rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (10499 ticks this GP) idle=9904/1/0x4000000000000000 softirq=31361/31364 fqs=3888 rcu: hardirqs softirqs csw/system rcu: number: 1654513 4 0 rcu: cputime: 17664 32954 30 ==> 50620(ms) rcu: (t=10500 jiffies g=33977 q=591 ncpus=2) CPU: 1 PID: 10652 Comm: syz.2.1370 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:-1 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline] RIP: 0010:unwind_next_frame+0x4d9/0x2970 arch/x86/kernel/unwind_orc.c:494 Code: ef 4c 89 f6 e8 28 f1 4b 00 49 8d 47 04 4d 39 f5 4c 0f 46 e0 49 8d 47 fc 48 0f 47 d8 49 0f 46 ef 49 39 dc 77 28 e8 f7 ee 4b 00 <48> ba 00 00 00 00 00 fc ff df eb 97 44 89 f9 80 e1 07 80 c1 03 38 RSP: 0018:ffffc900001efd98 EFLAGS: 00000246 RAX: ffffffff813b3c99 RBX: ffffffff8f064bbc RCX: ffff888019351e00 RDX: 0000000000000100 RSI: ffffffff8a909ccc RDI: ffffffff8a909c18 RBP: ffffffff8f064bb8 R08: ffffc900001eff30 R09: 0000000000000019 R10: 0000000000000004 R11: 0000000000000100 R12: ffffffff8f064bbc R13: ffffffff8a909c18 R14: ffffffff8a909ccc R15: ffffffff8f064bb8 FS: 00007f237217d6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000000 CR3: 00000000467b1000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 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_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1e0 mm/slub.c:3843 skb_kfree_head net/core/skbuff.c:946 [inline] skb_free_head net/core/skbuff.c:958 [inline] skb_release_data+0x5dc/0x7b0 net/core/skbuff.c:988 skb_release_all net/core/skbuff.c:1054 [inline] __kfree_skb net/core/skbuff.c:1068 [inline] kfree_skb_reason+0x10e/0x170 net/core/skbuff.c:1104 kfree_skb include/linux/skbuff.h:1264 [inline] hsr_forward_skb+0x885/0x2140 net/hsr/hsr_forward.c:-1 hsr_dev_xmit+0x1e7/0x350 net/hsr/hsr_device.c:238 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3644 [inline] dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3660 __dev_queue_xmit+0x19a3/0x3660 net/core/dev.c:4454 dev_queue_xmit include/linux/netdevice.h:3113 [inline] br_send_bpdu_finish net/bridge/br_stp_bpdu.c:32 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] br_send_bpdu+0x479/0x920 net/bridge/br_stp_bpdu.c:59 br_send_config_bpdu+0x473/0x740 net/bridge/br_stp_bpdu.c:120 br_transmit_config+0x3be/0x5d0 net/bridge/br_stp.c:241 br_hold_timer_expired+0x85/0x170 net/bridge/br_stp_timer.c:137 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x542/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 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+0x26a/0x8f0 kernel/sched/core.c:5255 Code: 0f 84 33 01 00 00 48 85 db 0f 85 52 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 e0 94 34 09 e8 1b 2f 30 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffc90003bd7878 EFLAGS: 00000286 RAX: b5f27f7f3e23d000 RBX: 0000000000000000 RCX: b5f27f7f3e23d000 RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: ffffffff8b1c9c20 RBP: ffffc90003bd78d0 R08: ffffffff8e8b666f R09: 1ffffffff1d16ccd R10: dffffc0000000000 R11: fffffbfff1d16cce R12: ffff888019351e00 R13: dffffc0000000000 R14: ffff8880285e3c00 R15: ffff8880b8f3cb48 context_switch kernel/sched/core.c:5384 [inline] __schedule+0x155b/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 futex_wait_queue+0x138/0x1b0 kernel/futex/waitwake.c:355 futex_wait+0x1ec/0x5e0 kernel/futex/waitwake.c:656 do_futex+0x2ff/0x3e0 kernel/futex/syscalls.c:134 __do_sys_futex kernel/futex/syscalls.c:211 [inline] __se_sys_futex+0x3a9/0x440 kernel/futex/syscalls.c:192 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: 0033:0x7f237139ce59 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:00007f237217d0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f2371615fa8 RCX: 00007f237139ce59 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2371615fa8 RBP: 00007f2371615fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2371616038 R14: 00007fff52f7eaa0 R15: 00007fff52f7eb88