* [syzbot] [gfs2?] general protection fault in gfs2_glock_dq (2)
@ 2025-12-26 11:22 syzbot
2026-06-20 5:44 ` syzbot
0 siblings, 1 reply; 2+ messages in thread
From: syzbot @ 2025-12-26 11:22 UTC (permalink / raw)
To: agruenba, gfs2, linux-kernel, syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: ccd1cdca5cd4 Merge tag 'nfsd-6.19-1' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1244ebb4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=513255d80ab78f2b
dashboard link: https://syzkaller.appspot.com/bug?extid=5a5f492ccae698fd7434
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-ccd1cdca.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6a642b40c399/vmlinux-ccd1cdca.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bbe8deda746e/bzImage-ccd1cdca.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5a5f492ccae698fd7434@syzkaller.appspotmail.com
loop0: detected capacity change from 0 to 32768
gfs2: fsid=syz:syz: Trying to join cluster "lock_nolock", "syz:syz"
gfs2: fsid=syz:syz: Now mounting FS (format 1801)...
gfs2: fsid=syz:syz.0: journal 0 mapped with 1 extents in 0ms
gfs2: fsid=syz:syz.0: first mount done, others may mount
loop0: detected capacity change from 32768 to 0
gfs2: fsid=syz:syz.0: Error -5 writing to journal, jid=0
CPU: 0 UID: 0 PID: 5347 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
gfs2_withdraw+0xc3/0x1b0 fs/gfs2/util.c:250
gfs2_end_log_write+0xcd/0x7c0 fs/gfs2/lops.c:212
gfs2_log_submit_bio+0x99/0xe0 fs/gfs2/lops.c:247
gfs2_log_flush+0xb0f/0x24c0 fs/gfs2/log.c:1099
gfs2_write_inode+0x23f/0x3e0 fs/gfs2/super.c:447
write_inode fs/fs-writeback.c:1582 [inline]
__writeback_single_inode+0x7e1/0x1240 fs/fs-writeback.c:1802
writeback_single_inode+0x493/0xc70 fs/fs-writeback.c:1858
sync_inode_metadata+0xb9/0x110 fs/fs-writeback.c:2944
gfs2_fsync+0x1a6/0x370 fs/gfs2/file.c:763
vfs_fsync_range fs/sync.c:188 [inline]
vfs_fsync fs/sync.c:202 [inline]
do_fsync fs/sync.c:213 [inline]
__do_sys_fdatasync fs/sync.c:223 [inline]
__se_sys_fdatasync fs/sync.c:221 [inline]
__x64_sys_fdatasync+0xb9/0x110 fs/sync.c:221
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f871158f7c9
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:00007f870d9f5038 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
RAX: ffffffffffffffda RBX: 00007f87117e5fa0 RCX: 00007f871158f7c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007f8711613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f87117e6038 R14: 00007f87117e5fa0 R15: 00007ffde92d9398
</TASK>
gfs2: fsid=syz:syz.0: about to withdraw this file system
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]
CPU: 0 UID: 0 PID: 5347 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:210
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 e9 80 d5 35 09 cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc9000e2f7b68 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffffffff8b5e25de RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8b5e25de RDI: 0000000000000007
RBP: ffffffff8400f3f0 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1008cd3957 R12: 0000000000000000
R13: 0000000000000038 R14: 0000000000000038 R15: 0000000000000001
FS: 00007f870d9f56c0(0000) GS:ffff88808d416000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000565502ea78c0 CR3: 0000000011bc9000 CR4: 0000000000352ef0
Call Trace:
<TASK>
__kasan_check_byte+0x12/0x40 mm/kasan/common.c:572
kasan_check_byte include/linux/kasan.h:401 [inline]
lock_acquire+0x84/0x340 kernel/locking/lockdep.c:5842
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
gfs2_glock_dq+0x50/0x7c0 fs/gfs2/glock.c:1577
gfs2_glock_dq_uninit+0x25/0xb0 fs/gfs2/glock.c:1623
gfs2_seek_data+0x16c/0x240 fs/gfs2/inode.c:2218
gfs2_llseek+0x1a4/0x240 fs/gfs2/file.c:75
vfs_llseek fs/read_write.c:389 [inline]
ksys_lseek fs/read_write.c:402 [inline]
__do_sys_lseek fs/read_write.c:412 [inline]
__se_sys_lseek fs/read_write.c:410 [inline]
__x64_sys_lseek+0x14f/0x1e0 fs/read_write.c:410
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f871158f7c9
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:00007f870d9f5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000008
RAX: ffffffffffffffda RBX: 00007f87117e5fa0 RCX: 00007f871158f7c9
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007f8711613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f87117e6038 R14: 00007f87117e5fa0 R15: 00007ffde92d9398
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:210
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 e9 80 d5 35 09 cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc9000e2f7b68 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffffffff8b5e25de RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8b5e25de RDI: 0000000000000007
RBP: ffffffff8400f3f0 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1008cd3957 R12: 0000000000000000
R13: 0000000000000038 R14: 0000000000000038 R15: 0000000000000001
FS: 00007f870d9f56c0(0000) GS:ffff88808d416000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000565502ea78c0 CR3: 0000000011bc9000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1)
7: 00
8: 90 nop
9: 90 nop
a: 90 nop
b: 90 nop
c: 90 nop
d: 90 nop
e: 90 nop
f: 90 nop
10: 90 nop
11: 90 nop
12: 90 nop
13: 90 nop
14: 90 nop
15: 90 nop
16: 90 nop
17: 90 nop
18: 0f 1f 40 d6 nopl -0x2a(%rax)
1c: 48 c1 ef 03 shr $0x3,%rdi
20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
27: fc ff df
* 2a: 0f b6 04 07 movzbl (%rdi,%rax,1),%eax <-- trapping instruction
2e: 3c 08 cmp $0x8,%al
30: 0f 92 c0 setb %al
33: e9 80 d5 35 09 jmp 0x935d5b8
38: cc int3
39: 66 data16
3a: 66 data16
3b: 66 data16
3c: 66 data16
3d: 66 data16
3e: 66 data16
3f: 2e cs
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [syzbot] [gfs2?] general protection fault in gfs2_glock_dq (2)
2025-12-26 11:22 [syzbot] [gfs2?] general protection fault in gfs2_glock_dq (2) syzbot
@ 2026-06-20 5:44 ` syzbot
0 siblings, 0 replies; 2+ messages in thread
From: syzbot @ 2026-06-20 5:44 UTC (permalink / raw)
To: agruenba, gfs2, linux-kernel, syzkaller-bugs
syzbot has found a reproducer for the following issue on:
HEAD commit: a975094bf98c Merge tag 'exfat-for-7.2-rc1' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=157bc2ae580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f5fece1a9477c321
dashboard link: https://syzkaller.appspot.com/bug?extid=5a5f492ccae698fd7434
compiler: Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1391e566580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10e34d56580000
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-a975094b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3c6e219ebae0/vmlinux-a975094b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8ee0600dd547/bzImage-a975094b.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/b036c6932e75/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=12d95b7a580000)
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5a5f492ccae698fd7434@syzkaller.appspotmail.com
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4deac15fac R14: 00007f4deac15fa0 R15: 00007f4deac15fa0
</TASK>
gfs2: fsid=syz:syz.0: about to withdraw this file system
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 0 UID: 0 PID: 5476 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
RIP: 0010:do_raw_spin_lock+0x73/0x2f0 kernel/locking/spinlock_debug.c:115
Code: c7 44 24 30 d0 83 a2 81 4c 8d 64 24 20 49 c1 ec 03 48 b8 f1 f1 f1 f1 f8 f3 f3 f3 49 89 04 14 4c 8d 77 04 4c 89 f0 48 c1 e8 03 <0f> b6 04 10 84 c0 0f 85 f3 01 00 00 41 8b 06 3d ad 4e ad de 0f 85
RSP: 0018:ffffc90003797a80 EFLAGS: 00010203
RAX: 0000000000000004 RBX: 0000000000000020 RCX: 0000000080000002
RDX: dffffc0000000000 RSI: ffffffff8c296400 RDI: 0000000000000020
RBP: ffffc90003797b30 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1007fdb805 R12: 1ffff920006f2f54
R13: 0000000000000000 R14: 0000000000000024 R15: dffffc0000000000
FS: 0000555585a45500(0000) GS:ffff88808c848000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000006cb000 CR3: 000000003e1b2000 CR4: 0000000000352ef0
Call Trace:
<TASK>
spin_lock include/linux/spinlock.h:342 [inline]
gfs2_glock_dq+0xbe/0xb40 fs/gfs2/glock.c:1598
gfs2_glock_dq_uninit+0x25/0xb0 fs/gfs2/glock.c:1656
gfs2_seek_data+0x176/0x250 fs/gfs2/inode.c:2246
gfs2_llseek+0x1c1/0x270 fs/gfs2/file.c:75
vfs_llseek fs/read_write.c:391 [inline]
ksys_lseek fs/read_write.c:404 [inline]
__do_sys_lseek fs/read_write.c:414 [inline]
__se_sys_lseek fs/read_write.c:412 [inline]
__x64_sys_lseek+0x14f/0x1e0 fs/read_write.c:412
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4dea99ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd2c1b0b78 EFLAGS: 00000246 ORIG_RAX: 0000000000000008
RAX: ffffffffffffffda RBX: 00007f4deac15fa0 RCX: 00007f4dea99ce59
RDX: 0000000000000003 RSI: 0000000000000006 RDI: 0000000000000005
RBP: 00007f4deaa32e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4deac15fac R14: 00007f4deac15fa0 R15: 00007f4deac15fa0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
RIP: 0010:do_raw_spin_lock+0x73/0x2f0 kernel/locking/spinlock_debug.c:115
Code: c7 44 24 30 d0 83 a2 81 4c 8d 64 24 20 49 c1 ec 03 48 b8 f1 f1 f1 f1 f8 f3 f3 f3 49 89 04 14 4c 8d 77 04 4c 89 f0 48 c1 e8 03 <0f> b6 04 10 84 c0 0f 85 f3 01 00 00 41 8b 06 3d ad 4e ad de 0f 85
RSP: 0018:ffffc90003797a80 EFLAGS: 00010203
RAX: 0000000000000004 RBX: 0000000000000020 RCX: 0000000080000002
RDX: dffffc0000000000 RSI: ffffffff8c296400 RDI: 0000000000000020
RBP: ffffc90003797b30 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1007fdb805 R12: 1ffff920006f2f54
R13: 0000000000000000 R14: 0000000000000024 R15: dffffc0000000000
FS: 0000555585a45500(0000) GS:ffff88808c848000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000006cb000 CR3: 000000003e1b2000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: c7 44 24 30 d0 83 a2 movl $0x81a283d0,0x30(%rsp)
7: 81
8: 4c 8d 64 24 20 lea 0x20(%rsp),%r12
d: 49 c1 ec 03 shr $0x3,%r12
11: 48 b8 f1 f1 f1 f1 f8 movabs $0xf3f3f3f8f1f1f1f1,%rax
18: f3 f3 f3
1b: 49 89 04 14 mov %rax,(%r12,%rdx,1)
1f: 4c 8d 77 04 lea 0x4(%rdi),%r14
23: 4c 89 f0 mov %r14,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 0f b6 04 10 movzbl (%rax,%rdx,1),%eax <-- trapping instruction
2e: 84 c0 test %al,%al
30: 0f 85 f3 01 00 00 jne 0x229
36: 41 8b 06 mov (%r14),%eax
39: 3d ad 4e ad de cmp $0xdead4ead,%eax
3e: 0f .byte 0xf
3f: 85 .byte 0x85
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2026-06-20 5:44 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
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2025-12-26 11:22 [syzbot] [gfs2?] general protection fault in gfs2_glock_dq (2) syzbot
2026-06-20 5:44 ` syzbot
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