=============================
WARNING: suspicious RCU usage
6.9.0-rc4-next-20240418-syzkaller #0 Not tainted
-----------------------------
kernel/rcu/tree.c:276 Illegal rcu_softirq_qs() in RCU read-side critical section!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by ksoftirqd/0/16:
#0: ffffffff8e333ae0 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
#0: ffffffff8e333ae0 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:933 [inline]
#0: ffffffff8e333ae0 (rcu_read_lock_sched){....}-{1:2}, at: pfn_valid include/linux/mmzone.h:2022 [inline]
#0: ffffffff8e333ae0 (rcu_read_lock_sched){....}-{1:2}, at: __virt_addr_valid+0x183/0x520 arch/x86/mm/physaddr.c:65
stack backtrace:
CPU: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.9.0-rc4-next-20240418-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6712
rcu_softirq_qs+0xd9/0x370 kernel/rcu/tree.c:273
__do_softirq+0x5fd/0x980 kernel/softirq.c:568
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633
irq_exit_rcu+0x9/0x30 kernel/softirq.c:645
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:67 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:103 [inline]
RIP: 0010:lock_release+0x166/0x9f0 kernel/locking/lockdep.c:5770
Code: 00 00 4c 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 7c d5 88 00 4c 89 6c 24 50 48 c7 84 24 b0 00 00 00 00 00 00 00 9c <8f> 84 24 b0 00 00 00 42 80 3c 3b 00 74 08 4c 89 f7 e8 64 d4 88 00
RSP: 0018:ffffc90000157918 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff9200002af3a RCX: ffffffff8172d8f0
RDX: 0000000000000000 RSI: ffffffff8c1f8ba0 RDI: ffffffff8c1f8b60
RBP: ffffc90000157a48 R08: ffffffff8fabdf2f R09: 1ffffffff1f57be5
R10: dffffc0000000000 R11: fffffbfff1f57be6 R12: 1ffff9200002af30
R13: ffffffff81424043 R14: ffffc900001579d0 R15: dffffc0000000000
rcu_lock_release include/linux/rcupdate.h:339 [inline]
rcu_read_unlock_sched include/linux/rcupdate.h:954 [inline]
pfn_valid include/linux/mmzone.h:2032 [inline]
__virt_addr_valid+0x41e/0x520 arch/x86/mm/physaddr.c:65
kasan_addr_to_slab+0xd/0x80 mm/kasan/common.c:37
__kasan_record_aux_stack+0x11/0xc0 mm/kasan/generic.c:526
__call_rcu_common kernel/rcu/tree.c:3102 [inline]
call_rcu+0x167/0xa70 kernel/rcu/tree.c:3206
context_switch kernel/sched/core.c:5411 [inline]
__schedule+0x17f0/0x4a50 kernel/sched/core.c:6745
__schedule_loop kernel/sched/core.c:6822 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6837
smpboot_thread_fn+0x61e/0xa30 kernel/smpboot.c:160
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>
vkms_vblank_simulate: vblank timer overrun
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 4c 89 f3 mov %r14,%rbx
5: 48 c1 eb 03 shr $0x3,%rbx
9: 42 80 3c 3b 00 cmpb $0x0,(%rbx,%r15,1)
e: 74 08 je 0x18
10: 4c 89 f7 mov %r14,%rdi
13: e8 7c d5 88 00 call 0x88d594
18: 4c 89 6c 24 50 mov %r13,0x50(%rsp)
1d: 48 c7 84 24 b0 00 00 movq $0x0,0xb0(%rsp)
24: 00 00 00 00 00
29: 9c pushf
* 2a: 8f 84 24 b0 00 00 00 pop 0xb0(%rsp) <-- trapping instruction
31: 42 80 3c 3b 00 cmpb $0x0,(%rbx,%r15,1)
36: 74 08 je 0x40
38: 4c 89 f7 mov %r14,%rdi
3b: e8 64 d4 88 00 call 0x88d4a4