syzbot

INFO: task syz-executor:10767 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:10767 tgid:10767 ppid:1      flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6016 [inline]
 __schedule+0x134f/0x1ea0 kernel/sched/core.c:7864
 __schedule_loop kernel/sched/core.c:7945 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7960
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8017
 __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+0x256/0x4f0 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+0x8c3/0xa60 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: 0033:0x7f5eb8d57917
RSP: 002b:00007ffee3233270 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000055555b7b7500 RCX: 00007f5eb8d57917
RDX: 0000000000000028 RSI: 00007f5eb9b44670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffee32332d4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f5eb9b44670 R15: 0000000000000000
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 93fdfe3663caa6d824c2578ca6c3b1aacfeda3e9
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+0x64/0xa0 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: 100 Comm: klogd Not tainted syzkaller #0 93fdfe3663caa6d824c2578ca6c3b1aacfeda3e9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:update_stack_state+0x363/0x4b0 arch/x86/kernel/unwind_frame.c:243
Code: 00 00 4c 8d 73 38 4c 89 f0 48 c1 e8 03 49 bc 00 00 00 00 00 fc ff df 42 80 3c 20 00 74 08 4c 89 f7 e8 11 b7 9a 00 48 8b 45 d0 <49> 89 06 48 8b 45 98 42 80 3c 20 00 4c 8b 75 c8 4c 8b 6d c0 74 08
RSP: 0018:ffffc90000e9efa0 EFLAGS: 00000246
RAX: ffffc90000e9f1f0 RBX: ffffc90000e9f168 RCX: ffffc90000e9f201
RDX: ffffc90000e9f1f0 RSI: 1ffff920001d3e2e RDI: ffffc90000e9f1c0
RBP: ffffc90000e9f060 R08: ffffc90000e9f101 R09: 0000000000000000
R10: ffffc90000e9f168 R11: fffff520001d3e39 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffc90000e9f1a0 R15: 1ffff920001d3e35
FS:  00007fb0d47e8c80(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7671bf84c0 CR3: 000000010d35a000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000009951
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 unwind_next_frame+0x3c1/0x750 arch/x86/kernel/unwind_frame.c:315
 __unwind_start+0x34c/0x410 arch/x86/kernel/unwind_frame.c:417
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0xf2/0x170 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 save_stack+0x125/0x240 mm/page_owner.c:174
 __reset_page_owner+0x79/0x450 mm/page_owner.c:315
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1390 [inline]
 free_unref_page+0xbcf/0xf80 mm/page_alloc.c:2876
 __free_pages+0x6b/0x3b0 mm/page_alloc.c:5385
 __free_slab+0xb5/0x110 mm/slub.c:2758
 free_slab+0x18/0xe0 mm/slub.c:2781
 discard_slab mm/slub.c:2787 [inline]
 __put_partials+0x11b/0x150 mm/slub.c:3256
 put_cpu_partial+0x91/0xc0 mm/slub.c:3331
 __slab_free+0x1cf/0x2a0 mm/slub.c:4584
 do_slab_free mm/slub.c:4666 [inline]
 ___cache_free+0xc9/0xe0 mm/slub.c:4777
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0xb5/0x130 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x180 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x28/0x90 mm/kasan/common.c:331
 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]
 __do_kmalloc_node mm/slub.c:4394 [inline]
 __kmalloc_node_track_caller_noprof+0x1f9/0x4f0 mm/slub.c:4414
 kmalloc_reserve+0x144/0x4f0 net/core/skbuff.c:618
 __alloc_skb+0x144/0x370 net/core/skbuff.c:687
 alloc_skb include/linux/skbuff.h:1331 [inline]
 alloc_skb_with_frags+0xce/0x8b0 net/core/skbuff.c:6611
 sock_alloc_send_pskb+0x883/0x9a0 net/core/sock.c:2923
 unix_dgram_sendmsg+0x647/0x1ac0 net/unix/af_unix.c:2038
 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: 0033:0x7fb0d4938407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffd25e69d60 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fb0d47e8c80 RCX: 00007fb0d4938407
RDX: 000000000000004c RSI: 00007ffd25e69ea0 RDI: 0000000000000003
RBP: 00007ffd25e6a2d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffd25e6a2e8
R13: 00007ffd25e69ea0 R14: 0000000000000031 R15: 00007ffd25e69ea0
 </TASK>
net_ratelimit: 91245 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 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: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: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 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)
ip6_tunnel: syztnl0 xmit: Local address not yet configured!
net_ratelimit: 103979 callbacks suppressed
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 veth1_to_bridge with own address as source address (addr:4a:ea:31:cb:cb:44, 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:4a:ea:31:cb:cb:44, 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:4a:ea:31:cb:cb:44, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)