bridge0: received packet on gretap1 with own address as source address (addr:16:18:f0:35:6f:2b, vlan:0) bridge0: received packet on gretap1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on gretap1 with own address as source address (addr:16:18:f0:35:6f:2b, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=f904/1/0x4000000000000000 softirq=35236/35236 fqs=1 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9306/1:b..l rcu: (detected by 0, t=10502 jiffies, g=27473, q=214 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9299 Comm: syz.5.1104 Not tainted 6.15.0-rc1-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:hlock_class kernel/locking/lockdep.c:233 [inline] RIP: 0010:mark_lock+0x4a/0x1b0 kernel/locking/lockdep.c:4732 Code: 83 f5 09 eb 0b 89 d5 83 fa 20 0f 83 5d 01 00 00 bb 01 00 00 00 89 e9 d3 e3 41 8b 47 20 25 ff 1f 00 00 48 0f a3 05 26 14 d1 12 <73> 10 48 69 c0 c8 00 00 00 48 8d 80 c0 36 11 94 eb 38 83 3d 3d a3 RSP: 0018:ffffc90000a08b48 EFLAGS: 00000003 RAX: 000000000000006d RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff888026380b40 RDI: ffff888026380000 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888026380b60 R13: 0000000000000000 R14: ffff888026380000 R15: ffff888026380b40 FS: 00007f120467d6c0(0000) GS:ffff888125096000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000bf030 CR3: 000000001251e000 CR4: 0000000000350ef0 Call Trace: mark_usage kernel/locking/lockdep.c:4640 [inline] __lock_acquire+0x641/0xd80 kernel/locking/lockdep.c:5189 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xd3/0x120 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1765 [inline] __hrtimer_run_queues+0x67b/0xd40 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x112/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x167/0x2f0 arch/x86/include/asm/irqflags.h:-1 Code: c7 44 24 10 00 00 00 00 9c 8f 44 24 10 f7 44 24 10 00 02 00 00 0f 85 fd 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 65 48 8b 45 00 <48> 3b 44 24 38 0f 85 72 01 00 00 48 83 c4 40 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9001ce0f628 EFLAGS: 00000206 RAX: 0fd5b5fa19826200 RBX: ffff88804c8cadb8 RCX: 0fd5b5fa19826200 RDX: 0000000000000000 RSI: ffffffff8e4fd4cc RDI: ffffffff8ca1b620 RBP: ffffffff9368a020 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000246 R15: 0000000000000001 mutex_trylock+0x84/0x130 kernel/locking/mutex.c:1087 rxrpc_recvmsg+0x979/0x1840 net/rxrpc/recvmsg.c:366 sock_recvmsg_nosec+0x190/0x1d0 net/socket.c:1017 ____sys_recvmsg+0x3d4/0x480 net/socket.c:2784 ___sys_recvmsg net/socket.c:2828 [inline] do_recvmmsg+0x428/0xab0 net/socket.c:2923 __sys_recvmmsg net/socket.c:2997 [inline] __do_sys_recvmmsg net/socket.c:3020 [inline] __se_sys_recvmmsg net/socket.c:3013 [inline] __x64_sys_recvmmsg+0x1ab/0x260 net/socket.c:3013 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f120378d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f120467d038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f12039a5fa0 RCX: 00007f120378d169 RDX: 000000000000f000 RSI: 0000200000000d00 RDI: 0000000000000003 RBP: 00007f120380e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000010002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f12039a5fa0 R15: 00007fff1b869b08 task:syz.0.1107 state:R running task stack:26728 pid:9306 tgid:9305 ppid:5840 task_flags:0x400040 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x167/0x2f0 arch/x86/include/asm/irqflags.h:-1 Code: c7 44 24 10 00 00 00 00 9c 8f 44 24 10 f7 44 24 10 00 02 00 00 0f 85 fd 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 65 48 8b 45 00 <48> 3b 44 24 38 0f 85 72 01 00 00 48 83 c4 40 5b 41 5c 41 5d 41 5e RSP: 0000:ffffc9001ede7838 EFLAGS: 00000206 RAX: b8950bca3bdf2600 RBX: ffffffff8ed3dfe0 RCX: b8950bca3bdf2600 RDX: 0000000000000000 RSI: ffffffff8e4fd4cc RDI: ffffffff8ca1b620 RBP: ffffffff9368a020 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000002 R14: 0000000000000246 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] blk_cgroup_congested+0x38/0x200 block/blk-cgroup.c:2255 __folio_throttle_swaprate+0x84/0x1d0 mm/swapfile.c:3905 folio_throttle_swaprate include/linux/swap.h:634 [inline] folio_prealloc+0x107/0x170 mm/memory.c:1065 alloc_anon_folio mm/memory.c:4943 [inline] do_anonymous_page mm/memory.c:5000 [inline] do_pte_missing mm/memory.c:4158 [inline] handle_pte_fault+0x2e45/0x61c0 mm/memory.c:5997 __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1129/0x1bf0 mm/memory.c:6309 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline] handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x45b/0x920 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fb64b04fc90 RSP: 002b:00007fb64bfc04a0 EFLAGS: 00010282 RAX: 00000000000b0000 RBX: 00007fb64bfc0540 RCX: 0000000000000016 RDX: 00000000000005ff RSI: 0000000000000200 RDI: 00007fb64bfc05e0 RBP: 00000000000000e8 R08: 00007fb640a00000 R09: 00000000000000fe R10: 000020000001c902 R11: 0000000000009845 R12: 0000000000000181 R13: 00007fb64b2293e0 R14: 0000000000000011 R15: 00007fb64bfc05e0 rcu: rcu_preempt kthread starved for 10500 jiffies! g27473 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:25512 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 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: 13 Comm: kworker/u8:1 Not tainted 6.15.0-rc1-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: netns cleanup_net RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_single+0x461/0x1990 kernel/smp.c:679 Code: 55 22 0c 00 41 83 e4 01 75 16 e8 0a 1e 0c 00 4d 89 fc 44 8b 7c 24 24 eb 46 e8 fb 1d 0c 00 eb 3f 4d 89 fc 44 8b 7c 24 24 f3 90 <42> 0f b6 04 2b 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 d8 1d 0c RSP: 0018:ffffc900001275c0 EFLAGS: 00000293 RAX: ffffffff81b73748 RBX: 1ffff92000024ed5 RCX: ffff88801c680000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000127758 R08: ffffffff81b7370b R09: 1ffffffff20bfbee R10: dffffc0000000000 R11: ffffffff816b6a80 R12: ffffffff9368a020 R13: dffffc0000000000 R14: ffffc900001276a8 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124f96000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3fdf0d56c0 CR3: 0000000065642000 CR4: 0000000000350ef0 Call Trace: rcu_barrier+0x327/0x530 kernel/rcu/tree.c:3826 netdev_wait_allrefs_any net/core/dev.c:11213 [inline] netdev_run_todo+0x902/0xf30 net/core/dev.c:11305 default_device_exit_batch+0x804/0x880 net/core/dev.c:12537 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x8b1/0xd60 net/core/net_namespace.c:654 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac5/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245