From: syzbot <syzbot+8ce83fdb28edc2204e0d@syzkaller.appspotmail.com>
To: bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com,
linux-kernel@vger.kernel.org, mingo@redhat.com,
syzkaller-bugs@googlegroups.com, tglx@kernel.org,
x86@kernel.org
Subject: [syzbot] [kernel?] WARNING in native_smp_send_reschedule
Date: Thu, 03 Sep 2026 06:45:22 -0700 [thread overview]
Message-ID: <6a9979f2.0b659fcc.16ebfd.0004.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 08dbfad3f504 Merge tag 'for-linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13fa9379580000
kernel config: https://syzkaller.appspot.com/x/.config?x=85bc5cc2fc7394d9
dashboard link: https://syzkaller.appspot.com/bug?extid=8ce83fdb28edc2204e0d
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
userspace arch: i386
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-08dbfad3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8c91bd969338/vmlinux-08dbfad3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c17b532c72dd/bzImage-08dbfad3.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8ce83fdb28edc2204e0d@syzkaller.appspotmail.com
------------[ cut here ]------------
sched: Unexpected reschedule of offline CPU#3!
WARNING: arch/x86/kernel/apic/ipi.c:71 at native_smp_send_reschedule+0x4d/0x60 arch/x86/kernel/apic/ipi.c:71, CPU#2: kworker/u32:4/5842
Modules linked in:
CPU: 2 UID: 0 PID: 5842 Comm: kworker/u32:4 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
Workqueue: netns cleanup_net
RIP: 0010:native_smp_send_reschedule+0x4f/0x60 arch/x86/kernel/apic/ipi.c:71
Code: b0 c6 00 48 0f a3 2d a8 86 8e 0f 73 14 89 df be fd 00 00 00 5b 5d e9 a0 2a 01 00 90 0f 0b 90 eb c7 48 8d 3d 63 3f 91 0f 89 de <67> 48 0f b9 3a 5b 5d e9 05 b6 19 0a 0f 1f 44 00 00 90 90 90 90 90
RSP: 0018:ffffc9000617ee40 EFLAGS: 00010046
RAX: 0000000000000001 RBX: 0000000000000003 RCX: ffffffff81b69fa8
RDX: 0000000000000001 RSI: 0000000000000003 RDI: ffffffff9147df30
RBP: 0000000000000003 R08: 0000000000000000 R09: fffffbfff228a4cb
R10: ffffffff9145265f R11: 0000000000000003 R12: 0000000000000004
R13: 1ffff92000c2fdcc R14: ffffc9000617ee80 R15: 0000000000000010
FS: 0000000000000000(0000) GS:ffff888096b67000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a33142b090 CR3: 000000000eb96000 CR4: 0000000000350ef0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
arch_smp_send_reschedule arch/x86/include/asm/smp.h:90 [inline]
__resched_curr+0x2db/0x500 kernel/sched/core.c:1225
wakeup_preempt+0xd0/0x400 kernel/sched/core.c:2301
ttwu_do_activate+0x1ad/0x800 kernel/sched/core.c:3835
ttwu_queue kernel/sched/core.c:4087 [inline]
try_to_wake_up+0xcf0/0x1c90 kernel/sched/core.c:4425
cpu_stop_queue_work+0x271/0x340 kernel/stop_machine.c:108
stop_one_cpu_nowait+0xe8/0x160 kernel/stop_machine.c:387
sched_balance_rq+0x317c/0x48b0 kernel/sched/fair.c:13661
sched_balance_newidle kernel/sched/fair.c:14627 [inline]
pick_task_fair+0xb6b/0x1e00 kernel/sched/fair.c:10073
__pick_next_task+0x105/0x710 kernel/sched/core.c:6159
pick_next_task kernel/sched/core.c:6257 [inline]
__schedule+0x57f/0x6920 kernel/sched/core.c:7185
__schedule_loop kernel/sched/core.c:7347 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7362
schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
kthread_stop+0x18e/0x630 kernel/kthread.c:760
rxrpc_unuse_local+0x107/0x140 net/rxrpc/local_object.c:409
rxrpc_release_sock net/rxrpc/af_rxrpc.c:967 [inline]
rxrpc_release+0x384/0x6a0 net/rxrpc/af_rxrpc.c:994
__sock_release net/socket.c:735 [inline]
sock_release+0x91/0x1c0 net/socket.c:763
afs_close_socket+0x24b/0x410 fs/afs/rxrpc.c:154
afs_net_exit+0x93/0x150 fs/afs/main.c:149
ops_exit_list net/core/net_namespace.c:200 [inline]
ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:253
cleanup_net+0x499/0x920 net/core/net_namespace.c:706
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3387
process_scheduled_works kernel/workqueue.c:3470 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3551
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
----------------
Code disassembly (best guess):
0: b0 c6 mov $0xc6,%al
2: 00 48 0f add %cl,0xf(%rax)
5: a3 2d a8 86 8e 0f 73 movabs %eax,0x8914730f8e86a82d
c: 14 89
e: df be fd 00 00 00 fistpll 0xfd(%rsi)
14: 5b pop %rbx
15: 5d pop %rbp
16: e9 a0 2a 01 00 jmp 0x12abb
1b: 90 nop
1c: 0f 0b ud2
1e: 90 nop
1f: eb c7 jmp 0xffffffe8
21: 48 8d 3d 63 3f 91 0f lea 0xf913f63(%rip),%rdi # 0xf913f8b
28: 89 de mov %ebx,%esi
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: 5b pop %rbx
30: 5d pop %rbp
31: e9 05 b6 19 0a jmp 0xa19b63b
36: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
3b: 90 nop
3c: 90 nop
3d: 90 nop
3e: 90 nop
3f: 90 nop
---
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reply other threads:[~2026-09-03 13:45 UTC|newest]
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