INFO: task syz.2.2325:6003 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.2325 state:D stack:0 pid:6003 tgid:6002 ppid:5825 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:6053 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7866 __schedule_loop kernel/sched/core.c:7943 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7958 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+0x1c/0x40 kernel/sched/completion.c:148 rcu_barrier+0x45a/0x580 kernel/rcu/tree.c:4657 netdev_run_todo+0x118/0xce0 net/core/dev.c:10912 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0xc5/0x150 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: 0033:0x7fb190d9de59 RSP: 002b:00007fb191bba028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 0000000000000034 RBX: 00007fb191025fa0 RCX: 00007fb190d9de59 RDX: 0000000000004040 RSI: 0000200000000b40 RDI: 0000000000000003 RBP: 00007fb190e33e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb191026038 R14: 00007fb191025fa0 R15: 00007ffe06e0f968 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 5e823d74124d9c17bee2b333d3eb538db5552cb2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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: 440 Comm: kworker/u8:25 Not tainted syzkaller #0 5e823d74124d9c17bee2b333d3eb538db5552cb2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: netns cleanup_net RIP: 0010:kasan_check_range+0x4/0x2b0 mm/kasan/generic.c:188 Code: 52 e2 c5 03 cc 0f 0b b8 ea ff ff ff e9 45 e2 c5 03 cc cc cc cc cc b8 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 01 48 85 f6 0f 84 c0 01 00 00 55 48 89 e5 41 57 41 56 41 55 41 RSP: 0018:ffffc9000c3c7310 EFLAGS: 00000282 RAX: ffff88814c75801c RBX: ffff88814c75801c RCX: ffffffff81e6593b RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88814c75801c RBP: ffffc9000c3c7318 R08: ffff888107ddb66f R09: 1ffff11020fbb6cd R10: dffffc0000000000 R11: ffffed1020fbb6ce R12: 0000000000000001 R13: ffff888107ddb6ac R14: 0000000000000284 R15: ffff88814c758000 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbadb464087 CR3: 0000000111022000 CR4: 00000000003526b0 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline] __refcount_sub_and_test include/linux/refcount.h:389 [inline] refcount_sub_and_test include/linux/refcount.h:427 [inline] dec_stack_record_count mm/page_owner.c:245 [inline] __reset_page_owner+0x34b/0x450 mm/page_owner.c:328 reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1390 [inline] free_unref_page+0xbb8/0xf70 mm/page_alloc.c:2876 __free_pages+0x6b/0x3b0 mm/page_alloc.c:5402 __free_slab+0xb2/0x110 mm/slub.c:2758 free_slab+0x18/0xe0 mm/slub.c:2781 discard_slab mm/slub.c:2787 [inline] __put_partials+0x115/0x150 mm/slub.c:3256 put_cpu_partial+0x91/0xc0 mm/slub.c:3331 __slab_free+0x1cf/0x2a0 mm/slub.c:4584 do_slab_free mm/slub.c:4666 [inline] ___cache_free+0xc9/0xe0 mm/slub.c:4781 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0xb5/0x130 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x180 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x28/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:261 [inline] __do_kmalloc_node mm/slub.c:4395 [inline] __kmalloc_node_track_caller_noprof+0x24e/0x4f0 mm/slub.c:4414 kmalloc_reserve+0x144/0x4f0 net/core/skbuff.c:618 __alloc_skb+0x13f/0x360 net/core/skbuff.c:687 alloc_skb include/linux/skbuff.h:1363 [inline] nlmsg_new include/net/netlink.h:1015 [inline] rtmsg_ifinfo_build_skb+0x7a/0x270 net/core/rtnetlink.c:4106 rtmsg_ifinfo_event net/core/rtnetlink.c:4148 [inline] rtmsg_ifinfo+0x91/0x1a0 net/core/rtnetlink.c:4157 dev_close_many+0x27b/0x4f0 net/core/dev.c:1666 unregister_netdevice_many_notify+0x4bd/0x1be0 net/core/dev.c:11507 unregister_netdevice_many+0x1d/0x30 net/core/dev.c:11595 cleanup_net+0x640/0xc90 net/core/net_namespace.c:637 process_one_work kernel/workqueue.c:3273 [inline] process_scheduled_works+0x7f7/0x1060 kernel/workqueue.c:3354 worker_thread+0xc99/0x13f0 kernel/workqueue.c:3435 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 net_ratelimit: 76169 callbacks suppressed bridge0: received packet on veth0_to_bridge 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:1b, vlan:0) bridge0: received packet on veth0_to_bridge 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:1b, vlan:0) bridge0: received packet on veth0_to_bridge 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:1b, vlan:0) bridge0: received packet on veth0_to_bridge 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:1b, vlan:0) bridge0: received packet on veth0_to_bridge 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:1b, vlan:0)