syzbot


general protection fault in dbUpdatePMap

Status: upstream: reported C repro on 2025/11/24 06:07
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+fce877b9325269d1d1af@syzkaller.appspotmail.com
First crash: 1d16h, last: 1d16h
Bug presence (1)
Date Name Commit Repro Result
2025/11/25 upstream (ToT) 30f09200cc4a C [report] stack segment fault in diUpdatePMap
Similar bugs (3)
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 8 C 4 1d07h 3d17h 0/3 upstream: reported C repro on 2025/11/22 04:56
linux-4.19 general protection fault in dbUpdatePMap 2 C error 2 1127d 1127d 0/1 upstream: reported C repro on 2022/10/25 14:29
upstream BUG: corrupted list in dbUpdatePMap jfs 8 C error 8 1h24m 19d 0/29 upstream: reported C repro on 2025/11/06 00:09

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: 1 PID: 111 Comm: jfsCommit Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__list_add_valid_or_report+0x3d/0xf0 lib/list_debug.c:29
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 d4 e3 b6 fd 49 8b 14 24 4c 39 f2
RSP: 0018:ffffc90002cf7b88 EFLAGS: 00010806
RAX: 1bd5a00000000021 RBX: dead000000000100 RCX: 0000000000000000
RDX: dead000000000100 RSI: ffffc90002639120 RDI: ffff888077eab9c0
RBP: 0000000000000a02 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200059ef54 R12: dead000000000108
R13: dffffc0000000000 R14: ffffc90002639120 R15: ffff888077eab9c0
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd8a45be000 CR3: 00000000235f5000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 __list_add_valid include/linux/list.h:88 [inline]
 __list_add include/linux/list.h:150 [inline]
 list_add include/linux/list.h:169 [inline]
 dbUpdatePMap+0x7ea/0xec0 fs/jfs/jfs_dmap.c:577
 txAllocPMap+0x57d/0x6b0 fs/jfs/jfs_txnmgr.c:2425
 txUpdateMap+0x706/0x890 fs/jfs/jfs_txnmgr.c:2363
 txLazyCommit fs/jfs/jfs_txnmgr.c:2664 [inline]
 jfs_lazycommit+0x42b/0xa60 fs/jfs/jfs_txnmgr.c:2732
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_add_valid_or_report+0x3d/0xf0 lib/list_debug.c:29
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 d4 e3 b6 fd 49 8b 14 24 4c 39 f2
RSP: 0018:ffffc90002cf7b88 EFLAGS: 00010806
RAX: 1bd5a00000000021 RBX: dead000000000100 RCX: 0000000000000000
RDX: dead000000000100 RSI: ffffc90002639120 RDI: ffff888077eab9c0
RBP: 0000000000000a02 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200059ef54 R12: dead000000000108
R13: dffffc0000000000 R14: ffffc90002639120 R15: ffff888077eab9c0
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd8a45be000 CR3: 00000000235f5000 CR4: 00000000003506e0
----------------
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 d4 e3 b6 fd       	call   0xfdb6e40d
  39:	49 8b 14 24          	mov    (%r12),%rdx
  3d:	4c 39 f2             	cmp    %r14,%rdx

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/24 06:07 linux-6.6.y 0a805b6ea8cd 4fb8ef37 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan general protection fault in dbUpdatePMap
* Struck through repros no longer work on HEAD.