rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (0 ticks this GP) idle=abe/1/0x4000000000000000 softirq=66336/66336 fqs=6
(detected by 1, t=10502 jiffies, g=122853, q=149)
============================================
WARNING: possible recursive locking detected
5.10.0-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.3/22815 is trying to acquire lock:
ffffffff8b79d898 (rcu_node_0){-.-.}-{2:2}, at: rcu_dump_cpu_stacks+0x9c/0x230 kernel/rcu/tree_stall.h:334
but task is already holding lock:
ffffffff8b79d898 (rcu_node_0){-.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:493 [inline]
ffffffff8b79d898 (rcu_node_0){-.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:652 [inline]
ffffffff8b79d898 (rcu_node_0){-.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3751 [inline]
ffffffff8b79d898 (rcu_node_0){-.-.}-{2:2}, at: rcu_sched_clock_irq.cold+0x2e2/0xf90 kernel/rcu/tree.c:2580
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rcu_node_0);
lock(rcu_node_0);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by syz-executor.3/22815:
#0: ffff88801a45f298 (&mm->mmap_lock#2){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88801a45f298 (&mm->mmap_lock#2){++++}-{3:3}, at: do_user_addr_fault+0x25f/0xc60 arch/x86/mm/fault.c:1334
#1: ffff88806b3e75b8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline]
#1: ffff88806b3e75b8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: wp_page_copy+0x623/0x2430 mm/memory.c:2880
#2: ffffffff8b79d898 (rcu_node_0){-.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:493 [inline]
#2: ffffffff8b79d898 (rcu_node_0){-.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:652 [inline]
#2: ffffffff8b79d898 (rcu_node_0){-.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3751 [inline]
#2: ffffffff8b79d898 (rcu_node_0){-.-.}-{2:2}, at: rcu_sched_clock_irq.cold+0x2e2/0xf90 kernel/rcu/tree.c:2580
stack backtrace:
CPU: 1 PID: 22815 Comm: syz-executor.3 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x107/0x163 lib/dump_stack.c:120
print_deadlock_bug kernel/locking/lockdep.c:2761 [inline]
check_deadlock kernel/locking/lockdep.c:2804 [inline]
validate_chain kernel/locking/lockdep.c:3595 [inline]
__lock_acquire.cold+0x115/0x3e6 kernel/locking/lockdep.c:4832
lock_acquire kernel/locking/lockdep.c:5437 [inline]
lock_acquire+0x29d/0x750 kernel/locking/lockdep.c:5402
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159
rcu_dump_cpu_stacks+0x9c/0x230 kernel/rcu/tree_stall.h:334
print_other_cpu_stall kernel/rcu/tree_stall.h:510 [inline]
check_cpu_stall kernel/rcu/tree_stall.h:652 [inline]
rcu_pending kernel/rcu/tree.c:3751 [inline]
rcu_sched_clock_irq.cold+0x804/0xf90 kernel/rcu/tree.c:2580
update_process_times+0x16d/0x200 kernel/time/timer.c:1782
tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1376
__run_hrtimer kernel/time/hrtimer.c:1519 [inline]
__hrtimer_run_queues+0x1c0/0xea0 kernel/time/hrtimer.c:1583
hrtimer_interrupt+0x334/0x960 kernel/time/hrtimer.c:1645
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
__sysvec_apic_timer_interrupt+0x146/0x550 arch/x86/kernel/apic/apic.c:1102
asm_call_irq_on_stack+0xf/0x20
__run_sysvec_on_irqstack arch/x86/include/asm/irq_stack.h:37 [inline]
run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:89 [inline]
sysvec_apic_timer_interrupt+0xbd/0x100 arch/x86/kernel/apic/apic.c:1096
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628
RIP: 0010:csd_lock_wait kernel/smp.c:227 [inline]
RIP: 0010:smp_call_function_single+0x1b0/0x4b0 kernel/smp.c:512
Code: 10 8b 7c 24 1c 48 8d 74 24 40 48 89 44 24 50 48 8b 44 24 08 48 89 44 24 58 e8 0c fb ff ff 41 89 c5 eb 07 e8 02 80 0b 00 f3 90 <44> 8b 64 24 48 31 ff 41 83 e4 01 44 89 e6 e8 0d 86 0b 00 45 85 e4
RSP: 0000:ffffc90007f179a0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff92000fe2f38 RCX: 0000000000000000
RDX: ffff8880676801c0 RSI: ffffffff8167c5ee RDI: 0000000000000003
RBP: ffffc90007f17a80 R08: 0000000000000000 R09: ffffffff8f5207b7
R10: ffffffff8167c603 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000008
smp_call_function_many_cond+0x27d/0x9e0 kernel/smp.c:648
on_each_cpu_cond_mask+0x50/0x160 kernel/smp.c:899
__flush_tlb_others arch/x86/include/asm/paravirt.h:74 [inline]
flush_tlb_others arch/x86/mm/tlb.c:829 [inline]
flush_tlb_mm_range+0x2af/0x3d0 arch/x86/mm/tlb.c:916
flush_tlb_page arch/x86/include/asm/tlbflush.h:235 [inline]
ptep_clear_flush+0x12b/0x160 mm/pgtable-generic.c:97
wp_page_copy+0x8dd/0x2430 mm/memory.c:2901
do_wp_page+0x3fe/0x1930 mm/memory.c:3145
handle_pte_fault mm/memory.c:4403 [inline]
__handle_mm_fault mm/memory.c:4520 [inline]
handle_mm_fault+0x3082/0x5760 mm/memory.c:4618
do_user_addr_fault+0x458/0xc60 arch/x86/mm/fault.c:1393
handle_page_fault arch/x86/mm/fault.c:1450 [inline]
exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1506
asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:580
RIP: 0033:0x410578
Code: d9 48 8b 47 78 48 83 f8 ff 0f 84 0b 01 00 00 48 8b 73 18 48 83 fe ff 74 29 48 81 fe e7 03 00 00 0f 87 5e 01 00 00 48 c1 e6 04 86 e0 80 19 01 01 48 89 86 e8 80 19 01 66 2e 0f 1f 84 00 00 00
RSP: 002b:00007ffeb16807b0 EFLAGS: 00010202
RAX: 0000000000000004 RBX: 000000000119c0d0 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000010 RDI: 000000000119c0d0
RBP: 000000000119c0d0 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffeb16808b0 R11: 0000000000000246 R12: 00000000000ecb03
R13: 00000000000ecad6 R14: 00000000000003e8 R15: 000000000119c0dc