rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10500 ticks this GP) idle=9a44/1/0x4000000000000000 softirq=65629/98348 fqs=5065 rcu: hardirqs softirqs csw/system rcu: number: 1710977 21400 0 rcu: cputime: 45635 6793 78 ==> 52490(ms) rcu: (t=10500 jiffies g=71505 q=2631 ncpus=2) CPU: 0 PID: 14823 Comm: syz.4.2749 Not tainted 6.6.102-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_switch+0xb0/0x120 kernel/kcov.c:350 Code: c8 74 77 4e 8b 54 ce 10 65 44 8b 1d 92 29 7e 7e 41 81 e3 00 01 ff 00 74 13 41 81 fb 00 01 00 00 75 d9 41 83 b8 1c 16 00 00 00 <74> cf 45 8b 98 f8 15 00 00 41 83 fb 03 75 c2 4d 8b 98 00 16 00 00 RSP: 0018:ffffc90000007448 EFLAGS: 00000246 RAX: 0000000000000020 RBX: 0000000000000004 RCX: 0000000000000005 RDX: ffffffff818755b5 RSI: ffffffff8cd79180 RDI: 0000000000000004 RBP: 0000000000000424 R08: ffff888028df8000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000100 R12: dffffc0000000000 R13: f800000000000000 R14: ffff8880182420c4 R15: 0000000000eb0404 FS: 00007f1bdfa426c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000003b000 CR3: 0000000068bad000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: rb_event_length+0x45/0x3f0 kernel/trace/ring_buffer.c:198 check_buffer+0x542/0x950 kernel/trace/ring_buffer.c:3491 __rb_reserve_next+0x511/0xd50 kernel/trace/ring_buffer.c:3624 rb_reserve_next_event kernel/trace/ring_buffer.c:3759 [inline] ring_buffer_lock_reserve+0xae1/0xed0 kernel/trace/ring_buffer.c:3818 __trace_buffer_lock_reserve kernel/trace/trace.c:992 [inline] trace_event_buffer_lock_reserve+0x1d0/0x6e0 kernel/trace/trace.c:2902 trace_event_buffer_reserve+0x29b/0x3c0 kernel/trace/trace_events.c:661 do_trace_event_raw_event_bpf_trace_printk kernel/trace/bpf_trace.h:11 [inline] trace_event_raw_event_bpf_trace_printk+0x101/0x210 kernel/trace/bpf_trace.h:11 trace_bpf_trace_printk+0x142/0x1a0 kernel/trace/bpf_trace.h:11 ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] bpf_trace_printk+0x11f/0x190 kernel/trace/bpf_trace.c:371 bpf_prog_0605f9f479290f07+0x37/0x3b bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline] __bpf_prog_run include/linux/filter.h:605 [inline] bpf_prog_run include/linux/filter.h:619 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run1+0x30a/0x3b0 kernel/trace/bpf_trace.c:2360 __bpf_trace_rcu_utilization+0xa2/0xe0 include/trace/events/rcu.h:27 trace_rcu_utilization+0x179/0x1a0 include/trace/events/rcu.h:27 rcu_core+0x1341/0x1720 kernel/rcu/tree.c:2475 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+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0xa1/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:723 RIP: 0010:preempt_schedule_irq+0xb0/0x140 kernel/sched/core.c:7009 Code: 44 24 20 f6 44 24 21 02 74 0b 0f 0b 48 f7 03 08 00 00 00 74 63 bf 01 00 00 00 e8 4b da e5 f6 e8 46 5f 16 f7 fb bf 01 00 00 00 db b5 ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24 RSP: 0018:ffffc9000495f180 EFLAGS: 00000282 RAX: e2b4dc5a1b527000 RBX: 0000000000000000 RCX: e2b4dc5a1b527000 RDX: dffffc0000000000 RSI: ffffffff8aaab9c0 RDI: 0000000000000001 RBP: ffffc9000495f220 R08: ffffffff90da35af R09: 1ffffffff21b46b5 R10: dffffc0000000000 R11: fffffbfff21b46b6 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff9200092be30 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:memset_orig+0x36/0xac arch/x86/lib/memset_64.S:68 Code: b8 01 01 01 01 01 01 01 01 48 0f af c1 41 89 f9 41 83 e1 07 75 6c 48 89 d1 48 c1 e9 06 74 35 0f 1f 44 00 00 48 ff c9 48 89 07 <48> 89 47 08 48 89 47 10 48 89 47 18 48 89 47 20 48 89 47 28 48 89 RSP: 0018:ffffc9000495f2e8 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffff888047f00000 RCX: 0000000000000007 RDX: 0000000000000200 RSI: 0000000000000000 RDI: ffffed1008fe0000 RBP: ffffea00011fc000 R08: ffffea00011fc037 R09: 0000000000000000 R10: ffffed1008fe0000 R11: fffff9400023f807 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000001000 R15: dffffc0000000000 kasan_poison mm/kasan/shadow.c:150 [inline] kasan_unpoison+0x67/0x90 mm/kasan/shadow.c:190 __kasan_unpoison_pages+0x24/0x30 mm/kasan/common.c:110 kasan_unpoison_pages include/linux/kasan.h:121 [inline] post_alloc_hook+0xbc/0x210 mm/page_alloc.c:1538 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 __folio_alloc+0x10/0x20 mm/page_alloc.c:4489 vma_alloc_folio+0x47a/0x8f0 mm/mempolicy.c:2242 shmem_alloc_folio+0x179/0x230 mm/shmem.c:1680 shmem_alloc_and_acct_folio+0x189/0x630 mm/shmem.c:1705 shmem_get_folio_gfp+0xcde/0x2ac0 mm/shmem.c:2042 shmem_get_folio mm/shmem.c:2165 [inline] shmem_write_begin+0xf2/0x420 mm/shmem.c:2707 generic_perform_write+0x2fb/0x5b0 mm/filemap.c:4016 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:2884 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x43b/0x940 fs/read_write.c:584 ksys_write+0x147/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1bdeb8ebe9 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1bdfa42038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f1bdedb5fa0 RCX: 00007f1bdeb8ebe9 RDX: 00000000002a979d RSI: 0000200000000000 RDI: 0000000000000006 RBP: 00007f1bdec11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1bdedb6038 R14: 00007f1bdedb5fa0 R15: 00007ffcd4c992e8