INFO: task syz.6.7038:22409 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.7038 state:D stack:0 pid:22409 tgid:22370 ppid:22120 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285 device_lock include/linux/device.h:908 [inline] usbdev_open+0x171/0x840 drivers/usb/core/devio.c:1051 chrdev_open+0x4db/0x5f0 fs/char_dev.c:414 do_dentry_open+0x978/0x1510 fs/open.c:960 vfs_open+0x86/0x230 fs/open.c:1090 do_open fs/namei.c:3774 [inline] path_openat+0x2b6c/0x34b0 fs/namei.c:3933 do_filp_open+0x1c6/0x3e0 fs/namei.c:3960 do_sys_openat2+0x12c/0x1c0 fs/open.c:1438 do_sys_open fs/open.c:1453 [inline] __do_sys_openat fs/open.c:1469 [inline] __se_sys_openat fs/open.c:1464 [inline] __x64_sys_openat+0x13a/0x170 fs/open.c:1464 x64_sys_call+0xe69/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:258 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7ff05e38d510 RSP: 002b:00007ff05cdf6b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000010b701 RCX: 00007ff05e38d510 RDX: 000000000010b701 RSI: 00007ff05cdf6c10 RDI: 00000000ffffff9c RBP: 00007ff05cdf6c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007ff05e5d6128 R14: 00007ff05e5d6090 R15: 00007ffc6bc2af38 INFO: task syz.4.7073:22500 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.7073 state:D stack:0 pid:22500 tgid:22499 ppid:20913 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285 device_lock include/linux/device.h:908 [inline] usbdev_open+0x171/0x840 drivers/usb/core/devio.c:1051 chrdev_open+0x4db/0x5f0 fs/char_dev.c:414 do_dentry_open+0x978/0x1510 fs/open.c:960 vfs_open+0x86/0x230 fs/open.c:1090 do_open fs/namei.c:3774 [inline] path_openat+0x2b6c/0x34b0 fs/namei.c:3933 do_filp_open+0x1c6/0x3e0 fs/namei.c:3960 do_sys_openat2+0x12c/0x1c0 fs/open.c:1438 do_sys_open fs/open.c:1453 [inline] __do_sys_openat fs/open.c:1469 [inline] __se_sys_openat fs/open.c:1464 [inline] __x64_sys_openat+0x13a/0x170 fs/open.c:1464 x64_sys_call+0xe69/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:258 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f17ff38d510 RSP: 002b:00007f1800150b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000010b701 RCX: 00007f17ff38d510 RDX: 000000000010b701 RSI: 00007f1800150c10 RDI: 00000000ffffff9c RBP: 00007f1800150c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007f17ff5d6038 R14: 00007f17ff5d5fa0 R15: 00007fff5ca915c8 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 064bd8e71db8281f775729d9237f740d6717dea5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2bf/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+0xd8f/0xed0 kernel/hung_task.c:423 kthread+0x2c7/0x370 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: 832 Comm: kworker/1:4 Not tainted syzkaller #0 064bd8e71db8281f775729d9237f740d6717dea5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_power_efficient neigh_periodic_work RIP: 0010:clear_page_erms+0xb/0x30 arch/x86/lib/clear_page_64.S:50 Code: 48 8d 7f 40 75 d9 90 e9 43 6d 03 00 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 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc9000022ff98 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffea00040ce700 RCX: 0000000000000240 RDX: ffff88810339c000 RSI: 0000000000000001 RDI: ffff88810339cdc0 RBP: ffffc90000230060 R08: ffffea00040ce737 R09: 0000000000000000 R10: ffffed1020673800 R11: fffff94000819ce7 R12: 0000000000000001 R13: 1ffff92000045ff8 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f462473b000 CR3: 000000010ff36000 CR4: 00000000003526b0 Call Trace: prep_new_page+0x1c/0x120 mm/page_alloc.c:1834 get_page_from_freelist+0x48ce/0x4960 mm/page_alloc.c:3914 __alloc_pages_noprof+0x31f/0x7b0 mm/page_alloc.c:5258 alloc_slab_page+0x6b/0x1f0 mm/slub.c:-1 allocate_slab+0x69/0x440 mm/slub.c:2660 new_slab mm/slub.c:2714 [inline] ___slab_alloc+0x59a/0x8b0 mm/slub.c:3902 __slab_alloc mm/slub.c:3992 [inline] __slab_alloc_node mm/slub.c:4045 [inline] slab_alloc_node mm/slub.c:4206 [inline] kmem_cache_alloc_noprof+0x202/0x3a0 mm/slub.c:4227 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:190 [inline] br_flood+0x4ed/0x730 net/bridge/br_forward.c:236 br_handle_frame_finish+0x12bb/0x1720 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+0xf48/0x3940 net/core/dev.c:5651 __netif_receive_skb_one_core net/core/dev.c:5755 [inline] __netif_receive_skb net/core/dev.c:5870 [inline] process_backlog+0x3e5/0xae0 net/core/dev.c:6206 __napi_poll+0xd0/0x610 net/core/dev.c:6857 napi_poll net/core/dev.c:6926 [inline] net_rx_action+0x584/0xce0 net/core/dev.c:7048 handle_softirqs+0x1ab/0x630 kernel/softirq.c:621 __do_softirq+0xf/0x16 kernel/softirq.c:659 do_softirq+0xa6/0x100 kernel/softirq.c:503 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430 __raw_write_unlock_bh include/linux/rwlock_api_smp.h:281 [inline] _raw_write_unlock_bh+0x33/0x70 kernel/locking/spinlock.c:366 neigh_periodic_work+0xa73/0xbc0 net/core/neighbour.c:1019 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x7d5/0x1020 kernel/workqueue.c:3319 worker_thread+0xc58/0x1250 kernel/workqueue.c:3400 kthread+0x2c7/0x370 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 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: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 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:0c, 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:0c, 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:0c, 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: 148299 callbacks suppressed 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:0c, 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:0c, 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:0c, 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:0c, 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:0c, vlan:0)