=============================
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:
__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:debug_lockdep_rcu_enabled+0xd/0x40 kernel/rcu/update.c:320
Code: f5 90 0f 0b 90 90 90 eb c6 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d 77 b0 25 04 00 <74> 1e 83 3d d6 e2 25 04 00 74 15 65 48 8b 0c 25 00 d5 03 00 31 c0
RSP: 0018:ffffc90000157a50 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000080 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: ffffffff8bcac4e0 RDI: ffffffff8c1f8bc0
RBP: dffffc0000000000 R08: ffffffff92f7b5a7 R09: 1ffffffff25ef6b4
R10: dffffc0000000000 R11: fffffbfff25ef6b5 R12: 00000000203a5378
R13: 1ffff9200002af64 R14: ffffffff81424043 R15: ffff88813fff9080
rcu_read_lock_sched include/linux/rcupdate.h:934 [inline]
pfn_valid include/linux/mmzone.h:2022 [inline]
__virt_addr_valid+0x1a9/0x520 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
vkms_vblank_simulate: vblank timer overrun
vkms_vblank_simulate: vblank timer overrun
vkms_vblank_simulate: vblank timer overrun
----------------
Code disassembly (best guess):
0: f5 cmc
1: 90 nop
2: 0f 0b ud2
4: 90 nop
5: 90 nop
6: 90 nop
7: eb c6 jmp 0xffffffcf
9: 0f 1f 40 00 nopl 0x0(%rax)
d: 90 nop
e: 90 nop
f: 90 nop
10: 90 nop
11: 90 nop
12: 90 nop
13: 90 nop
14: 90 nop
15: 90 nop
16: 90 nop
17: 90 nop
18: 90 nop
19: 90 nop
1a: 90 nop
1b: 90 nop
1c: 90 nop
1d: f3 0f 1e fa endbr64
21: 31 c0 xor %eax,%eax
23: 83 3d 77 b0 25 04 00 cmpl $0x0,0x425b077(%rip) # 0x425b0a1
* 2a: 74 1e je 0x4a <-- trapping instruction
2c: 83 3d d6 e2 25 04 00 cmpl $0x0,0x425e2d6(%rip) # 0x425e309
33: 74 15 je 0x4a
35: 65 48 8b 0c 25 00 d5 mov %gs:0x3d500,%rcx
3c: 03 00
3e: 31 c0 xor %eax,%eax