rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (1 GPs behind) idle=4454/1/0x4000000000000000 softirq=107986/107987 fqs=4469 rcu: hardirqs softirqs csw/system rcu: number: 1370724 0 0 rcu: cputime: 19018 33451 68 ==> 52470(ms) rcu: (t=10500 jiffies g=143825 q=1281 ncpus=2) CPU: 1 PID: 6587 Comm: syz.1.5968 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:stack_trace_save+0x0/0x100 kernel/stacktrace.c:114 Code: c4 49 89 cc 77 89 44 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 0b 45 31 ed eb e7 66 2e 0f 1f 84 00 00 00 00 00 90 0f 1e fa 55 48 89 e5 41 56 53 48 83 e4 e0 48 81 ec 80 00 00 00 RSP: 0018:ffffc900001f0778 EFLAGS: 00000246 RAX: ffffc900001f0780 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffffc900001f0780 RBP: ffffc900001f09b0 R08: dffffc0000000000 R09: 0000000000000000 R10: ffffc900001f0780 R11: fffffbfff22388c6 R12: 0000000000000000 R13: ffffc900001f0a60 R14: ffff88805cd1e808 R15: ffffc900001f0780 FS: 00007fd56b1456c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000000 CR3: 000000002f84c000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: 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:949 [inline] skb_free_head net/core/skbuff.c:961 [inline] skb_release_data+0x634/0x800 net/core/skbuff.c:991 skb_release_all net/core/skbuff.c:1057 [inline] __kfree_skb net/core/skbuff.c:1071 [inline] kfree_skb_reason+0x10e/0x170 net/core/skbuff.c:1107 inet_frag_rbtree_purge net/ipv4/inet_fragment.c:282 [inline] inet_frag_destroy+0x179/0x290 net/ipv4/inet_fragment.c:306 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:generic_exec_single+0x481/0x4f0 kernel/smp.c:418 Code: 75 11 e8 42 05 0b 00 48 85 db 75 16 e8 38 05 0b 00 eb 15 e8 31 05 0b 00 e8 bc 08 0a 09 48 85 db 74 ea e8 22 05 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 43 c7 44 2c 08 RSP: 0018:ffffc9000bbf7a00 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000080000 RDX: ffffc9000e8a0000 RSI: 0000000000001b72 RDI: 0000000000001b73 RBP: ffffc9000bbf7ad0 R08: ffffffff911c45ff R09: 1ffffffff22388bf R10: dffffc0000000000 R11: fffffbfff22388c0 R12: 1ffff9200177ef44 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff9200177ef65 smp_call_function_single+0x36d/0x5a0 kernel/smp.c:647 task_function_call kernel/events/core.c:120 [inline] perf_install_in_context+0x5be/0x920 kernel/events/core.c:2959 __do_sys_perf_event_open kernel/events/core.c:12957 [inline] __se_sys_perf_event_open+0x1836/0x1c50 kernel/events/core.c:12609 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fd56a19c819 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:00007fd56b145028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007fd56a415fa0 RCX: 00007fd56a19c819 RDX: ffffff7fffffffff RSI: 0000000000000000 RDI: 0000200000000480 RBP: 00007fd56a232c91 R08: 0000000000000008 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd56a416038 R14: 00007fd56a415fa0 R15: 00007ffd7e5de518