syzbot


general protection fault in dbDiscardAG

Status: moderation: reported on 2025/06/20 06:22
Subsystems: jfs
[Documentation on labels]
Reported-by: syzbot+8a6ad2d2264bf9218ce2@syzkaller.appspotmail.com
First crash: 5d09h, last: 5d09h
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream UBSAN: array-index-out-of-bounds in dbDiscardAG jfs C error inconclusive 5 935d 976d 0/29 auto-obsoleted due to no activity on 2023/03/28 22:26
upstream BUG: Bad page state (8) jfs mm C 12982 243d 1601d 1/29 closed as invalid on 2024/10/28 14:11

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 1 UID: 0 PID: 6951 Comm: syz.2.144 Not tainted 6.16.0-rc1-syzkaller-00239-g08215f5486ec #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:dbDiscardAG+0x64f/0x900 fs/jfs/jfs_dmap.c:1633
Code: af c3 8b e8 33 f9 ed fd 4c 89 f7 e8 9b c4 62 fe 4c 8b 74 24 18 49 83 c6 08 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 43 ad e6 fe 49 c7 06 00 00 00 00 4c
RSP: 0018:ffffc90004cc7ca8 EFLAGS: 00010206
RAX: 0000000000000003 RBX: ffff88806a812000 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000008 RDI: 00000000ffffffff
RBP: 0000000000000001 R08: ffff888050b7dcff R09: 1ffff1100a16fb9f
R10: dffffc0000000000 R11: ffffed100a16fba0 R12: ffffffffffffffff
R13: 0000000000000001 R14: 0000000000000018 R15: ffff88806a812640
FS:  00007f6c3564b6c0(0000) GS:ffff888125d85000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555882355c8 CR3: 000000002560c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 jfs_ioc_trim+0x429/0x690 fs/jfs/jfs_discard.c:106
 jfs_ioctl+0x2b5/0x3d0 fs/jfs/ioctl.c:131
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6c3478e929
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:00007f6c3564b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f6c349b6080 RCX: 00007f6c3478e929
RDX: 0000200000000080 RSI: 00000000c0185879 RDI: 0000000000000007
RBP: 00007f6c34810b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6c349b6080 R15: 00007ffea3f0bef8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dbDiscardAG+0x64f/0x900 fs/jfs/jfs_dmap.c:1633
Code: af c3 8b e8 33 f9 ed fd 4c 89 f7 e8 9b c4 62 fe 4c 8b 74 24 18 49 83 c6 08 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 43 ad e6 fe 49 c7 06 00 00 00 00 4c
RSP: 0018:ffffc90004cc7ca8 EFLAGS: 00010206
RAX: 0000000000000003 RBX: ffff88806a812000 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000008 RDI: 00000000ffffffff
RBP: 0000000000000001 R08: ffff888050b7dcff R09: 1ffff1100a16fb9f
R10: dffffc0000000000 R11: ffffed100a16fba0 R12: ffffffffffffffff
R13: 0000000000000001 R14: 0000000000000018 R15: ffff88806a812640
FS:  00007f6c3564b6c0(0000) GS:ffff888125d85000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb7d97182f0 CR3: 000000002560c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	af                   	scas   %es:(%rdi),%eax
   1:	c3                   	ret
   2:	8b e8                	mov    %eax,%ebp
   4:	33 f9                	xor    %ecx,%edi
   6:	ed                   	in     (%dx),%eax
   7:	fd                   	std
   8:	4c 89 f7             	mov    %r14,%rdi
   b:	e8 9b c4 62 fe       	call   0xfe62c4ab
  10:	4c 8b 74 24 18       	mov    0x18(%rsp),%r14
  15:	49 83 c6 08          	add    $0x8,%r14
  19:	4c 89 f0             	mov    %r14,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	4c 89 f7             	mov    %r14,%rdi
  33:	e8 43 ad e6 fe       	call   0xfee6ad7b
  38:	49 c7 06 00 00 00 00 	movq   $0x0,(%r14)
  3f:	4c                   	rex.WR

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/16 06:13 upstream 08215f5486ec 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs general protection fault in dbDiscardAG
* Struck through repros no longer work on HEAD.