From: syzbot <syzbot+b5ddc2aecb8d1b29c871@syzkaller.appspotmail.com>
To: linux-kernel@vger.kernel.org, luto@kernel.org,
peterz@infradead.org, syzkaller-bugs@googlegroups.com,
tglx@kernel.org
Subject: [syzbot] [kernel?] WARNING: locking bug in finish_task_switch (3)
Date: Thu, 10 Sep 2026 15:34:34 -0700 [thread overview]
Message-ID: <6aa3307a.6e6c5f9e.28f11f.003a.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 1fc5a74b108f Merge tag 'kmalloc_obj-v7.3-rc2' of git://git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14f2ccf9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=5e4e3a0e188a497e
dashboard link: https://syzkaller.appspot.com/bug?extid=b5ddc2aecb8d1b29c871
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8955e485c188/disk-1fc5a74b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a91efe973539/vmlinux-1fc5a74b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/92b415d78cae/bzImage-1fc5a74b.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b5ddc2aecb8d1b29c871@syzkaller.appspotmail.com
usb 9-1: Quirk or no altset; falling back to MIDI 1.0
usb 9-1: USB disconnect, device number 97
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(1)
WARNING: kernel/locking/lockdep.c:238 at hlock_class kernel/locking/lockdep.c:238 [inline], CPU#0: kworker/0:10/9284
WARNING: kernel/locking/lockdep.c:238 at check_wait_context kernel/locking/lockdep.c:4895 [inline], CPU#0: kworker/0:10/9284
WARNING: kernel/locking/lockdep.c:238 at __lock_acquire+0x584/0x2e50 kernel/locking/lockdep.c:5204, CPU#0: kworker/0:10/9284
Modules linked in:
CPU: 0 UID: 0 PID: 9284 Comm: kworker/0:10 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: sock_diag_events sock_diag_broadcast_destroy_work
RIP: 0010:hlock_class kernel/locking/lockdep.c:238 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4895 [inline]
RIP: 0010:__lock_acquire+0x58b/0x2e50 kernel/locking/lockdep.c:5204
Code: fa 18 00 74 04 31 c9 eb 2d 90 e8 00 91 37 03 85 c0 74 1c 83 3d 89 26 d7 0e 00 75 13 48 8d 3d 3c 2f da 0e 48 c7 c6 5e d9 59 8e <67> 48 0f b9 3a 90 31 c9 48 8b 3c 24 0f b6 81 c4 00 00 00 84 c0 0f
RSP: 0018:ffffc900034373b8 EFLAGS: 00010046
RAX: 0000000000000001 RBX: ffff88802cb369e0 RCX: ffff88802cb35dc0
RDX: 0000000040000000 RSI: ffffffff8e59d95e RDI: ffffffff907d5240
RBP: 0000000000000002 R08: ffffffff907a4983 R09: 1ffffffff20f4930
R10: dffffc0000000000 R11: fffffbfff20f4931 R12: 00000000ffffff05
R13: 0000000000000000 R14: ffff88802cb369e8 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff888124cd8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000024c030 CR3: 000000007442c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000400
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908
finish_lock_switch kernel/sched/core.c:5248 [inline]
finish_task_switch+0x16e/0xc60 kernel/sched/core.c:5369
context_switch kernel/sched/core.c:5523 [inline]
__schedule+0x17e3/0x58f0 kernel/sched/core.c:7270
preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7592
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x910 kernel/entry/common.c:167
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:679
RIP: 0010:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5913
Code: ff ff ff e8 20 39 41 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 72 64 f1 11 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 cf 3c 44 0a cc 48 8d 3d f7 35 da
RSP: 0018:ffffc90003437920 EFLAGS: 00000292
RAX: 4cc9e7c7ad94c500 RBX: 0000000000000001 RCX: 0000000000000046
RDX: ffffffff94482fa8 RSI: ffffffff8e6fd430 RDI: ffffffff8c6d9480
RBP: ffff88802cb35dc0 R08: 0000000000000008 R09: ffffffff96e17510
R10: 00000000ab51b954 R11: 000000009f2f398b R12: ffff888044880f60
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000246
lock_sock_fast include/net/sock.h:1744 [inline]
tcp_get_info+0x261/0x2b70 net/ipv4/tcp.c:4250
inet_diag_handler_get_info+0x481/0x700 net/ipv4/inet_diag.c:1030
sock_diag_broadcast_destroy_work+0x1f4/0x3d0 net/core/sock_diag.c:162
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
kthread+0x38b/0x480 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>
----------------
Code disassembly (best guess):
0: fa cli
1: 18 00 sbb %al,(%rax)
3: 74 04 je 0x9
5: 31 c9 xor %ecx,%ecx
7: eb 2d jmp 0x36
9: 90 nop
a: e8 00 91 37 03 call 0x337910f
f: 85 c0 test %eax,%eax
11: 74 1c je 0x2f
13: 83 3d 89 26 d7 0e 00 cmpl $0x0,0xed72689(%rip) # 0xed726a3
1a: 75 13 jne 0x2f
1c: 48 8d 3d 3c 2f da 0e lea 0xeda2f3c(%rip),%rdi # 0xeda2f5f
23: 48 c7 c6 5e d9 59 8e mov $0xffffffff8e59d95e,%rsi
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: 90 nop
30: 31 c9 xor %ecx,%ecx
32: 48 8b 3c 24 mov (%rsp),%rdi
36: 0f b6 81 c4 00 00 00 movzbl 0xc4(%rcx),%eax
3d: 84 c0 test %al,%al
3f: 0f .byte 0xf
---
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reply other threads:[~2026-09-10 22:34 UTC|newest]
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