rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (10500 ticks this GP) idle=cdb/1/0x4000000000000000 softirq=6263/6263 fqs=5250 (t=10502 jiffies g=5713 q=362) NMI backtrace for cpu 1 CPU: 1 PID: 4060 Comm: syz-executor376 Not tainted 5.17.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x57/0x7d lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x30/0xc0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x11f/0x170 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline] check_cpu_stall kernel/rcu/tree_stall.h:688 [inline] rcu_pending kernel/rcu/tree.c:3919 [inline] rcu_sched_clock_irq.cold+0x5c/0x759 kernel/rcu/tree.c:2617 update_process_times+0x13b/0x1c0 kernel/time/timer.c:1785 tick_sched_handle+0x6f/0x130 kernel/time/tick-sched.c:226 tick_sched_timer+0x132/0x210 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x18a/0xb00 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x2f5/0x780 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__mnt_want_write+0x85/0x230 fs/namespace.c:347 Code: 84 c0 74 08 3c 03 0f 8e 5d 01 00 00 8b 43 10 f6 c4 02 74 2e 48 b8 00 00 00 00 00 fc ff df 4c 89 e5 48 c1 ed 03 48 01 c5 f3 90 <0f> b6 45 00 84 c0 74 08 3c 03 0f 8e 3c 01 00 00 8b 43 10 f6 c4 02 RSP: 0018:ffffc90001b2fe00 EFLAGS: 00000202 RAX: 0000000000000220 RBX: ffff888020de36a0 RCX: 1ffffffff1e7f920 RDX: 1ffff110041bc6d6 RSI: ffffffff88cb9880 RDI: ffff888018506b58 RBP: ffffed10041bc6d6 R08: 0000000000000001 R09: ffffffff8e1f3167 R10: fffffbfff1c3e62c R11: 0000000000000000 R12: ffff888020de36b0 R13: ffff888020de36d0 R14: 0000000000000000 R15: 0000000000000000 mnt_want_write+0x103/0x310 fs/namespace.c:378 path_setxattr+0x9d/0x170 fs/xattr.c:593 __do_sys_lsetxattr fs/xattr.c:618 [inline] __se_sys_lsetxattr fs/xattr.c:614 [inline] __x64_sys_lsetxattr+0xb8/0x150 fs/xattr.c:614 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f1d0fa19cc9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1d0f9aa2f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd RAX: ffffffffffffffda RBX: 00007f1d0faa14b0 RCX: 00007f1d0fa19cc9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000600 RBP: 00007f1d0fa6f074 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e R13: 695f70756f72672c R14: 695f726573752c30 R15: 00007f1d0faa14b8 ---------------- Code disassembly (best guess): 0: 84 c0 test %al,%al 2: 74 08 je 0xc 4: 3c 03 cmp $0x3,%al 6: 0f 8e 5d 01 00 00 jle 0x169 c: 8b 43 10 mov 0x10(%rbx),%eax f: f6 c4 02 test $0x2,%ah 12: 74 2e je 0x42 14: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1b: fc ff df 1e: 4c 89 e5 mov %r12,%rbp 21: 48 c1 ed 03 shr $0x3,%rbp 25: 48 01 c5 add %rax,%rbp 28: f3 90 pause * 2a: 0f b6 45 00 movzbl 0x0(%rbp),%eax <-- trapping instruction 2e: 84 c0 test %al,%al 30: 74 08 je 0x3a 32: 3c 03 cmp $0x3,%al 34: 0f 8e 3c 01 00 00 jle 0x176 3a: 8b 43 10 mov 0x10(%rbx),%eax 3d: f6 c4 02 test $0x2,%ah