INFO: task syz.2.161:687 blocked for more than 124 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.161 state:D stack:0 pid:687 tgid:687 ppid:291 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:6026 [inline] __schedule+0x1399/0x1fa0 kernel/sched/core.c:7880 __schedule_loop kernel/sched/core.c:7961 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7976 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8033 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 tty_lock+0x70/0xa0 drivers/tty/tty_mutex.c:18 tty_release+0x80/0x1230 drivers/tty/tty_io.c:1736 __fput+0x1fb/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e5/0x260 kernel/task_work.c:246 resume_user_mode_work+0x35/0x50 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [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+0x63/0xb0 kernel/entry/common.c:218 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f8649f9cdd9 RSP: 002b:00007ffedd324bc8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f864a217da0 RCX: 00007f8649f9cdd9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f864a217da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007f864a217cb0 R11: 0000000000000246 R12: 0000000000009c64 R13: 00007f864a215fac R14: 0000000000009995 R15: 00007ffedd324cd0 INFO: task syz.2.161:688 blocked for more than 125 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.161 state:D stack:0 pid:688 tgid:687 ppid:291 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:6026 [inline] __schedule+0x1399/0x1fa0 kernel/sched/core.c:7880 __schedule_loop kernel/sched/core.c:7961 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7976 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8033 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 rcu_barrier+0x4d/0x540 kernel/rcu/tree.c:4589 netdev_run_todo+0x118/0xce0 net/core/dev.c:10900 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152 unregister_netdev+0x166/0x1d0 net/core/dev.c:11602 unregister_candev+0x19/0x30 drivers/net/can/dev/dev.c:582 slcan_close+0x82/0x150 drivers/net/can/slcan/slcan-core.c:880 tty_ldisc_close drivers/tty/tty_ldisc.c:455 [inline] tty_ldisc_kill drivers/tty/tty_ldisc.c:613 [inline] tty_ldisc_hangup+0x4dc/0x6e0 drivers/tty/tty_ldisc.c:729 __tty_hangup+0x585/0x810 drivers/tty/tty_io.c:624 tty_vhangup drivers/tty/tty_io.c:694 [inline] tty_ioctl+0x7c9/0xec0 drivers/tty/tty_io.c:2743 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: 0033:0x7f8649f9cdd9 RSP: 002b:00007f86489f7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f864a215fa0 RCX: 00007f8649f9cdd9 RDX: 0000000000000000 RSI: 0000000000005437 RDI: 0000000000000004 RBP: 00007f864a032d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f864a216038 R14: 00007f864a215fa0 R15: 00007ffedd324a68 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 364e5b4a04fa33eb2ecf1d01a1774d560d6f7c3f 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 17 Comm: ksoftirqd/0 Not tainted syzkaller #0 364e5b4a04fa33eb2ecf1d01a1774d560d6f7c3f Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:stack_depot_save+0x4/0x20 lib/stackdepot.c:685 Code: 00 00 4c 89 ea 4d 89 fa e9 5b fa ff ff 66 0f 1f 84 00 00 00 00 00 b8 a4 84 d6 8d 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <55> 48 89 e5 b9 01 00 00 00 e8 de f7 ff ff 5d c3 cc cc cc cc cc 0f RSP: 0018:ffffc90000116b98 EFLAGS: 00000246 RAX: 0000000000000010 RBX: ffff888103652c00 RCX: 7b2c92dc257ed900 RDX: 0000000000152820 RSI: 0000000000000010 RDI: ffffc90000116be0 RBP: ffffc90000116cd0 R08: ffffc90000116b30 R09: ffffc90000116b28 R10: 000000000000000f R11: ffffffff8175e9a0 R12: dffffc0000000000 R13: 1ffff110206ca580 R14: ffffc90000116be0 R15: 1ffff92000022d78 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc9dc36e0c CR3: 000000010ff20000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000071 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __set_page_owner+0x8e/0x600 mm/page_owner.c:338 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook+0x37d/0x3b0 mm/page_alloc.c:1863 prep_new_page+0x2d/0x190 mm/page_alloc.c:1871 get_page_from_freelist+0x496e/0x4a20 mm/page_alloc.c:3948 __alloc_pages_noprof+0x35f/0x7e0 mm/page_alloc.c:5312 alloc_slab_page+0x6b/0x1e0 mm/slub.c:-1 allocate_slab+0x69/0x420 mm/slub.c:2687 new_slab mm/slub.c:2741 [inline] ___slab_alloc+0x5a2/0x8d0 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_noprof+0x290/0x410 mm/slub.c:4260 skb_clone+0x229/0x460 net/core/skbuff.c:2082 deliver_clone net/bridge/br_forward.c:125 [inline] maybe_deliver net/bridge/br_forward.c:191 [inline] br_flood+0x4ed/0x730 net/bridge/br_forward.c:237 br_handle_frame_finish+0x11eb/0x17a0 net/bridge/br_input.c:215 nf_hook_bridge_pre net/bridge/br_input.c:301 [inline] br_handle_frame+0x5a6/0xba0 net/bridge/br_input.c:424 __netif_receive_skb_core+0xfb1/0x3ab0 net/core/dev.c:5683 __netif_receive_skb_one_core net/core/dev.c:5787 [inline] __netif_receive_skb net/core/dev.c:5902 [inline] process_backlog+0x3e5/0xad0 net/core/dev.c:6238 __napi_poll+0xd3/0x610 net/core/dev.c:6889 napi_poll net/core/dev.c:6958 [inline] net_rx_action+0x5ea/0xd80 net/core/dev.c:7080 handle_softirqs+0x1aa/0x630 kernel/softirq.c:621 run_ksoftirqd+0x20/0x30 kernel/softirq.c:999 smpboot_thread_fn+0x492/0x8b0 kernel/smpboot.c:164 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 net_ratelimit: 98543 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:6e:db:81:f5:f1:ce, 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 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:6e:db:81:f5:f1:ce, 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) net_ratelimit: 130597 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 veth0_to_bridge with own address as source address (addr:6e:db:81:f5:f1:ce, 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) bridge0: received packet on veth0_to_bridge with own address as source address (addr:6e:db:81:f5:f1:ce, 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 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)