=============================
[ BUG: Invalid wait context ]
syzkaller #0 Not tainted
-----------------------------
udevd/5335 is trying to lock:
ffff888052945410 (&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}
2 locks held by udevd/5335:
#0: ffffffff8e33a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e33a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e33a0e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
#0: ffffffff8e33a0e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x2390 arch/x86/kernel/unwind_orc.c:479
#1: ffff888052945960 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#1: ffff888052945960 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#1: ffff888052945960 (&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: 5335 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
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+0x4dd/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:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x55/0xb0 kernel/rcu/tree.c:751
Code: 5d de 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 0c 4e 7e 00 48 c7 c3 98 8f c2 92 49 03 1e 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d d9 ef 1a 11 74 11 83 e0
RSP: 0018:ffffc9000d1d73f8 EFLAGS: 00000a06
RAX: 1ffff11003f865f3 RBX: ffff88801fc32f98 RCX: bfd6fd9ceecb2d00
RDX: ffffc9000d1d7501 RSI: ffffffff8c035060 RDI: ffffffff8c035020
RBP: dffffc0000000000 R08: ffffc9000d1d7bd0 R09: 0000000000000000
R10: ffffc9000d1d7538 R11: fffff52001a3aea9 R12: ffffc9000d1d7be0
R13: ffffc9000d1d0000 R14: ffffffff8dde5d10 R15: dffffc0000000000
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x1965/0x2390 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:330 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:356
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4191 [inline]
slab_alloc_node mm/slub.c:4240 [inline]
kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4247
lsm_file_alloc security/security.c:733 [inline]
security_file_alloc+0x34/0x330 security/security.c:2888
init_file+0x93/0x2f0 fs/file_table.c:159
alloc_empty_file+0x6e/0x1d0 fs/file_table.c:241
path_openat+0x107/0x3830 fs/namei.c:4032
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1e1b6a7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc438c7a40 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f1e1bd54880 RCX: 00007f1e1b6a7407
RDX: 0000000000080000 RSI: 00007ffc438c7bb0 RDI: ffffffffffffff9c
RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000560e139e77f5
R13: 0000560e139e77f5 R14: 0000000000000001 R15: 0000560e13a02140
----------------
Code disassembly (best guess):
0: 5d pop %rbp
1: de 8d 4c 89 f0 48 fimuls 0x48f0894c(%rbp)
7: c1 e8 03 shr $0x3,%eax
a: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1)
f: 74 08 je 0x19
11: 4c 89 f7 mov %r14,%rdi
14: e8 0c 4e 7e 00 call 0x7e4e25
19: 48 c7 c3 98 8f c2 92 mov $0xffffffff92c28f98,%rbx
20: 49 03 1e add (%r14),%rbx
23: 48 89 d8 mov %rbx,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax <-- trapping instruction
2f: 84 c0 test %al,%al
31: 75 34 jne 0x67
33: 8b 03 mov (%rbx),%eax
35: 65 ff 0d d9 ef 1a 11 decl %gs:0x111aefd9(%rip) # 0x111af015
3c: 74 11 je 0x4f
3e: 83 .byte 0x83
3f: e0 .byte 0xe0