rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2903/1:b..l (detected by 0, t=10502 jiffies, g=232013, q=538 ncpus=2) task:syz.4.8248 state:R running task stack:25176 pid:2903 ppid:26739 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6875 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:should_resched arch/x86/include/asm/preempt.h:103 [inline] RIP: 0010:__local_bh_enable_ip+0x13e/0x1c0 kernel/softirq.c:428 Code: 8a e8 b6 f2 e0 08 65 66 8b 05 2e 67 b4 7e 66 85 c0 75 54 bf 01 00 00 00 e8 6f 82 09 00 e8 ca 57 39 00 fb 65 8b 05 da 33 b3 7e <85> c0 75 05 e8 e9 47 b1 ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00 RSP: 0018:ffffc90004c077e0 EFLAGS: 00000282 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 40e75069699d0200 RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adf5de0 RBP: ffffc90004c07870 R08: ffff8880b8f3580b R09: 1ffff110171e6b01 R10: dffffc0000000000 R11: ffffed10171e6b02 R12: ffffffff886ef485 R13: ffff888055c7fc80 R14: dffffc0000000000 R15: 1ffff92000980efc local_bh_enable include/linux/bottom_half.h:33 [inline] xdp_test_run_batch net/bpf/test_run.c:340 [inline] bpf_test_run_xdp_live+0x1835/0x1a90 net/bpf/test_run.c:362 bpf_prog_test_run_xdp+0x757/0xf80 net/bpf/test_run.c:1457 bpf_prog_test_run+0x31c/0x390 kernel/bpf/syscall.c:3695 __sys_bpf+0x62b/0x780 kernel/bpf/syscall.c:5050 __do_sys_bpf kernel/bpf/syscall.c:5136 [inline] __se_sys_bpf kernel/bpf/syscall.c:5134 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5134 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: 0033:0x7fb26399e0d9 RSP: 002b:00007fb264819028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fb263c25fa0 RCX: 00007fb26399e0d9 RDX: 0000000000000048 RSI: 0000200000000600 RDI: 000000000000000a RBP: 00007fb263a35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb263c26038 R14: 00007fb263c25fa0 R15: 00007ffd7b8e0fe8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g232013 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=165444 rcu: rcu_preempt kthread starved for 10500 jiffies! g232013 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 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:27472 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1350 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2907 Comm: syz.4.8248 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:__rcu_read_unlock+0x49/0xd0 kernel/rcu/tree_plugin.h:425 Code: 04 00 00 49 89 dc 49 c1 ec 03 43 0f b6 04 3c 84 c0 75 48 ff 0b 75 1d 4c 8d b7 40 04 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 5f 41 83 3e 00 75 20 43 0f b6 04 3c 84 c0 75 3a 8b 03 3d RSP: 0018:ffffc900001e0ad0 EFLAGS: 00000802 RAX: 0000000000000000 RBX: ffff8880271ac03c RCX: ffff8880271abc00 RDX: 0000000000000100 RSI: ffffffff8adf5dc0 RDI: ffff8880271abc00 RBP: ffffc900001e0bf8 R08: ffffffff8fa25048 R09: ffffffff8fa25058 R10: ffffffff8fa25050 R11: ffffffff8fa25043 R12: 1ffff11004e35807 R13: 1ffff9200003c16c R14: ffff8880271ac040 R15: dffffc0000000000 FS: 00007fb2647f86c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000002e55b000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000200000000300 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: rcu_read_unlock include/linux/rcupdate.h:823 [inline] trace_call_bpf+0x5bb/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:variable_ffs arch/x86/include/asm/bitops.h:319 [inline] RIP: 0010:handle_softirqs+0x1b7/0x910 kernel/softirq.c:584 Code: 89 7c 24 2c 0f b7 db 48 c7 c7 80 0d 8b 8a e8 60 ee e0 08 65 66 c7 05 d6 62 b4 7e 00 00 e8 81 53 39 00 fb 49 c7 c5 c0 a0 80 8c <89> 5c 24 34 b8 ff ff ff ff 0f bc 44 24 34 41 89 c6 41 ff c6 0f 84 RSP: 0018:ffffc900001e0e20 EFLAGS: 00000282 RAX: 33ee9378debdb100 RBX: 0000000000000200 RCX: 33ee9378debdb100 RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adf5de0 RBP: ffffc900001e0f30 R08: ffff8880b8f3580b R09: 1ffff110171e6b01 R10: dffffc0000000000 R11: ffffed10171e6b02 R12: dffffc0000000000 R13: ffffffff8c80a0c0 R14: ffff8880271abc00 R15: 000000000000000a __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:rcu_read_unlock_special+0x6e/0x510 kernel/rcu/tree_plugin.h:634 Code: 8c 48 c7 44 24 50 30 f2 6c 81 48 8d 5c 24 40 48 c1 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 a2 7c 95 7e 41 f7 c6 00 00 f0 00 74 40 48 c7 44 24 40 RSP: 0018:ffffc90005f0f440 EFLAGS: 00000a06 RAX: f2f2f2f8f1f1f1f1 RBX: 1ffff92000be1e90 RCX: 0000000000080000 RDX: ffffc9001c3b8000 RSI: 00000000000015dc RDI: ffff8880271abc00 RBP: ffffc90005f0f540 R08: ffff8880569312c3 R09: 1ffff1100ad26258 R10: dffffc0000000000 R11: ffffed100ad26259 R12: 1ffff11004e35807 R13: dffffc0000000000 R14: ffff8880271ac040 R15: dffffc0000000000 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] ip6_route_output_flags+0x211/0x330 net/ipv6/route.c:2690 ip6_route_output include/net/ip6_route.h:98 [inline] ip6_dst_lookup_tail+0x1a7/0x1600 net/ipv6/ip6_output.c:1131 ip6_dst_lookup_flow net/ipv6/ip6_output.c:1262 [inline] ip6_sk_dst_lookup_flow+0x715/0x9b0 net/ipv6/ip6_output.c:1300 ping_v6_sendmsg+0xb9c/0x1170 net/ipv6/ping.c:154 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5ed/0x9a0 net/socket.c:2519 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2573 __sys_sendmsg net/socket.c:2602 [inline] __do_sys_sendmsg net/socket.c:2611 [inline] __se_sys_sendmsg+0x1c3/0x2b0 net/socket.c:2609 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: 0033:0x7fb26399e0d9 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:00007fb2647f8028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fb263c26090 RCX: 00007fb26399e0d9 RDX: 0000000000000000 RSI: 0000200000000440 RDI: 000000000000000d RBP: 00007fb263a35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb263c26128 R14: 00007fb263c26090 R15: 00007ffd7b8e0fe8