invalid opcode in txUnlock

From: sanan . hasanou

Date: Thu Jun 18 2026 - 17:36:56 EST


Good day, dear maintainers,

We found a bug using a modified kernel configuration file used by syzbot.

We enhanced the coverage of the configuration file using our tool, klocalizer.

Kernel Branch: 7.0-rc1
Kernel Config: <https://drive.google.com/open?id=1RsqMUgdFUMq9-iREK8DZCvDfjq0RWm5X>
Thank you!

Best regards,
Sanan Hasanov

BUG at fs/jfs/jfs_txnmgr.c:932 assert(mp->nohomeok > 0)
Oops: invalid opcode: 0000 [#1] SMP KASAN
CPU: 0 UID: 0 PID: 109 Comm: jfsCommit 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:txUnlock+0xcdb/0xd20 fs/jfs/jfs_txnmgr.c:932
Code: 17 fe 90 0f 0b e8 85 6a 87 fe 48 c7 c7 a0 68 e8 8a 48 c7 c6 79 65 e8 8a ba a4 03 00 00 48 c7 c1 40 6e e8 8a e8 06 db 17 fe 90 <0f> 0b e8 5e 6a 87 fe 48 c7 c7 a0 68 e8 8a 48 c7 c6 79 65 e8 8a ba
RSP: 0018:ffffc9000220fc50 EFLAGS: 00010246
RAX: 0000000000000037 RBX: 0000000000000012 RCX: ded9116c2cc60f00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc9000220fcf0 R08: ffffc9000220f947 R09: 1ffff92000441f28
R10: dffffc0000000000 R11: fffff52000441f29 R12: 1ffff1100306f76a
R13: 0000000000000000 R14: ffff88801837bb50 R15: ffffc90001d72090
FS: 0000000000000000(0000) GS:ffff88809d305000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7e130dfb85 CR3: 0000000026fd0000 CR4: 00000000000006f0
Call Trace:
<TASK>
txLazyCommit fs/jfs/jfs_txnmgr.c:2683 [inline]
jfs_lazycommit+0x4fc/0x8a0 fs/jfs/jfs_txnmgr.c:2734
kthread+0x355/0x410 kernel/kthread.c:467
ret_from_fork+0x38c/0x9c0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:245
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:txUnlock+0xcdb/0xd20 fs/jfs/jfs_txnmgr.c:932
Code: 17 fe 90 0f 0b e8 85 6a 87 fe 48 c7 c7 a0 68 e8 8a 48 c7 c6 79 65 e8 8a ba a4 03 00 00 48 c7 c1 40 6e e8 8a e8 06 db 17 fe 90 <0f> 0b e8 5e 6a 87 fe 48 c7 c7 a0 68 e8 8a 48 c7 c6 79 65 e8 8a ba
RSP: 0018:ffffc9000220fc50 EFLAGS: 00010246
RAX: 0000000000000037 RBX: 0000000000000012 RCX: ded9116c2cc60f00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc9000220fcf0 R08: ffffc9000220f947 R09: 1ffff92000441f28
R10: dffffc0000000000 R11: fffff52000441f29 R12: 1ffff1100306f76a
R13: 0000000000000000 R14: ffff88801837bb50 R15: ffffc90001d72090
FS: 0000000000000000(0000) GS:ffff88809d305000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555592286a08 CR3: 0000000029675000 CR4: 00000000000006f0

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