syzbot

INFO: task syz-executor:2676 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:2676  tgid:2676  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6016 [inline]
 __schedule+0x1399/0x1fa0 kernel/sched/core.c:7870
 __schedule_loop kernel/sched/core.c:7951 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7966
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8023
 __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
 rtnl_lock net/core/rtnetlink.c:79 [inline]
 rtnetlink_rcv_msg+0x79e/0xa40 net/core/rtnetlink.c:6672
 netlink_rcv_skb+0x259/0x4f0 net/netlink/af_netlink.c:2545
 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6693
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x8c0/0xa60 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x7fe/0xb10 net/netlink/af_netlink.c:1889
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x718/0x790 net/socket.c:2216
 __do_sys_sendto net/socket.c:2228 [inline]
 __se_sys_sendto net/socket.c:2224 [inline]
 __x64_sys_sendto+0xe9/0x100 net/socket.c:2224
 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45
 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: 0033:0x7f2177f57917
RSP: 002b:00007ffef9659c20 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000055558e14d500 RCX: 00007f2177f57917
RDX: 0000000000000028 RSI: 00007f2178d44670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffef9659c84 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f2178d44670 R15: 0000000000000000
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 7beaeb3ad893ecbf8bcfcfada8847ce2a8dfc7fe
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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: 30 Comm: ksoftirqd/1 Not tainted syzkaller #0 7beaeb3ad893ecbf8bcfcfada8847ce2a8dfc7fe
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:stack_trace_consume_entry+0x0/0x2a0 kernel/stacktrace.c:83
Code: 8d 65 f0 5b 41 5e 5d e9 be 8a 2d 04 cc e8 98 2c 2b 04 0f 1f 84 00 00 00 00 00 b8 c9 ff 26 85 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 20 48
RSP: 0018:ffffc900001f6e00 EFLAGS: 00000257
RAX: ffffffff81dfa43f RBX: ffffc900001f6ec0 RCX: 00000000001f6e00
RDX: ffffc900001f7101 RSI: ffffffff81dfa43f RDI: ffffc900001f6ec0
RBP: ffffc900001f6e90 R08: ffffc900001f6ed0 R09: ffffc900001f6ec8
R10: 0000000000000000 R11: ffffffff8175d800 R12: ffff888103678000
R13: 0000000000000000 R14: ffffffff8175d800 R15: ffffc900001f6e08
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc361253b9d CR3: 000000010afb0000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 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_free_info+0x4a/0x60 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:249 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:266
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2445 [inline]
 slab_free mm/slub.c:4714 [inline]
 kmem_cache_free+0x1bd/0x4f0 mm/slub.c:4825
 kfree_skbmem net/core/skbuff.c:-1 [inline]
 __kfree_skb+0x18f/0x210 net/core/skbuff.c:1203
 sk_skb_reason_drop+0xd8/0x310 net/core/skbuff.c:1240
 kfree_skb_reason include/linux/skbuff.h:1271 [inline]
 kfree_skb include/linux/skbuff.h:1280 [inline]
 ip6_mc_input+0x516/0x6c0 net/ipv6/ip6_input.c:587
 dst_input include/net/dst.h:469 [inline]
 ip6_rcv_finish+0x363/0x3e0 net/ipv6/ip6_input.c:79
 NF_HOOK include/linux/netfilter.h:317 [inline]
 ipv6_rcv+0xf1/0x240 net/ipv6/ip6_input.c:309
 __netif_receive_skb_one_core net/core/dev.c:5776 [inline]
 __netif_receive_skb net/core/dev.c:5889 [inline]
 netif_receive_skb_internal net/core/dev.c:5975 [inline]
 netif_receive_skb+0x147/0x7b0 net/core/dev.c:6034
 br_netif_receive_skb net/bridge/br_input.c:30 [inline]
 NF_HOOK include/linux/netfilter.h:317 [inline]
 br_pass_frame_up+0x126/0x1b0 net/bridge/br_input.c:70
 br_handle_frame_finish+0x1317/0x1760 net/bridge/br_input.c:221
 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:5670
 __netif_receive_skb_one_core net/core/dev.c:5774 [inline]
 __netif_receive_skb net/core/dev.c:5889 [inline]
 process_backlog+0x3e5/0xad0 net/core/dev.c:6225
 __napi_poll+0xd0/0x610 net/core/dev.c:6876
 napi_poll net/core/dev.c:6945 [inline]
 net_rx_action+0x5ea/0xd80 net/core/dev.c:7067
 handle_softirqs+0x1ad/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
 </TASK>
net_ratelimit: 108952 callbacks suppressed
bridge0: received packet on veth1_to_bridge with own address as source address (addr:b2:a9:4f:3d:75:c3, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:b2:a9:4f:3d:75:c3, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
net_ratelimit: 134257 callbacks suppressed
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:b2:a9:4f:3d:75:c3, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:b2:a9:4f:3d:75:c3, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)