=============================
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/1/24:
#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: 1 PID: 24 Comm: ksoftirqd/1 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:
__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
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:rcu_read_lock_sched include/linux/rcupdate.h:934 [inline]
RIP: 0010:pfn_valid include/linux/mmzone.h:2022 [inline]
RIP: 0010:__virt_addr_valid+0x1a4/0x520 arch/x86/mm/physaddr.c:65
Code: 23 00 4c 8d 35 00 00 00 00 48 c7 c7 e0 3a 33 8e 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 41 56 e8 50 71 30 00 48 83 c4 08 27 ef 43 0a 89 c3 31 ff 89 c6 e8 5c 21 54 00 85 db 74 10 e8 73
RSP: 0018:ffffc900001e7a58 EFLAGS: 00000282
RAX: 6c72c43ea82e0200 RBX: 0000000000000180 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: ffffffff8bcac4e0 RDI: ffffffff8c1f8bc0
RBP: dffffc0000000000 R08: ffffffff92f7b5a7 R09: 1ffffffff25ef6b4
R10: dffffc0000000000 R11: fffffbfff25ef6b5 R12: 0000000062145378
R13: 1ffff9200003cf64 R14: ffffffff81424043 R15: ffff88813fff9180
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
vkms_vblank_simulate: vblank timer overrun
vkms_vblank_simulate: vblank timer overrun
vkms_vblank_simulate: vblank timer overrun
----------------
Code disassembly (best guess):
0: 23 00 and (%rax),%eax
2: 4c 8d 35 00 00 00 00 lea 0x0(%rip),%r14 # 0x9
9: 48 c7 c7 e0 3a 33 8e mov $0xffffffff8e333ae0,%rdi
10: 31 f6 xor %esi,%esi
12: 31 d2 xor %edx,%edx
14: b9 02 00 00 00 mov $0x2,%ecx
19: 45 31 c0 xor %r8d,%r8d
1c: 45 31 c9 xor %r9d,%r9d
1f: 41 56 push %r14
21: e8 50 71 30 00 call 0x307176
26: 48 83 c4 08 add $0x8,%rsp
* 2a: e8 27 ef 43 0a call 0xa43ef56 <-- trapping instruction
2f: 89 c3 mov %eax,%ebx
31: 31 ff xor %edi,%edi
33: 89 c6 mov %eax,%esi
35: e8 5c 21 54 00 call 0x542196
3a: 85 db test %ebx,%ebx
3c: 74 10 je 0x4e
3e: e8 .byte 0xe8
3f: 73 .byte 0x73