=============================
[ BUG: Invalid wait context ]
6.16.0-next-20250808-syzkaller #0 Not tainted
-----------------------------
kdevtmpfs/26 is trying to lock:
ffff88802c249410 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x1fb/0x9b0 arch/x86/kvm/xen.c:1820
other info that might help us debug this:
context-{2:2}
4 locks held by kdevtmpfs/26:
#0: ffff8881404c8950 (&type->i_mutex_dir_key/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline]
#0: ffff8881404c8950 (&type->i_mutex_dir_key/1){+.+.}-{4:4}, at: __kern_path_locked+0x13f/0x260 fs/namei.c:2759
#1: ffff888148c00828 (&lockref->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
#1: ffff888148c00828 (&lockref->lock){+.+.}-{3:3}, at: __dentry_kill+0x2cf/0x660 fs/dcache.c:680
#2: ffffffff8e539ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#2: ffffffff8e539ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#2: ffffffff8e539ee0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
#2: ffffffff8e539ee0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x2390 arch/x86/kernel/unwind_orc.c:479
#3: ffff88802c249960 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#3: ffff88802c249960 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#3: ffff88802c249960 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x1c3/0x9b0 arch/x86/kvm/xen.c:1818
stack backtrace:
CPU: 0 UID: 0 PID: 26 Comm: kdevtmpfs Not tainted 6.16.0-next-20250808-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_lock_invalid_wait_context kernel/locking/lockdep.c:4830 [inline]
check_wait_context kernel/locking/lockdep.c:4902 [inline]
__lock_acquire+0xbcb/0xd20 kernel/locking/lockdep.c:5187
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
_raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236
kvm_xen_set_evtchn_fast+0x1fb/0x9b0 arch/x86/kvm/xen.c:1820
xen_timer_callback+0x109/0x220 arch/x86/kvm/xen.c:140
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x4e0/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 9b a2 46 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90000a174b8 EFLAGS: 00000206
RAX: aa4a8d882ff45a00 RBX: 0000000000000000 RCX: aa4a8d882ff45a00
RDX: 0000000000000000 RSI: ffffffff8de84cf9 RDI: ffffffff8c04d480
RBP: ffffffff81731195 R08: 0000000000000000 R09: ffffffff81731195
R10: ffffc90000a17678 R11: ffffffff81ac90a0 R12: 0000000000000002
R13: ffffffff8e539ee0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
__call_rcu_common kernel/rcu/tree.c:3123 [inline]
call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3243
__dentry_kill+0x4d2/0x660 fs/dcache.c:688
dput+0x19f/0x2b0 fs/dcache.c:911
handle_remove drivers/base/devtmpfs.c:352 [inline]
handle drivers/base/devtmpfs.c:391 [inline]
devtmpfs_work_loop+0x495/0xd20 drivers/base/devtmpfs.c:404
devtmpfsd+0x4d/0x50 drivers/base/devtmpfs.c:446
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 00 add %al,(%rax)
4: 9c pushf
5: 8f 44 24 30 pop 0x30(%rsp)
9: f7 44 24 30 00 02 00 testl $0x200,0x30(%rsp)
10: 00
11: 0f 85 cd 00 00 00 jne 0xe4
17: f7 44 24 08 00 02 00 testl $0x200,0x8(%rsp)
1e: 00
1f: 74 01 je 0x22
21: fb sti
22: 65 48 8b 05 9b a2 46 mov %gs:0x1146a29b(%rip),%rax # 0x1146a2c5
29: 11
* 2a: 48 3b 44 24 58 cmp 0x58(%rsp),%rax <-- trapping instruction
2f: 0f 85 f2 00 00 00 jne 0x127
35: 48 83 c4 60 add $0x60,%rsp
39: 5b pop %rbx
3a: 41 5c pop %r12
3c: 41 5d pop %r13
3e: 41 5e pop %r14