From: syzbot <syzbot+919877893c9d28162dc2@syzkaller.appspotmail.com>
To: bp@alien8.de, dave.hansen@linux.intel.com, dwmw2@infradead.org,
hpa@zytor.com, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, mingo@redhat.com, paul@xen.org,
pbonzini@redhat.com, seanjc@google.com,
syzkaller-bugs@googlegroups.com, tglx@linutronix.de,
x86@kernel.org
Subject: Re: [syzbot] [kvm?] WARNING: locking bug in kvm_xen_set_evtchn_fast
Date: Sat, 23 Nov 2024 05:17:19 -0800 [thread overview]
Message-ID: <6741d5df.050a0220.1cc393.0011.GAE@google.com> (raw)
In-Reply-To: <673f4bbc.050a0220.3c9d61.0174.GAE@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: 06afb0f36106 Merge tag 'trace-v6.13' of git://git.kernel.o..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=17ff7930580000
kernel config: https://syzkaller.appspot.com/x/.config?x=95b76860fd16c857
dashboard link: https://syzkaller.appspot.com/bug?extid=919877893c9d28162dc2
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=142981c0580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1371975f980000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/49111529582a/disk-06afb0f3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f04577ad9add/vmlinux-06afb0f3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b352b4fae995/bzImage-06afb0f3.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+919877893c9d28162dc2@syzkaller.appspotmail.com
=============================
[ BUG: Invalid wait context ]
6.12.0-syzkaller-07834-g06afb0f36106 #0 Not tainted
-----------------------------
kworker/0:1/9 is trying to lock:
ffffc90003bca460 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x1ee/0xa00 arch/x86/kvm/xen.c:1755
other info that might help us debug this:
context-{2:2}
6 locks held by kworker/0:1/9:
#0: ffff888144a92148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
#0: ffff888144a92148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
#1: ffffc900000e7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
#1: ffffc900000e7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
#2: ffff888145711190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline]
#2: ffff888145711190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5849
#3: ffffffff8e817de0 (console_lock){+.+.}-{0:0}, at: dev_vprintk_emit+0x2ae/0x330 drivers/base/core.c:4942
#4: ffffffff8e8179f0 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:342 [inline]
#4: ffffffff8e8179f0 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:297 [inline]
#4: ffffffff8e8179f0 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline]
#4: ffffffff8e8179f0 (console_srcu){....}-{0:0}, at: console_flush_all+0x1a3/0xeb0 kernel/printk/printk.c:3187
#5: ffffc90003bca8c8 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:158 [inline]
#5: ffffc90003bca8c8 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:249 [inline]
#5: ffffc90003bca8c8 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x1bb/0xa00 arch/x86/kvm/xen.c:1753
stack backtrace:
CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.12.0-syzkaller-07834-g06afb0f36106 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: usb_hub_wq hub_event
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_lock_invalid_wait_context kernel/locking/lockdep.c:4826 [inline]
check_wait_context kernel/locking/lockdep.c:4898 [inline]
__lock_acquire+0x15a8/0x2100 kernel/locking/lockdep.c:5176
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
__raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
_raw_read_lock_irqsave+0xdd/0x130 kernel/locking/spinlock.c:236
kvm_xen_set_evtchn_fast+0x1ee/0xa00 arch/x86/kvm/xen.c:1755
xen_timer_callback+0x1a0/0x380 arch/x86/kvm/xen.c:140
__run_hrtimer kernel/time/hrtimer.c:1739 [inline]
__hrtimer_run_queues+0x551/0xd50 kernel/time/hrtimer.c:1803
hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1865
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:console_flush_all+0x996/0xeb0
Code: 48 21 c3 0f 85 16 02 00 00 e8 66 aa 20 00 4c 8b 7c 24 10 4d 85 f6 75 07 e8 57 aa 20 00 eb 06 e8 50 aa 20 00 fb 48 8b 5c 24 18 <48> 8b 44 24 30 42 80 3c 28 00 74 08 48 89 df e8 76 61 8b 00 4c 8b
RSP: 0018:ffffc900000e7000 EFLAGS: 00000293
RAX: ffffffff8174a2e0 RBX: ffffffff8f17fa58 RCX: ffff88801bef8000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900000e71b0 R08: ffffffff8174a2b7 R09: 1ffffffff285cb10
R10: dffffc0000000000 R11: fffffbfff285cb11 R12: ffffffff8f17fa00
R13: dffffc0000000000 R14: 0000000000000200 R15: ffffc900000e7200
__console_flush_and_unlock kernel/printk/printk.c:3269 [inline]
console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309
vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432
dev_vprintk_emit+0x2ae/0x330 drivers/base/core.c:4942
dev_printk_emit+0xdd/0x120 drivers/base/core.c:4953
_dev_info+0x122/0x170 drivers/base/core.c:5011
show_string drivers/usb/core/hub.c:2357 [inline]
announce_device drivers/usb/core/hub.c:2375 [inline]
usb_new_device+0xd02/0x19a0 drivers/usb/core/hub.c:2632
hub_port_connect drivers/usb/core/hub.c:5521 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
port_event drivers/usb/core/hub.c:5821 [inline]
hub_event+0x2d6d/0x5150 drivers/usb/core/hub.c:5903
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
worker_thread+0x870/0xd30 kernel/workqueue.c:3391
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
----------------
Code disassembly (best guess):
0: 48 21 c3 and %rax,%rbx
3: 0f 85 16 02 00 00 jne 0x21f
9: e8 66 aa 20 00 call 0x20aa74
e: 4c 8b 7c 24 10 mov 0x10(%rsp),%r15
13: 4d 85 f6 test %r14,%r14
16: 75 07 jne 0x1f
18: e8 57 aa 20 00 call 0x20aa74
1d: eb 06 jmp 0x25
1f: e8 50 aa 20 00 call 0x20aa74
24: fb sti
25: 48 8b 5c 24 18 mov 0x18(%rsp),%rbx
* 2a: 48 8b 44 24 30 mov 0x30(%rsp),%rax <-- trapping instruction
2f: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
34: 74 08 je 0x3e
36: 48 89 df mov %rbx,%rdi
39: e8 76 61 8b 00 call 0x8b61b4
3e: 4c rex.WR
3f: 8b .byte 0x8b
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
next prev parent reply other threads:[~2024-11-23 13:17 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-21 15:03 [syzbot] [kvm?] WARNING: locking bug in kvm_xen_set_evtchn_fast syzbot
2024-11-23 13:17 ` syzbot [this message]
2024-11-23 23:32 ` Hillf Danton
2024-11-26 14:24 ` syzbot
2024-11-26 14:49 ` David Woodhouse
2024-11-26 15:03 ` Sebastian Andrzej Siewior
2024-11-26 16:26 ` David Woodhouse
2026-03-15 13:58 ` Forwarded: syzbot
2026-03-15 15:00 ` Forwarded: (No Subject) syzbot
2026-03-15 15:07 ` syzbot
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