INFO: rcu_preempt self-detected stall on CPU 1-...: (1 GPs behind) idle=d02/140000000000002/0 softirq=25372/25373 fqs=2 (t=10500 jiffies g=4635 c=4634 q=406) rcu_preempt kthread starved for 10493 jiffies! g4635 c4634 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 rcu_preempt R running task 29984 8 2 0x80000000 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x43c/0xe40 kernel/time/timer.c:1746 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 NMI backtrace for cpu 1 CPU: 1 PID: 12006 Comm: syz-executor.4 Not tainted 4.14.173-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x13e/0x194 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:158 [inline] rcu_dump_cpu_stacks+0x16d/0x1b8 kernel/rcu/tree.c:1396 print_cpu_stall kernel/rcu/tree.c:1542 [inline] check_cpu_stall kernel/rcu/tree.c:1610 [inline] __rcu_pending kernel/rcu/tree.c:3390 [inline] rcu_pending kernel/rcu/tree.c:3452 [inline] rcu_check_callbacks.cold+0x490/0xdaa kernel/rcu/tree.c:2792 update_process_times+0x29/0x60 kernel/time/timer.c:1590 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165 tick_sched_timer+0x3e/0x120 kernel/time/tick-sched.c:1223 __run_hrtimer kernel/time/hrtimer.c:1223 [inline] __hrtimer_run_queues+0x25c/0xbb0 kernel/time/hrtimer.c:1287 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline] smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:skb_put+0xad/0x1a0 net/core/skbuff.c:1695 RSP: 0018:ffff8880aeb07c48 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000000 RBX: 00000000000000b0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000020 RDI: ffff888093f2e104 RBP: ffff888093f2e080 R08: ffffed10127e5c29 R09: ffff8880a858c2c0 R10: ffffed10150b185c R11: ffff8880a858c2e3 R12: 0000000000000020 R13: ffff8880a858c0b0 R14: ffff888093f2e148 R15: ffff8880aeb07cb8 aoecmd_cfg_pkts drivers/block/aoe/aoecmd.c:432 [inline] aoecmd_cfg+0x173/0x570 drivers/block/aoe/aoecmd.c:1392 discover_timer drivers/block/aoe/aoemain.c:44 [inline] discover_timer+0xc5/0x160 drivers/block/aoe/aoemain.c:21 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279 expire_timers kernel/time/timer.c:1318 [inline] __run_timers kernel/time/timer.c:1636 [inline] __run_timers kernel/time/timer.c:1604 [inline] run_timer_softirq+0x52a/0x1390 kernel/time/timer.c:1649 __do_softirq+0x254/0x9bf kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x15b/0x1a0 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:unwind_next_frame+0xbbc/0x17a0 arch/x86/kernel/unwind_orc.c:498 RSP: 0018:ffff88805b5cf0a0 EFLAGS: 00000296 ORIG_RAX: ffffffffffffff10 RAX: ffff88805b5d0000 RBX: ffff88805b5cf150 RCX: 0000000000000001 RDX: 1ffff1100b6b9e2c RSI: 0000000000000000 RDI: ffff88805b5cf160 RBP: 1ffff1100b6b9e1b R08: ffffffff8950bf6e R09: ffff88805b5cff58 R10: ffff88805b5cf185 R11: 0000000000058071 R12: 00007f0616b54c78 R13: ffff88805b5c8000 R14: ffff88805b5cff58 R15: 0000000000000001 __save_stack_trace+0x6b/0xd0 arch/x86/kernel/stacktrace.c:44 save_stack+0x32/0xa0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15b/0x7c0 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] kzalloc include/linux/slab.h:661 [inline] ext4_find_extent+0x71a/0x990 fs/ext4/extents.c:900 ext4_ext_map_blocks+0x16f/0x4b80 fs/ext4/extents.c:4311 ext4_map_blocks+0xc6b/0x1610 fs/ext4/inode.c:567 ext4_getblk+0x98/0x3f0 fs/ext4/inode.c:980 ext4_bread+0x6c/0x1a0 fs/ext4/inode.c:1030 ext4_append+0x143/0x350 fs/ext4/namei.c:65 ext4_init_new_dir fs/ext4/namei.c:2628 [inline] ext4_mkdir+0x4c9/0xb60 fs/ext4/namei.c:2675 vfs_mkdir+0x3af/0x620 fs/namei.c:3849 ovl_do_mkdir fs/overlayfs/overlayfs.h:109 [inline] ovl_create_real+0x1e9/0x240 fs/overlayfs/dir.c:103 ovl_workdir_create+0x2d4/0x470 fs/overlayfs/super.c:508 ovl_fill_super+0x1009/0x265d fs/overlayfs/super.c:988 mount_nodev+0x4c/0xf0 fs/super.c:1180 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x3c0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0x3c9/0x24f0 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c849 RSP: 002b:00007f0616b54c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f0616b556d4 RCX: 000000000045c849 RDX: 00000000200000c0 RSI: 0000000020000000 RDI: 000000000040000a RBP: 000000000076bf00 R08: 0000000020000100 R09: 0000000000000000 R10: 000000000000000c R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000755 R14: 00000000004ca11e R15: 000000000076bf0c INFO: rcu_sched detected stalls on CPUs/tasks: 1-...: (10501 ticks this GP) idle=d02/140000000000001/0 softirq=25373/25373 fqs=0 (detected by 0, t=10574 jiffies, g=4140, c=4139, q=2) rcu_sched kthread starved for 10574 jiffies! g4140 c4139 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=1 rcu_sched R running task 29984 9 2 0x80000000 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x43c/0xe40 kernel/time/timer.c:1746 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404