syzbot


general protection fault in gfs2_print_dbg (3)

Status: upstream: reported C repro on 2025/09/15 18:18
Subsystems: gfs2
[Documentation on labels]
Reported-by: syzbot+fa7122891ab9e0bbc6a7@syzkaller.appspotmail.com
First crash: 2d00h, last: 1d23h
Cause bisection: failed (error log, bisect log)
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [gfs2?] general protection fault in gfs2_print_dbg (3) 0 (1) 2025/09/15 18:18
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in gfs2_print_dbg (2) gfs2 2 1 869d 868d 0/29 auto-obsoleted due to no activity on 2023/07/29 23:54
upstream general protection fault in gfs2_print_dbg gfs2 2 1 1023d 1022d 0/29 auto-obsoleted due to no activity on 2023/03/27 21:40
linux-6.1 BUG: unable to handle kernel paging request in gfs2_print_dbg origin:upstream missing-backport 8 syz error 2 190d 190d 0/3 upstream: reported syz repro on 2025/03/09 04:33

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xe7697c1115925d6c: 0000 [#1] SMP KASAN PTI
KASAN: maybe wild-memory-access in range [0x3b4c0088ac92eb60-0x3b4c0088ac92eb67]
CPU: 1 UID: 0 PID: 6163 Comm: syz.0.38 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:string_nocheck lib/vsprintf.c:653 [inline]
RIP: 0010:string+0x1bb/0x2b0 lib/vsprintf.c:735
Code: 15 a5 f6 eb b3 41 c1 fd 10 4c 89 6c 24 10 49 8d 5d ff 45 31 ed 4b 8d 3c 2c 48 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 75 60 4b 8d 2c 2e 47 0f b6 3c 2c 31 ff 44 89 fe
RSP: 0018:ffffc9000383ef00 EFLAGS: 00010007
RAX: 0769801115925d6c RBX: 00000000fffffffe RCX: dffffc0000000000
RDX: ffff88802a435ac0 RSI: 00000000ffff0a00 RDI: 3b4c0088ac92eb67
RBP: ffffffff8bf0acfe R08: ffff88802a435ac0 R09: 0000000000000008
R10: 0000000000000007 R11: 0000000000000000 R12: 3b4c0088ac92eb67
R13: 0000000000000000 R14: ffffc9000383f319 R15: 0000000000000030
FS:  00007fde6f5cd6c0(0000) GS:ffff888125ae8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f425685d000 CR3: 000000007d39e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 vsnprintf+0x739/0xf00 lib/vsprintf.c:2926
 va_format lib/vsprintf.c:1728 [inline]
 pointer+0x940/0x1190 lib/vsprintf.c:2548
 vsnprintf+0x60f/0xf00 lib/vsprintf.c:2930
 vprintk_store+0x3c7/0xd00 kernel/printk/printk.c:2252
 vprintk_emit+0x15f/0x590 kernel/printk/printk.c:2399
 _printk+0xcf/0x120 kernel/printk/printk.c:2448
 gfs2_print_dbg+0x19a/0x1b0 fs/gfs2/glock.c:1444
 dump_holder fs/gfs2/glock.c:2287 [inline]
 gfs2_dump_glock+0x152d/0x1bc0 fs/gfs2/glock.c:2398
 gfs2_consist_inode_i+0xf5/0x110 fs/gfs2/util.c:446
 gfs2_dirent_scan+0x545/0x690 fs/gfs2/dir.c:-1
 gfs2_dir_read+0x804/0x16f0 fs/gfs2/dir.c:1600
 gfs2_readdir+0x14c/0x1b0 fs/gfs2/file.c:116
 iterate_dir+0x399/0x570 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:410 [inline]
 __se_sys_getdents64+0xe4/0x260 fs/readdir.c:396
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fde6e78eba9
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:00007fde6f5cd038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007fde6e9d6090 RCX: 00007fde6e78eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007fde6e811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fde6e9d6128 R14: 00007fde6e9d6090 R15: 00007ffeeef80a98
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:string_nocheck lib/vsprintf.c:653 [inline]
RIP: 0010:string+0x1bb/0x2b0 lib/vsprintf.c:735
Code: 15 a5 f6 eb b3 41 c1 fd 10 4c 89 6c 24 10 49 8d 5d ff 45 31 ed 4b 8d 3c 2c 48 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 75 60 4b 8d 2c 2e 47 0f b6 3c 2c 31 ff 44 89 fe
RSP: 0018:ffffc9000383ef00 EFLAGS: 00010007
RAX: 0769801115925d6c RBX: 00000000fffffffe RCX: dffffc0000000000
RDX: ffff88802a435ac0 RSI: 00000000ffff0a00 RDI: 3b4c0088ac92eb67
RBP: ffffffff8bf0acfe R08: ffff88802a435ac0 R09: 0000000000000008
R10: 0000000000000007 R11: 0000000000000000 R12: 3b4c0088ac92eb67
R13: 0000000000000000 R14: ffffc9000383f319 R15: 0000000000000030
FS:  00007fde6f5cd6c0(0000) GS:ffff888125ae8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f425685d000 CR3: 000000007d39e000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	15 a5 f6 eb b3       	adc    $0xb3ebf6a5,%eax
   5:	41 c1 fd 10          	sar    $0x10,%r13d
   9:	4c 89 6c 24 10       	mov    %r13,0x10(%rsp)
   e:	49 8d 5d ff          	lea    -0x1(%r13),%rbx
  12:	45 31 ed             	xor    %r13d,%r13d
  15:	4b 8d 3c 2c          	lea    (%r12,%r13,1),%rdi
  19:	48 89 f8             	mov    %rdi,%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:	0f b6 04 08          	movzbl (%rax,%rcx,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	75 60                	jne    0x92
  32:	4b 8d 2c 2e          	lea    (%r14,%r13,1),%rbp
  36:	47 0f b6 3c 2c       	movzbl (%r12,%r13,1),%r15d
  3b:	31 ff                	xor    %edi,%edi
  3d:	44 89 fe             	mov    %r15d,%esi

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/14 03:46 linux-next 590b221ed425 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root general protection fault in gfs2_print_dbg
2025/09/14 02:41 linux-next 590b221ed425 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root general protection fault in gfs2_print_dbg
* Struck through repros no longer work on HEAD.