rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5188/1:b..l rcu: (detected by 1, t=10503 jiffies, g=60681, q=208 ncpus=2) task:klogd state:R running task stack:24224 pid:5188 tgid:5188 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0xe55/0x5730 kernel/sched/core.c:6690 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6869 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194 sock_def_readable+0x160/0x610 net/core/sock.c:3442 unix_dgram_sendmsg+0xfa9/0x19e0 net/unix/af_unix.c:2167 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg net/socket.c:744 [inline] __sys_sendto+0x479/0x4d0 net/socket.c:2214 __do_sys_sendto net/socket.c:2226 [inline] __se_sys_sendto net/socket.c:2222 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2222 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: 0033:0x7fa44052f9b5 RSP: 002b:00007ffdf05d5258 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa44052f9b5 RDX: 0000000000000049 RSI: 000055759f20b8b0 RDI: 0000000000000003 RBP: 000055759f2022c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013 R13: 00007fa4406bd212 R14: 00007ffdf05d5358 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 5510 jiffies! g60681 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:27120 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0xe55/0x5730 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6782 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247 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: 5907 Comm: kworker/0:6 Not tainted 6.12.0-rc5-syzkaller-00047-g4236f913808c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events dvb_usb_read_remote_control RIP: 0010:unwind_next_frame+0x1567/0x20c0 arch/x86/kernel/unwind_orc.c:648 Code: 89 e2 48 89 c5 48 c1 ea 03 48 b8 00 00 00 00 00 fc ff df 80 3c 02 00 0f 84 3b f8 ff ff 4c 89 e7 e8 ce a0 b1 00 e9 2e f8 ff ff <48> 8d 79 02 48 ba 00 00 00 00 00 fc ff df 48 89 f8 48 c1 e8 03 0f RSP: 0018:ffffc90000006c68 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff90f483c4 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffc90000006d20 R08: ffffc90000006d0c R09: ffffffff90f483c8 R10: ffffc90000006cd8 R11: 0000000000006de8 R12: ffffc90000006d28 R13: ffffc90000006cd8 R14: ffffc90002fbfba0 R15: ffffc90002fbfb98 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb954362220 CR3: 000000000df7c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x95/0x100 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:319 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_noprof+0x121/0x2f0 mm/slub.c:4141 skb_ext_maybe_cow net/core/skbuff.c:6942 [inline] skb_ext_add+0xf8/0x770 net/core/skbuff.c:7016 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:169 [inline] br_nf_forward_ip.part.0+0x28/0x820 net/bridge/br_netfilter_hooks.c:709 br_nf_forward_ip net/bridge/br_netfilter_hooks.c:704 [inline] br_nf_forward+0xd9c/0x1bd0 net/bridge/br_netfilter_hooks.c:798 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626 nf_hook+0x474/0x7d0 include/linux/netfilter.h:269 NF_HOOK include/linux/netfilter.h:312 [inline] __br_forward+0x1be/0x5b0 net/bridge/br_forward.c:115 deliver_clone+0x5b/0xa0 net/bridge/br_forward.c:131 maybe_deliver+0xa7/0x120 net/bridge/br_forward.c:190 br_flood+0x17e/0x5c0 net/bridge/br_forward.c:236 br_handle_frame_finish+0xda5/0x1c80 net/bridge/br_input.c:215 br_nf_hook_thresh+0x303/0x410 net/bridge/br_netfilter_hooks.c:1195 br_nf_pre_routing_finish+0xafd/0x1d00 net/bridge/br_netfilter_hooks.c:450 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] br_nf_pre_routing+0xf7b/0x15b0 net/bridge/br_netfilter_hooks.c:559 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:277 [inline] br_handle_frame+0x9eb/0x1490 net/bridge/br_input.c:424 __netif_receive_skb_core.constprop.0+0xa3d/0x4330 net/core/dev.c:5560 __netif_receive_skb_one_core+0xb1/0x1e0 net/core/dev.c:5664 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5779 process_backlog+0x443/0x15f0 net/core/dev.c:6111 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6775 napi_poll net/core/dev.c:6844 [inline] net_rx_action+0xa92/0x1010 net/core/dev.c:6966 handle_softirqs+0x213/0x8f0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2042 [inline] RIP: 0010:vprintk_emit+0x621/0x6f0 kernel/printk/printk.c:2406 Code: 85 ed 0f 85 81 00 00 00 e8 cc d7 1f 00 9c 41 5c 41 81 e4 00 02 00 00 31 ff 4c 89 e6 e8 28 da 1f 00 4d 85 e4 0f 85 8d 00 00 00 aa d7 1f 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00 RSP: 0018:ffffc90002fbfad8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000017 RCX: ffffffff816da54e RDX: ffff8880309fa440 RSI: ffffffff816da558 RDI: 0000000000000007 RBP: 1ffff920005f7f5d R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000200 R14: ffff88801d6e8000 R15: ffffc90002fbfbc0 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:68 _printk+0xc8/0x100 kernel/printk/printk.c:2432 m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline] m920x_rc_core_query+0x2d7/0x500 drivers/media/usb/dvb-usb/m920x.c:229 dvb_usb_read_remote_control+0xda/0x1c0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 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 net_ratelimit: 46281 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:d6:1b:65:22:f0:ff, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 42068 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:d6:1b:65:22:f0:ff, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)