rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=cf9/1/0x4000000000000000 softirq=45066/45066 fqs=1 (detected by 1, t=10504 jiffies, g=61497, q=144 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 18260 Comm: syz-executor.0 Not tainted 5.19.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0x262/0x5660 kernel/locking/lockdep.c:4988 Code: 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 14 02 84 d2 74 09 80 fa 03 0f 8e 3d 13 00 00 41 0f b7 44 24 20 49 8d 7c 24 08 <48> 89 fa 48 c1 ea 03 66 25 00 e0 09 c8 66 41 89 44 24 20 48 b8 00 RSP: 0018:ffffc90000007b80 EFLAGS: 00000046 RAX: 0000000000004b0a RBX: ffffffff8bd867e0 RCX: 0000000000000028 RDX: 0000000000000000 RSI: 0000000000000028 RDI: ffff888025628a90 RBP: 0000000000000000 R08: 1ffff11004ac5150 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888025628a88 R13: ffff888025628000 R14: 0000000000000002 R15: 0000000000000001 FS: 0000555555ae1400(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9128f08a00 CR3: 000000004a65d000 CR4: 0000000000350ef0 Call Trace: lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630 rcu_lock_acquire include/linux/rcupdate.h:269 [inline] rcu_read_lock include/linux/rcupdate.h:695 [inline] advance_sched+0x4a5/0x9a0 net/sched/sch_taprio.c:768 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x30 kernel/rcu/update.c:280 Code: c7 e0 78 cc 89 e8 20 0d 00 00 65 c7 05 4d 61 8b 76 00 00 00 00 eb bc e8 4e fb ff ff eb bc cc cc cc cc cc cc cc cc cc cc cc cc <8b> 05 96 61 44 04 85 c0 74 21 8b 05 2c 94 44 04 85 c0 74 17 65 48 RSP: 0018:ffffc9000d5c7d20 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff815e52e1 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff8dbb7850 RBP: 1ffff92001ab8fa9 R08: 0000000000000000 R09: ffffffff8dbb7857 R10: fffffbfff1b76f0a R11: 0000000000000001 R12: 0000000000000001 R13: ffffffff81dbd175 R14: 0000000000000002 R15: ffff888048981100 rcu_read_lock_held_common kernel/rcu/update.c:104 [inline] rcu_read_lock_sched_held+0xd/0x70 kernel/rcu/update.c:123 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x560/0x780 kernel/locking/lockdep.c:5676 rcu_lock_release include/linux/rcupdate.h:274 [inline] rcu_read_unlock include/linux/rcupdate.h:728 [inline] dput+0x1a3/0xdb0 fs/dcache.c:901 path_put fs/namei.c:558 [inline] done_path_create fs/namei.c:3798 [inline] do_symlinkat+0x166/0x2e0 fs/namei.c:4373 __do_sys_symlinkat fs/namei.c:4387 [inline] __se_sys_symlinkat fs/namei.c:4384 [inline] __x64_sys_symlinkat+0x93/0xc0 fs/namei.c:4384 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f9128e88a17 Code: 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0a 01 00 00 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:00007ffd81ff6ec8 EFLAGS: 00000202 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9128e88a17 RDX: 00007f9128ee3159 RSI: 00000000ffffff9c RDI: 00007ffd81ff6f90 RBP: 0000000000000001 R08: 0000000000004000 R09: 00007ffd81ff6d60 R10: 00007ffd81ff6c17 R11: 0000000000000202 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffd81ff6f90 rcu: rcu_preempt kthread timer wakeup didn't happen for 10500 jiffies! g61497 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=30897 rcu: rcu_preempt kthread starved for 10501 jiffies! g61497 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack:28008 pid: 17 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5116 [inline] __schedule+0xa00/0x4b30 kernel/sched/core.c:6428 schedule+0xd2/0x1f0 kernel/sched/core.c:6500 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1999 ---------------- Code disassembly (best guess): 0: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 7: fc ff df a: 48 c1 ea 03 shr $0x3,%rdx e: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx 12: 84 d2 test %dl,%dl 14: 74 09 je 0x1f 16: 80 fa 03 cmp $0x3,%dl 19: 0f 8e 3d 13 00 00 jle 0x135c 1f: 41 0f b7 44 24 20 movzwl 0x20(%r12),%eax 25: 49 8d 7c 24 08 lea 0x8(%r12),%rdi * 2a: 48 89 fa mov %rdi,%rdx <-- trapping instruction 2d: 48 c1 ea 03 shr $0x3,%rdx 31: 66 25 00 e0 and $0xe000,%ax 35: 09 c8 or %ecx,%eax 37: 66 41 89 44 24 20 mov %ax,0x20(%r12) 3d: 48 rex.W 3e: b8 .byte 0xb8