syzbot


KASAN: vmalloc-out-of-bounds Read in gfs2_dump_glock

Status: upstream: reported C repro on 2025/07/23 07:10
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+e64ba62ab1a818bac144@syzkaller.appspotmail.com
First crash: 29d, last: 15d
Bug presence (1)
Date Name Commit Repro Result
2025/07/30 upstream (ToT) e8d780dcd957 C [report] general protection fault in gfs2_dump_glock
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: stack-out-of-bounds Read in gfs2_dump_glock origin:upstream 17 C error 45 120d 842d 0/3 upstream: reported C repro on 2023/05/02 11:39
upstream KASAN: stack-out-of-bounds Read in gfs2_dump_glock gfs2 19 C error 371 21h50m 473d 0/29 upstream: reported C repro on 2024/05/04 22:05
upstream general protection fault in gfs2_dump_glock gfs2 17 C 25 911d 1312d 22/29 fixed on 2023/02/24 13:50
upstream general protection fault in gfs2_dump_glock (2) gfs2 17 C done done 48 591d 899d 0/29 auto-obsoleted due to no activity on 2024/04/08 04:28

Sample crash report:
gfs2: fsid=syz:syz.0:  H: s:SH f:H e:0 p:6091 [syz.0.50] __gfs2_lookup+0x90/0x270 fs/gfs2/inode.c:896
general protection fault, probably for non-canonical address 0xdffffc0008bc06c5: 0000 [#1] PREEMPT SMP KASAN
KASAN: probably user-memory-access in range [0x0000000045e03628-0x0000000045e0362f]
CPU: 1 PID: 6093 Comm: syz.0.50 Not tainted 6.6.100-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pid_is_meaningful fs/gfs2/glock.c:1502 [inline]
RIP: 0010:dump_holder fs/gfs2/glock.c:2308 [inline]
RIP: 0010:gfs2_dump_glock+0xd5f/0x1920 fs/gfs2/glock.c:2424
Code: e0 8d ef 8a be 14 03 00 00 48 c7 c2 20 8e ef 8a e8 f6 ae c8 fd 49 8d 5d 20 49 89 de 49 c1 ee 03 48 b8 00 00 00 00 00 fc ff df <41> 0f b6 04 06 84 c0 0f 85 10 06 00 00 48 89 5c 24 38 0f b7 1b 89
RSP: 0018:ffffc90003696ee0 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: 0000000045e0362e RCX: ffff88807ce7da00
RDX: 0000000000000000 RSI: ffffffff8afc66e0 RDI: ffffffff8afc66a0
RBP: ffffc900036971d0 R08: dffffc0000000000 R09: 1ffffffff21b46a4
R10: dffffc0000000000 R11: fffffbfff21b46a5 R12: ffffffff839f0b9f
R13: 0000000045e0360e R14: 0000000008bc06c5 R15: 0000000000000000
FS:  00007fa8413de6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5586b91000 CR3: 0000000060c10000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 gfs2_consist_inode_i+0xf5/0x110 fs/gfs2/util.c:455
 gfs2_dirent_scan+0x525/0x650 fs/gfs2/dir.c:602
 gfs2_dirent_search+0x2e1/0x7e0 fs/gfs2/dir.c:850
 gfs2_dir_search+0x4d/0x220 fs/gfs2/dir.c:1650
 gfs2_lookupi+0x3d9/0x5a0 fs/gfs2/inode.c:339
 __gfs2_lookup+0x90/0x270 fs/gfs2/inode.c:896
 __lookup_slow+0x281/0x3b0 fs/namei.c:1694
 lookup_slow+0x53/0x70 fs/namei.c:1711
 walk_component fs/namei.c:2002 [inline]
 link_path_walk+0x970/0xe00 fs/namei.c:2329
 path_lookupat+0x9d/0x440 fs/namei.c:2482
 do_o_path+0x98/0x1f0 fs/namei.c:3760
 path_openat+0x2a31/0x3190 fs/namei.c:3782
 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
 do_sys_open fs/open.c:1434 [inline]
 __do_sys_openat fs/open.c:1450 [inline]
 __se_sys_openat fs/open.c:1445 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1445
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa84158e9a9
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:00007fa8413de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fa8417b6080 RCX: 00007fa84158e9a9
RDX: 0000000000200002 RSI: 00002000000000c0 RDI: ffffffffffffff9c
RBP: 00007fa841610d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fa8417b6080 R15: 00007ffeda133c88
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:pid_is_meaningful fs/gfs2/glock.c:1502 [inline]
RIP: 0010:dump_holder fs/gfs2/glock.c:2308 [inline]
RIP: 0010:gfs2_dump_glock+0xd5f/0x1920 fs/gfs2/glock.c:2424
Code: e0 8d ef 8a be 14 03 00 00 48 c7 c2 20 8e ef 8a e8 f6 ae c8 fd 49 8d 5d 20 49 89 de 49 c1 ee 03 48 b8 00 00 00 00 00 fc ff df <41> 0f b6 04 06 84 c0 0f 85 10 06 00 00 48 89 5c 24 38 0f b7 1b 89
RSP: 0018:ffffc90003696ee0 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: 0000000045e0362e RCX: ffff88807ce7da00
RDX: 0000000000000000 RSI: ffffffff8afc66e0 RDI: ffffffff8afc66a0
RBP: ffffc900036971d0 R08: dffffc0000000000 R09: 1ffffffff21b46a4
R10: dffffc0000000000 R11: fffffbfff21b46a5 R12: ffffffff839f0b9f
R13: 0000000045e0360e R14: 0000000008bc06c5 R15: 0000000000000000
FS:  00007fa8413de6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa8413ddf98 CR3: 0000000060c10000 CR4: 00000000003506f0
----------------
Code disassembly (best guess):
   0:	e0 8d                	loopne 0xffffff8f
   2:	ef                   	out    %eax,(%dx)
   3:	8a be 14 03 00 00    	mov    0x314(%rsi),%bh
   9:	48 c7 c2 20 8e ef 8a 	mov    $0xffffffff8aef8e20,%rdx
  10:	e8 f6 ae c8 fd       	call   0xfdc8af0b
  15:	49 8d 5d 20          	lea    0x20(%r13),%rbx
  19:	49 89 de             	mov    %rbx,%r14
  1c:	49 c1 ee 03          	shr    $0x3,%r14
  20:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  27:	fc ff df
* 2a:	41 0f b6 04 06       	movzbl (%r14,%rax,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 10 06 00 00    	jne    0x647
  37:	48 89 5c 24 38       	mov    %rbx,0x38(%rsp)
  3c:	0f b7 1b             	movzwl (%rbx),%ebx
  3f:	89                   	.byte 0x89

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/26 04:30 linux-6.6.y dbcb8d8e4163 fb8f743d .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 gfs2_dump_glock
2025/07/25 14:36 linux-6.6.y dbcb8d8e4163 fb8f743d .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 gfs2_dump_glock
2025/07/23 07:10 linux-6.6.y d96eb99e2f0e e1dd4f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: vmalloc-out-of-bounds Read in gfs2_dump_glock
2025/08/06 02:35 linux-6.6.y 3a8ababb8b6a ffe1dd46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in gfs2_dump_glock
2025/07/25 05:11 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in gfs2_dump_glock
* Struck through repros no longer work on HEAD.