syzbot

INFO: task syz.4.1883:6044 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1883      state:D stack:0     pid:6044  tgid:6044  ppid:1280   flags:0x00004006
Call Trace:
 <TASK>
 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
 tun_detach drivers/net/tun.c:704 [inline]
 tun_chr_close+0xc5/0x150 drivers/net/tun.c:3520
 __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
 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: 0033:0x7f35ca75d60e
RSP: 002b:00007f35cb61ff58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f35cb6206c0 RCX: 00007f35ca75d60e
RDX: 00007f35cb61ffb0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f35ca832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f35caa16038 R14: 00007f35caa15fa0 R15: 00007ffc3954aba8
 </TASK>
INFO: task syz-executor:8559 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:8559  tgid:8559  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 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
 tun_detach drivers/net/tun.c:704 [inline]
 tun_chr_close+0xc5/0x150 drivers/net/tun.c:3520
 __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
 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: 0033:0x7f4a42f57f57
RSP: 002b:00007ffe4336dcb0 EFLAGS: 00000202 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 000055555f645500 RCX: 00007f4a42f57f57
RDX: 0000000040000000 RSI: 00007ffe4336dd3c RDI: ffffffffffffffff
RBP: 00007ffe4336dd3c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000035
R13: 000055555f6588d0 R14: 0000000000074d28 R15: 00007ffe4336dd90
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 59845a3e7facf6968a53e2150c0cf8787c039bda
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 __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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 33 Comm: rcuop/1 Not tainted syzkaller #0 59845a3e7facf6968a53e2150c0cf8787c039bda
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:rol32 include/linux/bitops.h:126 [inline]
RIP: 0010:jhash2 include/linux/jhash.h:129 [inline]
RIP: 0010:hash_stack lib/stackdepot.c:514 [inline]
RIP: 0010:stack_depot_save_flags+0x9d/0x800 lib/stackdepot.c:614
Code: f2 03 0a 03 42 04 44 03 62 08 44 89 e7 c1 c7 04 44 29 e1 31 cf 41 01 c4 29 f8 41 89 f8 41 c1 c0 06 41 31 c0 44 01 e7 45 89 c1 <41> c1 c1 08 45 29 c4 45 31 e1 41 01 f8 44 29 cf 44 89 c9 c1 c1 10
RSP: 0018:ffffc9000022fd70 EFLAGS: 00000213
RAX: 000000005e2d74cf RBX: 0000000000000820 RCX: 000000002befe6ac
RDX: ffffc9000022fe28 RSI: 0000000000000014 RDI: 0000000034546cb5
RBP: ffffc9000022fdd0 R08: 000000006099e7d5 R09: 000000006099e7d5
R10: 0000000000000013 R11: ffffffff8175e9a0 R12: 00000000cb599a69
R13: 0000000004b6cc01 R14: ffffc9000022fde0 R15: ffffc9000022fde0
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f92e81f84c0 CR3: 000000010cbb4000 CR4: 00000000003526b0
Call Trace:
 <IRQ>
 kasan_save_stack mm/kasan/common.c:50 [inline]
 kasan_save_track+0x4f/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:3674 [inline]
 dev_hard_start_xmit+0x187/0x760 net/core/dev.c:3697
 __dev_queue_xmit+0x1927/0x3680 net/core/dev.c:4537
 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]
 maybe_deliver net/bridge/br_forward.c:191 [inline]
 br_flood+0x50e/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
 __do_softirq+0xf/0x16 kernel/softirq.c:659
 do_softirq+0xb8/0x110 kernel/softirq.c:503
 </IRQ>
 <TASK>
 __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
 </TASK>
net_ratelimit: 72554 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: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: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: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 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)
net_ratelimit: 94551 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 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 veth0_to_bridge with own address as source address (addr:ae:bb:51:a2:76:fc, 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 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)