invalid opcode in jfs_evict_inode

invalid opcode in jfs_evict_inode

[sanan.hasanou]

Good day, dear maintainers,

We found a bug using a modified version of syzkaller.

Kernel Branch: 7.0-rc1
Kernel Config: <https://drive.google.com/open?id=1RsqMUgdFUMq9-iREK8DZCvDfjq0RWm5X>
Unfortunately, we don't have any reproducer for this bug yet.
Thank you!

Best regards,
Sanan Hasanov

Oops: invalid opcode: 0000 [#1] SMP KASAN
CPU: 0 UID: 0 PID: 9298 Comm: syz-executor Not tainted 7.0.0-rc1 #1 PREEMPT(full) 
Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:jfs_evict_inode+0x3c5/0x3d0 fs/jfs/inode.c:175
Code: fe e9 28 fe ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 63 fe ff ff 4c 89 f7 e8 d6 8c f8 fe e9 56 fe ff ff e8 ec c1 8e fe 90 <0f> 0b 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 0f 1f 44 00 00 55 48
RSP: 0018:ffffc9000411fa18 EFLAGS: 00010293
RAX: ffffffff83080354 RBX: ffff888026d35560 RCX: ffff88801a9dd700
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000411fa50 R08: ffffffff8ef0f1bf R09: 1ffffffff1de1e37
R10: dffffc0000000000 R11: fffffbfff1de1e38 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888026d35200 R15: ffff888026d35560
FS:  000055555f753500(0000) GS:ffff88809d305000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0923345d58 CR3: 000000004a9e7000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 evict+0x533/0x9e0 fs/inode.c:846
 dispose_list fs/inode.c:888 [inline]
 evict_inodes+0x713/0x7a0 fs/inode.c:942
 generic_shutdown_super+0xb2/0x2f0 fs/super.c:632
 kill_block_super+0x4d/0xa0 fs/super.c:1725
 deactivate_locked_super+0xc1/0x410 fs/super.c:476
 deactivate_super+0xb8/0xe0 fs/super.c:509
 cleanup_mnt+0x3d9/0x460 fs/namespace.c:1312
 __cleanup_mnt+0x22/0x30 fs/namespace.c:1319
 task_work_run+0x1d3/0x260 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0x179/0x510 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x22c/0x8a0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f4b1a30556b
Code: 3b 16 00 00 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 31 f6 e9 05 00 00 00 0f 1f 44 00 00 f3 0f 1e fa b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 b0 ff ff ff f7 d8
RSP: 002b:00007ffc90fb1cd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f4b1a3a70ee RCX: 00007f4b1a30556b
RDX: 00007f4b1a1b0ea1 RSI: 0000000000000009 RDI: 00007ffc90fb1d90
RBP: 00007ffc90fb1d90 R08: 0000000000000073 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc90fb2e60
R13: 00007f4b1a3a70ee R14: 0000000000000032 R15: 000000000001854e
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:jfs_evict_inode+0x3c5/0x3d0 fs/jfs/inode.c:175
Code: fe e9 28 fe ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 63 fe ff ff 4c 89 f7 e8 d6 8c f8 fe e9 56 fe ff ff e8 ec c1 8e fe 90 <0f> 0b 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 0f 1f 44 00 00 55 48
RSP: 0018:ffffc9000411fa18 EFLAGS: 00010293
RAX: ffffffff83080354 RBX: ffff888026d35560 RCX: ffff88801a9dd700
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000411fa50 R08: ffffffff8ef0f1bf R09: 1ffffffff1de1e37
R10: dffffc0000000000 R11: fffffbfff1de1e38 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888026d35200 R15: ffff888026d35560
FS:  000055555f753500(0000) GS:ffff88809d305000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055bc0d358110 CR3: 000000004a9e7000 CR4: 00000000000006f0

<<<<<<<<<<<<<<< tail report >>>>>>>>>>>>>>>

Re: invalid opcode in jfs_evict_inode

[Tetsuo Handa]

On 2026/06/19 7:24, sanan.hasanou@gmail.com wrote:
> Good day, dear maintainers,
> 
> We found a bug using a modified version of syzkaller.
> 
> Kernel Branch: 7.0-rc1
> Kernel Config: <https://drive.google.com/open?id=1RsqMUgdFUMq9-iREK8DZCvDfjq0RWm5X>
> Unfortunately, we don't have any reproducer for this bug yet.
> Thank you!
> 
> Best regards,
> Sanan Hasanov

Thank you.

This bug is known as one of daily top crashers, and there already is a reproducer.

https://syzkaller.appspot.com/bug?id=6cc491be132cfdce3fd4c75357d4606bed322b31