[syzbot] [jfs?] general protection fault in inode_set_ctime_current

syzbot
2025-10-24T23:10:29Z

Hello,

syzbot found the following issue on:

HEAD commit: 6fab32bb6508 MAINTAINERS: add Mark Brown as a linux-next m..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16bd2d2f980000
kernel config: https://syzkaller.appspot.com/x/.config?x=df98b4d1d5944c56
dashboard link: https://syzkaller.appspot.com/bug?extid=cd7590567cc388f064f3
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=155a8be2580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15078258580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-6fab32bb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b126dd4d891b/vmlinux-6fab32bb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ae26100863fd/bzImage-6fab32bb.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/6617e28639c8/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=125f8c92580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cd7590567cc388f064f3@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 32768
Oops: general protection fault, probably for non-canonical address 0xe00e9c0e000c60d6: 0000 [#1] SMP KASAN NOPTI
KASAN: maybe wild-memory-access in range [0x00750070006306b0-0x00750070006306b7]
CPU: 0 UID: 0 PID: 5495 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~bpo12+1 04/01/2014
RIP: 0010:timestamp_truncate fs/inode.c:2732 [inline]
RIP: 0010:inode_set_ctime_current+0xcf/0xb40 fs/inode.c:2774
Code: d8 48 c1 e8 03 48 89 44 24 30 42 80 3c 20 00 74 08 48 89 df e8 e2 67 e7 ff 4c 8b 3b 49 8d bf 40 06 00 00 48 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 d6 07 00 00 48 89 5c 24 20 41 8b 87 40
RSP: 0018:ffffc90002b4f600 EFLAGS: 00010202
RAX: 000ea00e000c60d6 RBX: ffff88801c1ab220 RCX: ffff8880002b0000
RDX: 0000000000000000 RSI: 187182c674eb3579 RDI: 00750070006306b2
RBP: ffffc90002b4f6f0 R08: ffffffff8f7cf377 R09: 1ffffffff1ef9e6e
R10: dffffc0000000000 R11: fffffbfff1ef9e6f R12: dffffc0000000000
R13: ffff88801c1abe60 R14: ffffc90002b4f660 R15: 0075007000630072
FS: 000055557920a500(0000) GS:ffff88808d733000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31463fff CR3: 0000000011599000 CR4: 0000000000352ef0
Call Trace:
<TASK>
jfs_create+0x7f7/0xa80 fs/jfs/namei.c:152
lookup_open fs/namei.c:3796 [inline]
open_last_lookups fs/namei.c:3895 [inline]
path_openat+0x14f4/0x3830 fs/namei.c:4131
do_filp_open+0x1fa/0x410 fs/namei.c:4161
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1463
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: 0033:0x7f3f1c98efc9
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:00007ffd9e448248 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f3f1cbe5fa0 RCX: 00007f3f1c98efc9
RDX: 000000000000275a RSI: 0000200000000140 RDI: ffffffffffffff9c
RBP: 00007f3f1ca11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3f1cbe5fa0 R14: 00007f3f1cbe5fa0 R15: 0000000000000004
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:timestamp_truncate fs/inode.c:2732 [inline]
RIP: 0010:inode_set_ctime_current+0xcf/0xb40 fs/inode.c:2774
Code: d8 48 c1 e8 03 48 89 44 24 30 42 80 3c 20 00 74 08 48 89 df e8 e2 67 e7 ff 4c 8b 3b 49 8d bf 40 06 00 00 48 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 d6 07 00 00 48 89 5c 24 20 41 8b 87 40
RSP: 0018:ffffc90002b4f600 EFLAGS: 00010202
RAX: 000ea00e000c60d6 RBX: ffff88801c1ab220 RCX: ffff8880002b0000
RDX: 0000000000000000 RSI: 187182c674eb3579 RDI: 00750070006306b2
RBP: ffffc90002b4f6f0 R08: ffffffff8f7cf377 R09: 1ffffffff1ef9e6e
R10: dffffc0000000000 R11: fffffbfff1ef9e6f R12: dffffc0000000000
R13: ffff88801c1abe60 R14: ffffc90002b4f660 R15: 0075007000630072
FS: 000055557920a500(0000) GS:ffff88808d733000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffabbbdc000 CR3: 0000000011599000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: d8 48 c1 fmuls -0x3f(%rax)
3: e8 03 48 89 44 call 0x4489480b
8: 24 30 and $0x30,%al
a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1)
f: 74 08 je 0x19
11: 48 89 df mov %rbx,%rdi
14: e8 e2 67 e7 ff call 0xffe767fb
19: 4c 8b 3b mov (%rbx),%r15
1c: 49 8d bf 40 06 00 00 lea 0x640(%r15),%rdi
23: 48 89 f8 mov %rdi,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax <-- trapping instruction
2f: 84 c0 test %al,%al
31: 0f 85 d6 07 00 00 jne 0x80d
37: 48 89 5c 24 20 mov %rbx,0x20(%rsp)
3c: 41 rex.B
3d: 8b .byte 0x8b
3e: 87 .byte 0x87
3f: 40 rex

---
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