INFO: task syz.0.1133:4027 blocked for more than 138 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1133 state:D stack:0 pid:4027 tgid:4015 ppid:297 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:6026 [inline] __schedule+0x14ce/0x2100 kernel/sched/core.c:7893 __schedule_loop kernel/sched/core.c:7974 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7989 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+0x369/0x650 kernel/sched/completion.c:127 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148 rcu_barrier+0x415/0x540 kernel/rcu/tree.c:4657 netdev_run_todo+0x118/0xce0 net/core/dev.c:10900 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152 ppp_release+0xf5/0x200 drivers/net/ppp/ppp_generic.c:423 __fput+0x1fe/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e5/0x260 kernel/task_work.c:246 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x9ad/0x2720 kernel/exit.c:954 do_group_exit+0x229/0x2f0 kernel/exit.c:1096 get_signal+0x1398/0x14e0 kernel/signal.c:2933 arch_do_signal_or_restart+0xbc/0x760 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: 0033:0x7f9ca259ce59 RSP: 002b:00007f9ca34720e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f9ca2816098 RCX: 00007f9ca259ce59 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f9ca2816098 RBP: 00007f9ca2816090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9ca2816128 R14: 00007ffc7f369630 R15: 00007ffc7f369718 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 8a9cd2cbe126bd9938f6e7ac5eb01541012e42ba Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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+0xdad/0xf00 kernel/hung_task.c:423 kthread+0x2c9/0x370 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 4064 Comm: syz-executor Not tainted syzkaller #0 8a9cd2cbe126bd9938f6e7ac5eb01541012e42ba Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:memset_orig+0x46/0xb0 arch/x86/lib/memset_64.S:72 Code: 41 83 e1 07 75 70 48 89 d1 48 c1 e9 06 74 35 0f 1f 44 00 00 48 ff c9 48 89 07 48 89 47 08 48 89 47 10 48 89 47 18 48 89 47 20 <48> 89 47 28 48 89 47 30 48 89 47 38 48 8d 7f 40 75 d8 0f 1f 84 00 RSP: 0018:ffffc900106b7318 EFLAGS: 00000206 RAX: ffffffffffffffff RBX: ffffea0006909f40 RCX: 0000000000000006 RDX: 0000000000000200 RSI: 00000000000000ff RDI: ffffed103484fa40 RBP: ffffc900106b7320 R08: dffffc0000000000 R09: 0000000000000000 R10: ffffed103484fa00 R11: ffffed1021874bbc R12: 0000000000000001 R13: 0000000000000000 R14: 1ffff920020d6e70 R15: dffffc0000000000 FS: 0000555563fa7500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5e8c6324aa CR3: 000000015ec20000 CR4: 00000000003526b0 Call Trace: __kasan_poison_pages+0x31/0x40 mm/kasan/common.c:143 kasan_poison_pages include/linux/kasan.h:118 [inline] free_pages_prepare mm/page_alloc.c:1413 [inline] free_unref_page+0x354/0xf80 mm/page_alloc.c:2876 __free_pages+0x6b/0x3b0 mm/page_alloc.c:5402 __free_slab+0xb5/0x110 mm/slub.c:2758 free_slab+0x18/0xe0 mm/slub.c:2781 discard_slab+0x23/0x40 mm/slub.c:2787 __slab_free+0x1fd/0x2a0 mm/slub.c:4625 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_slab_alloc+0x28/0x90 mm/kasan/common.c:331 kasan_slab_alloc include/linux/kasan.h:251 [inline] slab_post_alloc_hook mm/slub.c:4202 [inline] slab_alloc_node mm/slub.c:4251 [inline] kmem_cache_alloc_noprof+0x1bf/0x410 mm/slub.c:4260 __kernfs_new_node+0xf1/0x740 fs/kernfs/dir.c:628 kernfs_new_node+0x154/0x280 fs/kernfs/dir.c:704 kernfs_create_dir_ns+0x4b/0x130 fs/kernfs/dir.c:1065 sysfs_create_dir_ns+0x127/0x210 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x71b/0xc30 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_init_and_add+0x12c/0x1a0 lib/kobject.c:457 rx_queue_add_kobject net/core/net-sysfs.c:1105 [inline] net_rx_queue_update_kobjects+0x1f5/0x5a0 net/core/net-sysfs.c:1160 register_queue_kobjects net/core/net-sysfs.c:1894 [inline] netdev_register_kobject+0x26d/0x360 net/core/net-sysfs.c:2139 register_netdevice+0xf92/0x19d0 net/core/dev.c:10609 tun_set_iff+0x83a/0xee0 drivers/net/tun.c:2865 __tun_chr_ioctl+0x861/0x1f60 drivers/net/tun.c:3134 tun_chr_ioctl+0x2e/0x40 drivers/net/tun.c:3421 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0x132/0x1b0 fs/ioctl.c:893 __x64_sys_ioctl+0x7f/0xa0 fs/ioctl.c:893 x64_sys_call+0x1878/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:47 [inline] do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f16c619caeb Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007fff6f164b60 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fff6f164c10 RCX: 00007f16c619caeb RDX: 00007fff6f164be0 RSI: 00000000400454ca RDI: 00000000000000c8 RBP: 00007f16c62336b1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008 R13: 0000000000000003 R14: 00007fff6f164f08 R15: 0000000000000000 net_ratelimit: 117414 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:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:06:c1:83:a8:79:6b, 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 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 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:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) net_ratelimit: 124402 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 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:1b, 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: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 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)