Re: [syzbot] [edac?] general protection fault in detach_timer (3)

From: syzbot

Date: Tue Sep 01 2026 - 04:30:43 EST


Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in __set_cpus_allowed_ptr_locked

------------[ cut here ]------------
!pending
WARNING: kernel/sched/core.c:3057 at affine_move_task kernel/sched/core.c:3057 [inline], CPU#0: irq/33-virtio1-/1193
WARNING: kernel/sched/core.c:3057 at __set_cpus_allowed_ptr_locked+0x10ff/0x19c0 kernel/sched/core.c:3190, CPU#0: irq/33-virtio1-/1193
Modules linked in:
CPU: 0 UID: 0 PID: 1193 Comm: irq/33-virtio1- Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:affine_move_task kernel/sched/core.c:3057 [inline]
RIP: 0010:__set_cpus_allowed_ptr_locked+0x10ff/0x19c0 kernel/sched/core.c:3190
Code: cf ff ff 48 8b 5c 24 18 48 8d 7b 08 e8 5a 93 09 00 e9 2e fe ff ff 90 0f 0b 90 e9 74 f3 ff ff e8 57 eb 9d ff e9 dd f8 ff ff 90 <0f> 0b 90 48 8b 3c 24 48 8b 74 24 08 48 8b 54 24 10 e8 2b cf ff ff
RSP: 0018:ffffc9000712f900 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff8880268e84b8 RCX: ffffffff81950d8b
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff8880268e84b0
RBP: ffffc9000712fb10 R08: ffff8880268e84b7 R09: 1ffff11004d1d096
R10: dffffc0000000000 R11: ffffed1004d1d097 R12: 1ffff11004d1d097
R13: 1ffff92000e25f28 R14: ffff8880268e84b0 R15: 0000000000000004
FS: 0000000000000000(0000) GS:ffff888125be1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555568e077b8 CR3: 000000003c6c2000 CR4: 00000000003526f0
Call Trace:
<TASK>
__set_cpus_allowed_ptr kernel/sched/core.c:3222 [inline]
___migrate_enable+0x19c/0x1f0 kernel/sched/core.c:2486
__migrate_enable include/linux/sched.h:2471 [inline]
migrate_enable include/linux/sched.h:2520 [inline]
__local_bh_enable+0x21c/0x2f0 kernel/softirq.c:273
__local_bh_enable_ip+0x19f/0x2b0 kernel/softirq.c:328
local_bh_enable include/linux/bottom_half.h:33 [inline]
irq_forced_thread_fn+0xe9/0x120 kernel/irq/manage.c:1169
irq_thread+0x455/0x690 kernel/irq/manage.c:1272
kthread+0x38b/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>


Tested on:

commit: 8ff706df x86/mce: Prevent polling timer rearm across t..
git tree: https://github.com/yutao-intel/linux.git fix-edac-v2
console output: https://syzkaller.appspot.com/x/log.txt?x=12f18779580000
kernel config: https://syzkaller.appspot.com/x/.config?x=e618aabdc2dca7e6
dashboard link: https://syzkaller.appspot.com/bug?extid=edc6b57cbed1fb72d0f9
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

Note: no patches were applied.