rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (4 ticks this GP) idle=5864/1/0x4000000000000000 softirq=53680/53682 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7734/1:b..l rcu: (detected by 0, t=10505 jiffies, g=25773, q=202 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 2955 Comm: kworker/u8:6 Not tainted 6.15.0-syzkaller-08486-gf66bc387efbe #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:in_softirq_really kernel/kcov.c:171 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x1e/0x70 kernel/kcov.c:217 Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 34 24 65 48 8b 15 28 26 ef 11 65 8b 05 39 26 ef 11 a9 00 01 ff 00 74 1d c4 01 74 43 a9 00 00 0f 00 75 3c a9 00 00 f0 00 75 35 8b 82 3c RSP: 0018:ffffc90000a08e38 EFLAGS: 00000006 RAX: 0000000080010201 RBX: ffff8880b8527d40 RCX: ffffffff81a89bf3 RDX: ffff888031754880 RSI: ffffffff81a89ffb RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: ffffffff9ae29010 R12: ffff8880b8527c40 R13: 18518951cc6252ee R14: ffff88805e2e0340 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888124a71000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f15f9b72720 CR3: 000000006e386000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1727 [inline] __hrtimer_run_queues+0x85b/0xad0 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__netif_rx+0x0/0xb0 net/core/dev.c:5505 Code: e8 c5 f9 ff ff 89 c3 e8 fe b5 65 f8 89 d8 5b 5d c3 cc cc cc cc 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 53 48 89 fb e8 d2 b5 65 f8 48 c7 c0 44 a7 87 90 48 RSP: 0018:ffffc9000c27f838 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff888058439c80 RCX: ffffffff86893cb3 RDX: ffff888031754880 RSI: ffffffff8689428d RDI: ffff888058439c80 RBP: ffff88805af8e000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: ffff88805b45a000 R14: ffff888058439cf0 R15: 0000000000000000 veth_forward_skb drivers/net/veth.c:321 [inline] veth_xmit+0x8c5/0xe90 drivers/net/veth.c:375 __netdev_start_xmit include/linux/netdevice.h:5215 [inline] netdev_start_xmit include/linux/netdevice.h:5224 [inline] xmit_one net/core/dev.c:3830 [inline] dev_hard_start_xmit+0x94/0x740 net/core/dev.c:3846 __dev_queue_xmit+0x7eb/0x43e0 net/core/dev.c:4713 dev_queue_xmit include/linux/netdevice.h:3355 [inline] batadv_send_skb_packet+0x58e/0x780 net/batman-adv/send.c:108 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:392 [inline] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:420 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x734/0x920 net/batman-adv/bat_iv_ogm.c:1708 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:syz.9.240 state:R running task stack:26664 pid:7734 tgid:7730 ppid:6665 task_flags:0x400040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5392 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6781 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7104 irqentry_exit+0x36/0x90 kernel/entry/common.c:307 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5875 Code: 98 12 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 92 1d ef 0e 0f 82 74 02 00 00 8b 35 7a 4f ef 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 29 98 12 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0000:ffffc9000c0ff258 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c4780 RCX: 00000000a22ac22b RDX: 0000000000000000 RSI: ffffffff8dbe196c RDI: ffffffff8bf53000 RBP: 0000000000000002 R08: 4001813607042bc4 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] is_bpf_text_address+0x36/0x1a0 kernel/bpf/core.c:772 kernel_text_address kernel/extable.c:125 [inline] kernel_text_address+0x8d/0x100 kernel/extable.c:94 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x59/0xa0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xa6/0x100 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_noprof+0x223/0x510 mm/slub.c:4339 kmalloc_noprof include/linux/slab.h:909 [inline] kmalloc_array_noprof include/linux/slab.h:948 [inline] constrain_params_by_rules+0x175/0xca0 sound/core/pcm_native.c:377 snd_pcm_hw_refine sound/core/pcm_native.c:567 [inline] snd_pcm_hw_refine+0x7de/0xad0 sound/core/pcm_native.c:545 snd_pcm_hw_param_min sound/core/oss/pcm_oss.c:249 [inline] snd_pcm_hw_param_near.constprop.0+0x58a/0x8e0 sound/core/oss/pcm_oss.c:405 snd_pcm_oss_change_params_locked+0x1398/0x3a30 sound/core/oss/pcm_oss.c:954 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1104 [inline] snd_pcm_oss_get_active_substream+0x168/0x1d0 sound/core/oss/pcm_oss.c:1121 snd_pcm_oss_get_formats+0x7e/0x340 sound/core/oss/pcm_oss.c:1842 snd_pcm_oss_set_format sound/core/oss/pcm_oss.c:1882 [inline] snd_pcm_oss_ioctl+0x2efb/0x37a0 sound/core/oss/pcm_oss.c:2647 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f162058e969 RSP: 002b:00007f16213ba038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f16207b5fa0 RCX: 00007f162058e969 RDX: 0000200000001180 RSI: 00000000c0045005 RDI: 0000000000000003 RBP: 00007f1620610ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f16207b5fa0 R15: 00007ffee0a0e378 rcu: rcu_preempt kthread starved for 10505 jiffies! g25773 f0x0 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:27688 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5392 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6781 __schedule_loop kernel/sched/core.c:6859 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6874 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 7726 Comm: sed Not tainted 6.15.0-syzkaller-08486-gf66bc387efbe #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xd0b/0x1490 kernel/smp.c:885 Code: e8 8a 12 0c 00 45 85 ed 74 46 48 8b 14 24 49 89 d6 49 89 d5 49 c1 ee 03 41 83 e5 07 4d 01 e6 41 83 c5 03 e8 27 17 0c 00 f3 90 <41> 0f b6 06 41 38 c5 7c 08 84 c0 0f 85 6f 05 00 00 8b 43 08 31 ff RSP: 0018:ffffc9000bac7948 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b85416a0 RCX: ffffffff81afb2dd RDX: ffff8880300ac880 RSI: ffffffff81afb2b9 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000 R13: 0000000000000003 R14: ffffed10170a82d5 R15: ffff8880b843cfc0 FS: 0000000000000000(0000) GS:ffff888124971000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6521817e9c CR3: 000000000e182000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x4a0/0x1790 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:480 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:470 [inline] tlb_flush_mmu mm/mmu_gather.c:403 [inline] tlb_finish_mmu+0x3c9/0x7c0 mm/mmu_gather.c:496 exit_mmap+0x403/0xb90 mm/mmap.c:1297 __mmput+0x12a/0x410 kernel/fork.c:1381 mmput+0x62/0x70 kernel/fork.c:1404 exit_mm kernel/exit.c:595 [inline] do_exit+0xa3a/0x2c70 kernel/exit.c:947 do_group_exit+0xd3/0x2a0 kernel/exit.c:1108 __do_sys_exit_group kernel/exit.c:1119 [inline] __se_sys_exit_group kernel/exit.c:1117 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1117 x64_sys_call+0x1530/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f65219766c5 Code: Unable to access opcode bytes at 0x7f652197669b. RSP: 002b:00007ffc03e9fd18 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f6521a77fe8 RCX: 00007f65219766c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6521a76680 R15: 00007f6521a78000