rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7619/1:b..l (detected by 1, t=10502 jiffies, g=216589, q=2765 ncpus=2) task:syz.0.11352 state:R running task stack:25712 pid:7619 ppid:362 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_release+0x5ab/0x920 kernel/locking/lockdep.c:5686 Code: 00 00 00 f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 2f 04 f8 75 70 f7 44 24 50 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 2f 00 00 00 00 43 c7 44 2f 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc9000579f3c0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: da2e616334457c0f RCX: 6d4b560aae181d00 RDX: 0000000000000001 RSI: ffffffff8a8c22a0 RDI: ffffffff8adf13a0 RBP: ffffc9000579f4e0 R08: ffffffff8e1ff42f R09: 1ffffffff1c3fe85 R10: dffffc0000000000 R11: fffffbfff1c3fe86 R12: ffff88802e334688 R13: dffffc0000000000 R14: ffff88802e334650 R15: 1ffff92000af3e84 rcu_lock_release include/linux/rcupdate.h:355 [inline] rcu_read_unlock include/linux/rcupdate.h:824 [inline] is_bpf_text_address+0x28b/0x2a0 kernel/bpf/core.c:737 kernel_text_address+0x9c/0xd0 kernel/extable.c:125 __kernel_text_address+0x9/0x30 kernel/extable.c:79 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc+0x123/0x2f0 mm/slub.c:3383 skb_clone+0x1e7/0x370 net/core/skbuff.c:1660 ____bpf_clone_redirect net/core/filter.c:2458 [inline] bpf_clone_redirect+0x163/0x4a0 net/core/filter.c:2436 bpf_prog_1ae46246a44230f4+0x19/0x1d bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline] __bpf_prog_run include/linux/filter.h:596 [inline] bpf_prog_run include/linux/filter.h:614 [inline] bpf_test_run+0x4c1/0x830 net/bpf/test_run.c:402 bpf_prog_test_run_skb+0xaa6/0x12a0 net/bpf/test_run.c:1191 bpf_prog_test_run+0x31e/0x390 kernel/bpf/syscall.c:3695 __sys_bpf+0x62b/0x780 kernel/bpf/syscall.c:5049 __do_sys_bpf kernel/bpf/syscall.c:5135 [inline] __se_sys_bpf kernel/bpf/syscall.c:5133 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5133 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3c3c39cdd9 RSP: 002b:00007f3c3d17a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f3c3c615fa0 RCX: 00007f3c3c39cdd9 RDX: 0000000000000050 RSI: 00002000000003c0 RDI: 000000000000000a RBP: 00007f3c3c432d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3c3c616038 R14: 00007f3c3c615fa0 R15: 00007ffcfc3a69c8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10419 jiffies! g216589 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=158648 rcu: rcu_preempt kthread starved for 10420 jiffies! g216589 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26864 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 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: 7617 Comm: syz.0.11352 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:193 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x32/0x60 kernel/kcov.c:216 Code: e4 f9 7f 7e 65 8b 15 e5 f9 7f 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 <83> fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc RSP: 0018:ffffc9000578f8d8 EFLAGS: 00000046 RAX: ffffffff818c23f3 RBX: 0000000000000001 RCX: ffff88802fcf9dc0 RDX: 0000000000000000 RSI: ffffffff8adf1380 RDI: ffffffff8adf1340 RBP: ffffc9000578f9d8 R08: dffffc0000000000 R09: 1ffffffff215f248 R10: dffffc0000000000 R11: fffffbfff215f249 R12: 0000000000120000 R13: 1ffff92000af1f28 R14: ffff888030a9aba8 R15: 0000000000000000 FS: 0000555576fd0500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f761d957ef0 CR3: 00000000a2d0f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff1 DR7: 0000000000000600 Call Trace: rcu_read_unlock include/linux/rcupdate.h:820 [inline] trace_call_bpf+0x4e3/0x6b0 kernel/trace/bpf_trace.c:137 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10027 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728 RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 d2 33 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc9000578fc00 EFLAGS: 00000206 RAX: ef8c1fb23681c700 RBX: 1ffff92000af1f88 RCX: ef8c1fb23681c700 RDX: dffffc0000000000 RSI: ffffffff8a8c1120 RDI: ffffffff8adf13a0 RBP: ffffc9000578fcf8 R08: ffffffff90af924f R09: 1ffffffff215f249 R10: dffffc0000000000 R11: fffffbfff215f24a R12: 0000000000000246 R13: dffffc0000000000 R14: 0000000000000000 R15: ffffffff8cb32c18 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock+0x85/0xa0 include/linux/rcupdate.h:823 dput+0xe2/0x1d0 fs/dcache.c:911 __fput+0x5e0/0x920 fs/file_table.c:328 task_work_run+0x1d0/0x260 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3c3c39cdd9 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:00007ffcfc3a6b28 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f3c3c617da0 RCX: 00007f3c3c39cdd9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f3c3c617da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007f3c3c617cb0 R11: 0000000000000246 R12: 00000000001e7087 R13: 00007f3c3c615fac R14: 00000000001e6d8d R15: 00007ffcfc3a6c30