rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=413c/1/0x4000000000000000 softirq=25824/25824 fqs=0 rcu: (detected by 0, t=10502 jiffies, g=23145, q=372 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6261 Comm: udevd Not tainted 6.14.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 7e 60 e8 a3 ff ff ff 31 c0 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 65 48 8b 15 44 f9 49 7e 65 8b 05 45 f9 49 7e a9 00 01 RSP: 0018:ffffc90000a18d78 EFLAGS: 00000082 RAX: ffff88802848a440 RBX: 0000000000000000 RCX: 1ffff110050915e3 RDX: ffff88802848a440 RSI: ffffffff81a70e26 RDI: ffff888077587340 RBP: 000000000003d94c R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888077587340 R13: ffff8880b872c780 R14: ffff888077587340 R15: ffffffff896a7a20 FS: 00007f64ec897280(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c303a79 CR3: 0000000031acc000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000097 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: advance_sched+0x1a/0xc60 net/sched/sch_taprio.c:914 __run_hrtimer kernel/time/hrtimer.c:1801 [inline] __hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:find_stack lib/stackdepot.c:552 [inline] RIP: 0010:stack_depot_save_flags+0x135/0x9c0 lib/stackdepot.c:618 Code: 29 df 31 f8 c1 cf 08 29 f8 89 c3 41 89 d9 44 23 0d d0 45 c3 15 49 c1 e1 04 4c 03 0d cd 45 c3 15 65 ff 05 26 0f 10 7b 49 8b 09 <4c> 39 c9 75 11 e9 91 00 00 00 48 8b 09 49 39 c9 0f 84 d8 01 00 00 RSP: 0018:ffffc9000c1af568 EFLAGS: 00000282 RAX: 00000000a57e4c6c RBX: 00000000a57e4c6c RCX: ffff888033b89e80 RDX: 00000000fb53c4e9 RSI: 000000006a7be26e RDI: 000000004f6b5c95 RBP: 0000000000000001 R08: 0000000000000000 R09: ffff88823bc4c6c0 R10: ffffffff90625617 R11: 0000000000000000 R12: 0000000000000cc0 R13: ffffc9000c1af5c8 R14: 000000000000000c R15: 000000000000000c kasan_save_stack+0x42/0x60 mm/kasan/common.c:48 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_noprof+0x226/0x3d0 mm/slub.c:4171 skb_clone+0x190/0x3f0 net/core/skbuff.c:1994 do_one_broadcast net/netlink/af_netlink.c:1453 [inline] netlink_broadcast_filtered+0xb11/0xef0 net/netlink/af_netlink.c:1531 netlink_broadcast net/netlink/af_netlink.c:1555 [inline] netlink_sendmsg+0xa06/0xd70 net/netlink/af_netlink.c:1890 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:733 [inline] ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2627 __sys_sendmsg+0x16e/0x220 net/socket.c:2659 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f64ec524a4b Code: ff 89 ef 48 89 04 24 e8 22 56 f9 ff 48 8b 04 24 48 83 c4 20 5d c3 c3 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 6d 48 8b 15 ae c3 0c 00 f7 d8 64 89 02 48 83 RSP: 002b:00007fffd716f7e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000560543a70ce0 RCX: 00007f64ec524a4b RDX: 0000000000000000 RSI: 00007fffd716f7f8 RDI: 000000000000000c RBP: 0000000000000000 R08: 0000000000000001 R09: 3d361ada87b6a5e3 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000088 R14: 0000000000000000 R15: 00005605439db2c0 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g23145 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=12925 rcu: rcu_preempt kthread starved for 10502 jiffies! g23145 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:27552 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244