rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10503 jiffies, g=101461, q=115 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4295034381-4295023878), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10503 jiffies! g101461 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27184 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2034 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2236 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 10330 Comm: kworker/0:11 Not tainted 6.11.0-rc2-syzkaller-00011-geb5e56d14912 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:write_comp_data+0x11/0x90 kernel/kcov.c:236 Code: cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 49 89 d2 49 89 f8 49 89 f1 65 48 8b 15 4f 64 79 7e <65> 8b 05 50 64 79 7e a9 00 01 ff 00 74 0f f6 c4 01 74 59 8b 82 1c RSP: 0018:ffffc90000007e28 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 19c61765fae90172 RCX: ffffffff81778fc6 RDX: ffff88807a8abc00 RSI: 19c61765fae90172 RDI: 0000000000000006 RBP: 17efa6eed8000000 R08: 0000000000000006 R09: 19c61765fae90172 R10: 17efa6eed8000000 R11: ffffffff8b4f50a0 R12: ffff8880b922cac0 R13: ffff88802ee2a340 R14: ffff8880b922c9c0 R15: ffffffff8921d8c0 FS: 0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbe68b5f270 CR3: 00000000235d4000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __hrtimer_run_queues+0x416/0xcc0 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1815 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x10f/0x450 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline] RIP: 0010:unwind_next_frame+0x1b94/0x23a0 arch/x86/kernel/unwind_orc.c:648 Code: c2 0f 9e c1 84 d2 0f 95 c0 84 c1 0f 85 0a 08 00 00 4d 0f bf 64 24 02 ba 08 00 00 00 48 89 df 4d 01 ec 4c 89 e6 e8 ec e1 ff ff <31> ff 41 89 c5 89 c6 e8 60 7d 4d 00 48 8d 4b 34 45 84 ed 0f 84 3e RSP: 0018:ffffc90003b7f6e8 EFLAGS: 00000282 RAX: 0000000000000001 RBX: ffffc90003b7f768 RCX: ffffffff813cdd16 RDX: ffff88807a8abc00 RSI: ffffffff813cdd79 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffc90003b7fec0 R13: ffffc90003b7fef0 R14: 0000000000000001 R15: 0000000000000001 arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3988 [inline] slab_alloc_node mm/slub.c:4037 [inline] kmem_cache_alloc_node_noprof+0x153/0x310 mm/slub.c:4080 __alloc_skb+0x2b1/0x380 net/core/skbuff.c:664 alloc_skb include/linux/skbuff.h:1320 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x2a4/0xc80 drivers/net/netdevsim/dev.c:850 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244