INFO: task syz.3.38:447 blocked for more than 124 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.38 state:D stack:0 pid:447 tgid:447 ppid:296 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:6054 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7867 __schedule_loop kernel/sched/core.c:7944 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7959 schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common+0x368/0x650 kernel/sched/completion.c:127 wait_for_completion_state+0x19/0x40 kernel/sched/completion.c:264 coredump_wait fs/coredump.c:448 [inline] do_coredump+0x885/0x3050 fs/coredump.c:629 get_signal+0x11bf/0x1490 kernel/signal.c:2918 arch_do_signal_or_restart+0xbc/0x700 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] irqentry_exit_to_user_mode+0x4d/0xb0 kernel/entry/common.c:231 irqentry_exit+0x16/0x60 kernel/entry/common.c:334 exc_page_fault+0x65/0xc0 arch/x86/mm/fault.c:1537 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f6c73653b27 RSP: 002b:00007ffe9b6a7220 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 0000000000000000 RDX: 00007ffe9b6a7240 RSI: 00007ffe9b6a7370 RDI: 000000000000000b RBP: 00007ffe9b7a5ff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 00007ffe9b7a6030 R13: 00007f6c73a2618c R14: 0000000000009ce2 R15: 00007f6c73a26180 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 a506770653dd131ce1f6b755c8f096a645f29717 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2ba/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline] watchdog+0xe45/0xf90 kernel/hung_task.c:423 kthread+0x2c7/0x360 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 1277 Comm: syz-executor Not tainted syzkaller #0 a506770653dd131ce1f6b755c8f096a645f29717 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 RIP: 0010:clear_page_erms+0xb/0x30 arch/x86/lib/clear_page_64.S:50 Code: 48 8d 7f 40 75 d9 90 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa b9 00 10 00 00 31 c0 aa e9 0e 7a 03 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000006ed8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 1ffff92000000de0 RCX: 0000000000000540 RDX: ffff888110e13000 RSI: 0000000000000001 RDI: ffff888110e13ac0 RBP: ffffc90000006f90 R08: ffffffff87e442ff R09: 0000000000000000 R10: ffffed10221c2600 R11: fffffbfff0fc8860 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3804b57e20 CR3: 000000010c384000 CR4: 00000000003526b0 Call Trace: prep_new_page+0x2d/0x180 mm/page_alloc.c:1871 get_page_from_freelist+0x4aea/0x4ba0 mm/page_alloc.c:3948 __alloc_pages_noprof+0x35a/0x7e0 mm/page_alloc.c:5315 alloc_slab_page+0x6b/0x1e0 mm/slub.c:-1 allocate_slab+0x69/0x430 mm/slub.c:2687 new_slab mm/slub.c:2741 [inline] ___slab_alloc+0x591/0x8c0 mm/slub.c:3934 __slab_alloc mm/slub.c:4025 [inline] __slab_alloc_node mm/slub.c:4078 [inline] slab_alloc_node mm/slub.c:4239 [inline] kmem_cache_alloc_node_noprof+0x29b/0x420 mm/slub.c:4305 __alloc_skb+0x10c/0x360 net/core/skbuff.c:677 alloc_skb include/linux/skbuff.h:1363 [inline] nlmsg_new include/net/netlink.h:1015 [inline] fdb_notify+0x78/0x150 net/bridge/br_fdb.c:195 br_fdb_update+0x5b7/0x6c0 net/bridge/br_fdb.c:951 br_handle_frame_finish+0x385/0x1620 net/bridge/br_input.c:141 nf_hook_bridge_pre net/bridge/br_input.c:301 [inline] br_handle_frame+0x5a5/0xba0 net/bridge/br_input.c:424 __netif_receive_skb_core+0xfc1/0x3a70 net/core/dev.c:5695 __netif_receive_skb_one_core net/core/dev.c:5799 [inline] __netif_receive_skb net/core/dev.c:5914 [inline] process_backlog+0x40b/0xaf0 net/core/dev.c:6250 __napi_poll+0xcd/0x600 net/core/dev.c:6901 napi_poll net/core/dev.c:6970 [inline] net_rx_action+0x5dc/0xd70 net/core/dev.c:7092 handle_softirqs+0x1aa/0x620 kernel/softirq.c:621 __do_softirq+0xf/0x16 kernel/softirq.c:659 do_softirq+0xb8/0x110 kernel/softirq.c:503 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline] _raw_spin_unlock_bh+0x54/0x60 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:396 [inline] addrconf_ifdown+0x60d/0x1970 net/ipv6/addrconf.c:3950 addrconf_notify+0x17a/0xeb0 net/ipv6/addrconf.c:-1 notifier_call_chain+0x106/0x2b0 kernel/notifier.c:93 raw_notifier_call_chain+0x31/0x40 kernel/notifier.c:461 call_netdevice_notifiers_info net/core/dev.c:2074 [inline] call_netdevice_notifiers_extack net/core/dev.c:2112 [inline] call_netdevice_notifiers net/core/dev.c:2126 [inline] unregister_netdevice_many_notify+0xde1/0x1be0 net/core/dev.c:11533 unregister_netdevice_many net/core/dev.c:11595 [inline] unregister_netdevice_queue+0x302/0x350 net/core/dev.c:11469 unregister_netdevice include/linux/netdevice.h:3165 [inline] __tun_detach+0xc98/0x1450 drivers/net/tun.c:685 tun_detach drivers/net/tun.c:701 [inline] tun_chr_close+0x93/0x150 drivers/net/tun.c:3520 __fput+0x20b/0xa30 fs/file_table.c:447 ____fput+0x20/0x30 fs/file_table.c:475 task_work_run+0x1e8/0x260 kernel/task_work.c:246 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xa46/0x2850 kernel/exit.c:955 do_group_exit+0x21f/0x2f0 kernel/exit.c:1098 get_signal+0x134c/0x1490 kernel/signal.c:2933 arch_do_signal_or_restart+0xbc/0x700 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x57/0xb0 kernel/entry/common.c:218 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f91f0158fd7 Code: Unable to access opcode bytes at 0x7f91f0158fad. RSP: 002b:00007ffcbd417b50 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: 0000000000000028 RBX: 0000555570c44500 RCX: 00007f91f0158fd7 RDX: 0000000000000028 RSI: 00007f91f0f54670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffcbd417bb4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f91f0f54670 R15: 0000000000000000 net_ratelimit: 95687 callbacks suppressed 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:ee:e7:e1:ef:9f:b3, 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) 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:ee:e7:e1:ef:9f:b3, 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) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 124790 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: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:ee:e7:e1:ef:9f:b3, 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) 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:ee:e7:e1:ef:9f:b3, 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)