INFO: task syz.1.505:1758 blocked for more than 127 seconds. Not tainted 6.12.30-syzkaller-g3bff0858a069 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.505 state:D stack:0 pid:1758 tgid:1758 ppid:289 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x132b/0x1e00 kernel/sched/core.c:7789 __schedule_loop kernel/sched/core.c:7870 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7885 schedule_timeout+0xb2/0x3a0 kernel/time/timer.c:2595 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common+0x359/0x630 kernel/sched/completion.c:127 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148 __flush_work+0x6d2/0xac0 kernel/workqueue.c:4233 __cancel_work_sync kernel/workqueue.c:4354 [inline] cancel_work_sync+0xac/0xe0 kernel/workqueue.c:4391 uhid_dev_destroy drivers/hid/uhid.c:584 [inline] uhid_char_release+0xa7/0x600 drivers/hid/uhid.c:662 __fput+0x1fb/0xa00 fs/file_table.c:431 ____fput+0x20/0x30 fs/file_table.c:459 task_work_run+0x1e3/0x250 kernel/task_work.c:240 resume_user_mode_work+0x36/0x50 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+0x64/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f82def8e929 RSP: 002b:00007fffa5579958 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f82df1b7ba0 RCX: 00007f82def8e929 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f82df1b7ba0 R08: 0000000000000074 R09: 00000006a5579c4f R10: 00007f82df1b7ac0 R11: 0000000000000246 R12: 000000000000ee24 R13: 00007fffa5579a50 R14: ffffffffffffffff R15: 00007fffa5579a70 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.30-syzkaller-g3bff0858a069 #0 051941c7a2def972631bf72fe68480c4884f2578 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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+0x64/0xa0 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 6.12.30-syzkaller-g3bff0858a069 #0 051941c7a2def972631bf72fe68480c4884f2578 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:last_frame arch/x86/kernel/unwind_frame.c:82 [inline] RIP: 0010:is_last_frame arch/x86/kernel/unwind_frame.c:87 [inline] RIP: 0010:is_last_task_frame arch/x86/kernel/unwind_frame.c:156 [inline] RIP: 0010:unwind_next_frame+0xdf/0x750 arch/x86/kernel/unwind_frame.c:276 Code: 00 00 00 00 fc ff df 4c 89 6d c0 4c 89 7d b8 4c 89 75 d0 4c 8b 7b 38 4c 8d 73 28 4c 89 f0 48 c1 e8 03 48 89 45 a0 80 3c 10 00 <74> 12 4c 89 f7 e8 77 b7 97 00 48 ba 00 00 00 00 00 fc ff df 4c 89 RSP: 0018:ffffc9000022ffc8 EFLAGS: 00000246 RAX: 1ffff9200004600e RBX: ffffc90000230048 RCX: 0000000000230000 RDX: dffffc0000000000 RSI: ffffffff84f9d556 RDI: ffffc90000230048 RBP: ffffc90000230038 R08: ffffc90000230110 R09: ffffc90000230108 R10: 000000000000000c R11: ffffffff81740950 R12: 0000000000000000 R13: 1ffff92000046014 R14: ffffc90000230070 R15: ffffc900002308d0 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd431f7c4c CR3: 0000000109ff8000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x139/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9d/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x4a/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2413 [inline] slab_free mm/slub.c:4662 [inline] kmem_cache_free+0x1c1/0x510 mm/slub.c:4769 kfree_skbmem net/core/skbuff.c:-1 [inline] __kfree_skb+0x18f/0x210 net/core/skbuff.c:1215 consume_skb+0x65/0x1a0 net/core/skbuff.c:1446 netlink_broadcast_filtered+0x10e7/0x1200 net/netlink/af_netlink.c:1527 nlmsg_multicast_filtered include/net/netlink.h:1125 [inline] nlmsg_multicast include/net/netlink.h:1144 [inline] nlmsg_notify+0xf1/0x1b0 net/netlink/af_netlink.c:2580 rtnl_notify+0x9e/0xd0 net/core/rtnetlink.c:786 fdb_notify+0xce/0x150 net/bridge/br_fdb.c:206 br_fdb_update+0x4b7/0x680 net/bridge/br_fdb.c:941 br_handle_frame_finish+0x39c/0x1720 net/bridge/br_input.c:141 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+0xf4b/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:6202 __napi_poll+0xd3/0x610 net/core/dev.c:6853 napi_poll net/core/dev.c:6922 [inline] net_rx_action+0x584/0xce0 net/core/dev.c:7044 handle_softirqs+0x1ae/0x630 kernel/softirq.c:603 __do_softirq+0xf/0x16 kernel/softirq.c:641 do_softirq+0xa6/0x100 kernel/softirq.c:485 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:412 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_do_batch+0x5c6/0xd20 kernel/rcu/tree.c:2586 nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline] rcu_nocb_cb_kthread+0x4dc/0xac0 kernel/rcu/tree_nocb.h:957 kthread+0x2c7/0x370 kernel/kthread.c:389 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 net_ratelimit: 73128 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:b6:9c:3d:2c:12:6f, 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 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: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 veth0_to_bridge with own address as source address (addr:b6:9c:3d:2c:12:6f, 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)