rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=b9d/1/0x4000000000000000 softirq=11246/11246 fqs=21 (t=10500 jiffies g=11045 q=416) rcu: rcu_preempt kthread starved for 10449 jiffies! g11045 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:R running task stack:28696 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xb44/0x5960 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9023 Comm: syz-executor.0 Not tainted 5.15.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__unwind_start+0x2a/0x800 arch/x86/kernel/unwind_orc.c:628 Code: 41 57 49 89 ff 41 56 41 55 4d 8d 6f 28 41 54 49 89 d4 ba 60 00 00 00 55 48 89 f5 31 f6 53 48 89 cb 48 83 ec 18 e8 c6 8c 8a 00 <4c> 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f RSP: 0018:ffffc900054ff510 EFLAGS: 00000216 RAX: ffffc900054ff560 RBX: ffffc900054ff5e8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc900054ff5c0 RBP: ffff88807c865580 R08: 0000000000000001 R09: ffffc900054ff560 R10: fffff52000a9feb7 R11: 0000000000000000 R12: 0000000000000000 R13: ffffc900054ff588 R14: ffff88807c865580 R15: ffffc900054ff560 FS: 00007f027c1c2700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2c824000 CR3: 000000001b01c000 CR4: 0000000000350ef0 Call Trace: unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0x5c/0xe0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa4/0xd0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:591 [inline] tty_alloc_file drivers/tty/tty_io.c:187 [inline] tty_open+0x140/0x1000 drivers/tty/tty_io.c:2140 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4c8/0x11d0 fs/open.c:822 do_open fs/namei.c:3428 [inline] path_openat+0x1c9a/0x2740 fs/namei.c:3561 do_filp_open+0x1aa/0x400 fs/namei.c:3588 do_sys_openat2+0x16d/0x4d0 fs/open.c:1200 do_sys_open fs/open.c:1216 [inline] __do_sys_openat fs/open.c:1232 [inline] __se_sys_openat fs/open.c:1227 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1227 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+0x44/0xae RIP: 0033:0x7f027ec4ca39 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f027c1c2188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f027ed4ff60 RCX: 00007f027ec4ca39 RDX: 0000000000000802 RSI: 0000000020000840 RDI: ffffffffffffff9c RBP: 00007f027eca6c5f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff7866524f R14: 00007f027c1c2300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 9011 Comm: syz-executor.1 Not tainted 5.15.0-rc5-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+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 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:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3880 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2599 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1421 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c: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:__schedule+0xb4c/0x5960 kernel/sched/core.c:6166 Code: fa 48 c1 ea 03 80 3c 02 00 0f 85 70 4a 00 00 48 8b bd 40 ff ff ff 4c 89 63 10 4c 89 e6 e8 6c ad c8 f7 48 89 c7 e8 34 9a 18 f8 <48> 8b b5 e8 fe ff ff 48 b8 00 00 00 00 00 fc ff df 48 c7 04 06 00 RSP: 0018:ffffc9000547f738 EFLAGS: 00000202 RAX: 0000000000f360a1 RBX: 0000000000000001 RCX: 1ffffffff1adc9c1 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000547f888 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817d01d8 R11: 0000000000000000 R12: ffff8880b9d32500 R13: 0000000000000000 R14: ffffffff8b332020 R15: ffffffff8b332020 schedule+0xd3/0x270 kernel/sched/core.c:6366 tty_open+0x885/0x1000 drivers/tty/tty_io.c:2153 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4c8/0x11d0 fs/open.c:822 do_open fs/namei.c:3428 [inline] path_openat+0x1c9a/0x2740 fs/namei.c:3561 do_filp_open+0x1aa/0x400 fs/namei.c:3588 do_sys_openat2+0x16d/0x4d0 fs/open.c:1200 do_sys_open fs/open.c:1216 [inline] __do_sys_openat fs/open.c:1232 [inline] __se_sys_openat fs/open.c:1227 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1227 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+0x44/0xae RIP: 0033:0x7f900acd0a39 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9008246188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f900add3f60 RCX: 00007f900acd0a39 RDX: 0000000000000802 RSI: 0000000020000840 RDI: ffffffffffffff9c RBP: 00007f900ad2ac5f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd2b7a9f5f R14: 00007f9008246300 R15: 0000000000022000 sched: RT throttling activated ---------------- Code disassembly (best guess): 0: 41 57 push %r15 2: 49 89 ff mov %rdi,%r15 5: 41 56 push %r14 7: 41 55 push %r13 9: 4d 8d 6f 28 lea 0x28(%r15),%r13 d: 41 54 push %r12 f: 49 89 d4 mov %rdx,%r12 12: ba 60 00 00 00 mov $0x60,%edx 17: 55 push %rbp 18: 48 89 f5 mov %rsi,%rbp 1b: 31 f6 xor %esi,%esi 1d: 53 push %rbx 1e: 48 89 cb mov %rcx,%rbx 21: 48 83 ec 18 sub $0x18,%rsp 25: e8 c6 8c 8a 00 callq 0x8a8cf0 * 2a: 4c 89 ea mov %r13,%rdx <-- trapping instruction 2d: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 34: fc ff df 37: 48 c1 ea 03 shr $0x3,%rdx 3b: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 3f: 0f .byte 0xf