rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=508701, q=36) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295285870-4295275368), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g508701 f0x2 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:28032 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4681 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5938 schedule+0xd3/0x270 kernel/sched/core.c:6017 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline] rcu_gp_kthread+0xd34/0x1980 kernel/rcu/tree.c:2169 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: 19476 Comm: syz-executor.4 Not tainted 5.14.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:unwind_next_frame+0xa/0x1ce0 arch/x86/kernel/unwind_orc.c:418 Code: e8 db c4 88 00 48 8b 04 24 eb bd 48 89 0c 24 e8 4c c4 88 00 48 8b 0c 24 e9 72 ff ff ff 0f 1f 00 48 b8 00 00 00 00 00 fc ff df <41> 57 41 56 49 89 fe 41 55 41 54 55 53 48 81 ec a0 00 00 00 48 c7 RSP: 0018:ffffc90000007708 EFLAGS: 00000202 RAX: dffffc0000000000 RBX: ffffffff816417f0 RCX: 0000000000000000 RDX: 1ffff92000000f11 RSI: ffffffff81650843 RDI: ffffc90000007710 RBP: ffffc90000007798 R08: ffffffff8deaa6da R09: 0000000000000001 R10: fffff52000000eed R11: 0000000000086088 R12: ffffc900000077c8 R13: 0000000000000000 R14: ffff88801f2dd4c0 R15: 0000000000000a20 FS: 00007ff18154d700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000005131f0 CR3: 0000000078256000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 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_slab_alloc+0x84/0xa0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc_node mm/slub.c:2956 [inline] slab_alloc mm/slub.c:2964 [inline] kmem_cache_alloc+0x285/0x4a0 mm/slub.c:2969 skb_clone+0x170/0x3c0 net/core/skbuff.c:1520 hsr_create_tagged_frame+0x173/0xb60 net/hsr/hsr_forward.c:251 hsr_forward_do net/hsr/hsr_forward.c:417 [inline] hsr_forward_skb+0x84c/0x1620 net/hsr/hsr_forward.c:578 send_hsr_supervision_frame+0x60b/0x8d0 net/hsr/hsr_device.c:324 hsr_announce+0x109/0x330 net/hsr/hsr_device.c:382 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:debug_spin_lock_after kernel/locking/spinlock_debug.c:92 [inline] RIP: 0010:do_raw_spin_lock+0x17b/0x2b0 kernel/locking/spinlock_debug.c:115 Code: 0f b6 14 02 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 d9 00 00 00 4c 89 ea 44 89 75 08 48 b8 00 00 00 00 00 fc ff df <48> c1 ea 03 65 4c 8b 24 25 00 f0 01 00 80 3c 02 00 0f 85 e4 00 00 RSP: 0018:ffffc90002e3f9c8 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 1ffff920005c7f3a RCX: ffffffff815b9610 RDX: ffff88801a5677c8 RSI: 0000000000000004 RDI: ffffc90002e3f9f0 RBP: ffff88801a5677b8 R08: 0000000000000001 R09: 0000000000000003 R10: fffff520005c7f3e R11: 0000000000000000 R12: ffff88801a5677c0 R13: ffff88801a5677c8 R14: 0000000000000000 R15: 0000000000000000 spin_lock include/linux/spinlock.h:354 [inline] __find_get_block_slow fs/buffer.c:206 [inline] __find_get_block fs/buffer.c:1308 [inline] __find_get_block+0x4df/0xdb0 fs/buffer.c:1302 sb_find_get_block include/linux/buffer_head.h:340 [inline] recently_deleted fs/ext4/ialloc.c:687 [inline] find_inode_bit+0x230/0x580 fs/ext4/ialloc.c:729 __ext4_new_inode+0xc4d/0x5c40 fs/ext4/ialloc.c:1064 ext4_mkdir+0x33a/0xb20 fs/ext4/namei.c:2921 vfs_mkdir+0x52e/0x760 fs/namei.c:3823 do_mkdirat+0x284/0x310 fs/namei.c:3848 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: 0033:0x4665e9 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:00007ff18154d188 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffe8aaabc8f R14: 00007ff18154d300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: e8 db c4 88 00 callq 0x88c4e0 5: 48 8b 04 24 mov (%rsp),%rax 9: eb bd jmp 0xffffffc8 b: 48 89 0c 24 mov %rcx,(%rsp) f: e8 4c c4 88 00 callq 0x88c460 14: 48 8b 0c 24 mov (%rsp),%rcx 18: e9 72 ff ff ff jmpq 0xffffff8f 1d: 0f 1f 00 nopl (%rax) 20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 27: fc ff df * 2a: 41 57 push %r15 <-- trapping instruction 2c: 41 56 push %r14 2e: 49 89 fe mov %rdi,%r14 31: 41 55 push %r13 33: 41 54 push %r12 35: 55 push %rbp 36: 53 push %rbx 37: 48 81 ec a0 00 00 00 sub $0xa0,%rsp 3e: 48 rex.W 3f: c7 .byte 0xc7