INFO: task syz.5.3414:10770 blocked for more than 126 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.3414 state:D stack:0 pid:10770 tgid:10769 ppid:6804 flags:0x00004004 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 super_lock+0x168/0x330 fs/super.c:117 super_lock_shared fs/super.c:142 [inline] iterate_supers+0x8a/0x560 fs/super.c:937 ksys_sync+0xa1/0x170 fs/sync.c:103 __ia32_sys_sync+0x12/0x20 fs/sync.c:114 x64_sys_call+0x2a58/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:163 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: 0033:0x7f9966b9ce59 RSP: 002b:00007f9967a1d028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f9966e15fa0 RCX: 00007f9966b9ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f9966e15fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9966e16038 R14: 00007f9966e15fa0 R15: 00007fffb14f5a48 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 46888e5e5e1e1e111dd74017fc0802fda26c1cfc 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: 20 Comm: rcuop/0 Not tainted syzkaller #0 46888e5e5e1e1e111dd74017fc0802fda26c1cfc Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:60 [inline] RIP: 0010:update_stack_state+0x1e6/0x4b0 arch/x86/kernel/unwind_frame.c:228 Code: 89 dc 44 8b 2b 45 85 ed 0f 95 c0 48 8b 55 b0 4c 39 fa 0f 93 c1 20 c1 4c 39 f2 0f 92 c0 20 c8 3c 01 75 17 48 8b 8d 78 ff ff ff <4c> 39 f9 0f 97 c0 4c 39 f1 0f 96 c1 84 c8 75 6e 49 bd 00 00 00 00 RSP: 0018:ffffc9000022fb58 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffc9000022fca8 RCX: ffffc90000230cf0 RDX: ffffc90000230ce0 RSI: 1ffff92000045f96 RDI: ffffc9000022fd00 RBP: ffffc9000022fc18 R08: ffffc9000022fd70 R09: ffffc9000022fd68 R10: 000000000000000e R11: ffffffff8175f3a0 R12: ffffc9000022fca8 R13: 0000000000000002 R14: ffffc90000231000 R15: ffffc90000229000 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb372d47e20 CR3: 000000012ec08000 CR4: 00000000003526b0 Call Trace: unwind_next_frame+0x3c1/0x750 arch/x86/kernel/unwind_frame.c:315 arch_stack_walk+0x138/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:49 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:70 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:565 unpoison_slab_object mm/kasan/common.c:321 [inline] __kasan_slab_alloc+0x73/0x90 mm/kasan/common.c:347 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 skb_clone+0x229/0x460 net/core/skbuff.c:2082 dev_queue_xmit_nit+0x1ad/0xae0 net/core/dev.c:2393 xmit_one net/core/dev.c:3686 [inline] dev_hard_start_xmit+0x187/0x760 net/core/dev.c:3709 __dev_queue_xmit+0x1927/0x3680 net/core/dev.c:4549 dev_queue_xmit include/linux/netdevice.h:3141 [inline] br_dev_queue_push_xmit+0x55c/0x700 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:317 [inline] br_forward_finish net/bridge/br_forward.c:66 [inline] NF_HOOK include/linux/netfilter.h:317 [inline] __br_forward+0x25c/0x390 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] br_flood+0x67e/0x730 net/bridge/br_forward.c:246 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+0xfae/0x3ab0 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+0x3e5/0xad0 net/core/dev.c:6250 __napi_poll+0xd3/0x610 net/core/dev.c:6901 napi_poll net/core/dev.c:6970 [inline] net_rx_action+0x5ea/0xd80 net/core/dev.c:7092 handle_softirqs+0x1aa/0x630 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 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_do_batch+0x5d9/0xd40 kernel/rcu/tree.c:2594 nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline] rcu_nocb_cb_kthread+0x524/0xb30 kernel/rcu/tree_nocb.h:957 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: 106543 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 veth0_to_bridge with own address as source address (addr:8e:98:7e:c7:c6:47, 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:8e:98:7e:c7:c6:47, 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:8e:98:7e:c7:c6:47, 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:8e:98:7e:c7:c6:47, vlan:0) net_ratelimit: 117204 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 veth0_to_bridge with own address as source address (addr:8e:98:7e:c7:c6:47, 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:8e:98:7e:c7:c6:47, 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:8e:98:7e:c7:c6:47, 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:8e:98:7e:c7:c6:47, vlan:0)