rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=d254/1/0x4000000000000000 softirq=26171/26185 fqs=4321 rcu: hardirqs softirqs csw/system rcu: number: 1249345 0 0 rcu: cputime: 17372 33203 44 ==> 50580(ms) rcu: (t=10500 jiffies g=31069 q=2162 ncpus=2) CPU: 0 PID: 9262 Comm: syz.2.1112 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x10/0x60 kernel/kcov.c:216 Code: 89 fb e8 13 00 00 00 48 8b 3d cc 02 04 0d 48 89 de 5b e9 b3 a3 57 00 cc cc cc f3 0f 1e fa 48 8b 04 24 65 48 8b 0d e0 d2 7c 7e <65> 8b 15 e1 d2 7c 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 RSP: 0018:ffffc90000007480 EFLAGS: 00000246 RAX: ffffffff81328ef0 RBX: ffffc90000007540 RCX: ffff8880767e1e00 RDX: 0000000000000100 RSI: ffffc90000007540 RDI: ffffffff81758be0 RBP: ffffc90000007510 R08: ffffc900000078b0 R09: 0000000000000000 R10: ffffc900000075d0 R11: fffffbfff22378a1 R12: ffff8880767e1e00 R13: 00000000000000f0 R14: ffffffff81758be0 R15: 0000000000000000 FS: 00007fe0f59f66c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2de05ff8 CR3: 0000000063453000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: get_stack_pointer arch/x86/include/asm/stacktrace.h:96 [inline] unwind_start arch/x86/include/asm/unwind.h:62 [inline] arch_stack_walk+0x80/0x190 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6a/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] kmem_cache_alloc_node+0x1af/0x310 mm/slub.c:3540 __alloc_skb+0x103/0x2c0 net/core/skbuff.c:643 __netdev_alloc_skb+0x10c/0x500 net/core/skbuff.c:717 netdev_alloc_skb include/linux/skbuff.h:3304 [inline] dev_alloc_skb include/linux/skbuff.h:3317 [inline] hsr_init_skb+0xec/0x5a0 net/hsr/hsr_device.c:266 send_hsr_supervision_frame+0x145/0xb90 net/hsr/hsr_device.c:309 hsr_announce+0x198/0x350 net/hsr/hsr_device.c:402 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x570/0x810 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x27d/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:finish_task_switch+0x267/0x8f0 kernel/sched/core.c:5255 Code: 26 09 85 c0 0f 84 30 01 00 00 48 85 db 0f 85 4f 01 00 00 0f 1f 44 00 00 4c 89 e7 e8 93 3b 30 09 e8 7e 0b 30 00 fb 4c 8b 65 b8 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 RSP: 0018:ffffc900031f7220 EFLAGS: 00000282 RAX: d625d06ac67e7100 RBX: 0000000000000000 RCX: d625d06ac67e7100 RDX: dffffc0000000000 RSI: ffffffff8acacb60 RDI: ffffffff8b1c7be0 RBP: ffffc900031f7270 R08: ffffffff911bc527 R09: 1ffffffff22378a4 R10: dffffc0000000000 R11: fffffbfff22378a5 R12: ffff8880767e1e00 R13: 1ffff110171c79a9 R14: dffffc0000000000 R15: ffff8880b8e3cd48 context_switch kernel/sched/core.c:5384 [inline] __schedule+0x15b6/0x4660 kernel/sched/core.c:6700 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 __slab_alloc mm/slub.c:3341 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] kmem_cache_alloc_node+0x14b/0x310 mm/slub.c:3540 kmalloc_reserve+0x95/0x240 net/core/skbuff.c:562 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653 alloc_skb include/linux/skbuff.h:1316 [inline] alloc_uevent_skb+0x7d/0x230 lib/kobject_uevent.c:290 uevent_net_broadcast_untagged lib/kobject_uevent.c:326 [inline] kobject_uevent_net_broadcast+0x2e6/0x530 lib/kobject_uevent.c:409 kobject_uevent_env+0x559/0x890 lib/kobject_uevent.c:608 nfs_net_init+0x207/0x2b0 fs/nfs/inode.c:2449 ops_init+0x391/0x640 net/core/net_namespace.c:139 setup_net+0x3b6/0xa20 net/core/net_namespace.c:343 copy_net_ns+0x35e/0x5d0 net/core/net_namespace.c:520 create_new_namespaces+0x3ce/0x700 kernel/nsproxy.c:110 copy_namespaces+0x42a/0x4a0 kernel/nsproxy.c:179 copy_process+0x174a/0x3df0 kernel/fork.c:2511 kernel_clone+0x24b/0x8a0 kernel/fork.c:2917 __do_sys_clone kernel/fork.c:3060 [inline] __se_sys_clone kernel/fork.c:3044 [inline] __x64_sys_clone+0x1b7/0x230 kernel/fork.c:3044 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fe0f779ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe0f59f5fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007fe0f7a15fa0 RCX: 00007fe0f779ce59 RDX: 0000200000000240 RSI: 00002000000001c0 RDI: 0000000040188000 RBP: 00007fe0f7832e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000140 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fe0f7a16038 R14: 00007fe0f7a15fa0 R15: 00007ffea2d95b78