dbUpdatePMap
2026/01/02 10:12 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan BUG: corrupted list in dbUpdatePMap
* Struck through repros no longer work on HEAD.