==================================================================
BUG: KASAN: use-after-free in __write_once_size include/linux/compiler.h:295 [inline]
BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:789 [inline]
BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:824 [inline]
BUG: KASAN: use-after-free in detach_if_pending+0x160/0x360 kernel/time/timer.c:841
Write of size 8 at addr ffff8881e91eb1c0 by task kworker/u4:4/611

CPU: 1 PID: 611 Comm: kworker/u4:4 Not tainted 5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d8/0x241 lib/dump_stack.c:118
 print_address_description+0x8c/0x600 mm/kasan/report.c:384
 __kasan_report+0xf3/0x120 mm/kasan/report.c:516
 kasan_report+0x30/0x60 mm/kasan/common.c:653
 __write_once_size include/linux/compiler.h:295 [inline]
 __hlist_del include/linux/list.h:789 [inline]
 detach_timer kernel/time/timer.c:824 [inline]
 detach_if_pending+0x160/0x360 kernel/time/timer.c:841
 del_timer+0xcf/0x140 kernel/time/timer.c:1232
 addrconf_del_rs_timer net/ipv6/addrconf.c:305 [inline]
 addrconf_ifdown+0x640/0x1a90 net/ipv6/addrconf.c:3834
 addrconf_notify+0x375/0xe50 net/ipv6/addrconf.c:3698
 notifier_call_chain kernel/notifier.c:98 [inline]
 __raw_notifier_call_chain kernel/notifier.c:399 [inline]
 raw_notifier_call_chain+0x95/0x110 kernel/notifier.c:406
 call_netdevice_notifiers_info net/core/dev.c:1670 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:1682 [inline]
 call_netdevice_notifiers net/core/dev.c:1696 [inline]
 dev_close_many+0x354/0x4f0 net/core/dev.c:1439
 rollback_registered_many+0x493/0x1330 net/core/dev.c:8627
 unregister_netdevice_many+0x46/0x250 net/core/dev.c:9805
 ip_tunnel_delete_nets+0x33b/0x380 net/ipv4/ip_tunnel.c:1129
 ops_exit_list net/core/net_namespace.c:187 [inline]
 cleanup_net+0x6e2/0xc90 net/core/net_namespace.c:612
 process_one_work+0x765/0xd20 kernel/workqueue.c:2290
 worker_thread+0xaef/0x1470 kernel/workqueue.c:2436
 kthread+0x2da/0x360 kernel/kthread.c:288
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354

Allocated by task 4353:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 __kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc_node mm/slub.c:2829 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 __kmalloc_track_caller+0x100/0x2b0 mm/slub.c:4449
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 pskb_expand_head+0x10c/0x10b0 net/core/skbuff.c:1653
 netlink_trim+0x198/0x230 net/netlink/af_netlink.c:1288
 netlink_broadcast_filtered+0x62/0x1280 net/netlink/af_netlink.c:1493
 netlink_broadcast net/netlink/af_netlink.c:1538 [inline]
 nlmsg_multicast include/net/netlink.h:968 [inline]
 nlmsg_notify+0xf7/0x1b0 net/netlink/af_netlink.c:2510
 __dev_notify_flags+0xe3/0x510 net/core/dev.c:7992
 rtnl_configure_link+0x21e/0x320 net/core/rtnetlink.c:2937
 veth_newlink+0x6ef/0xb50 drivers/net/veth.c:1310
 __rtnl_newlink net/core/rtnetlink.c:3255 [inline]
 rtnl_newlink+0x1567/0x2060 net/core/rtnetlink.c:3314
 rtnetlink_rcv_msg+0x983/0xc70 net/core/rtnetlink.c:5290
 netlink_rcv_skb+0x1d5/0x420 net/netlink/af_netlink.c:2467
 netlink_unicast_kernel net/netlink/af_netlink.c:1306 [inline]
 netlink_unicast+0x936/0xb20 net/netlink/af_netlink.c:1332
 netlink_sendmsg+0xa18/0xcf0 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:638 [inline]
 __sock_sendmsg net/socket.c:650 [inline]
 __sys_sendto+0x4f3/0x6c0 net/socket.c:1961
 __do_sys_sendto net/socket.c:1973 [inline]
 __se_sys_sendto net/socket.c:1969 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:1969
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Freed by task 4353:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 kasan_set_free_info mm/kasan/common.c:345 [inline]
 __kasan_slab_free+0x1b5/0x270 mm/kasan/common.c:487
 slab_free_hook mm/slub.c:1455 [inline]
 slab_free_freelist_hook mm/slub.c:1494 [inline]
 slab_free mm/slub.c:3080 [inline]
 kfree+0x123/0x370 mm/slub.c:4071
 skb_release_all net/core/skbuff.c:675 [inline]
 __kfree_skb net/core/skbuff.c:689 [inline]
 consume_skb+0xa5/0x2a0 net/core/skbuff.c:849
 netlink_broadcast_filtered+0x115f/0x1280 net/netlink/af_netlink.c:1516
 netlink_broadcast net/netlink/af_netlink.c:1538 [inline]
 nlmsg_multicast include/net/netlink.h:968 [inline]
 nlmsg_notify+0xf7/0x1b0 net/netlink/af_netlink.c:2510
 __dev_notify_flags+0xe3/0x510 net/core/dev.c:7992
 rtnl_configure_link+0x21e/0x320 net/core/rtnetlink.c:2937
 veth_newlink+0x6ef/0xb50 drivers/net/veth.c:1310
 __rtnl_newlink net/core/rtnetlink.c:3255 [inline]
 rtnl_newlink+0x1567/0x2060 net/core/rtnetlink.c:3314
 rtnetlink_rcv_msg+0x983/0xc70 net/core/rtnetlink.c:5290
 netlink_rcv_skb+0x1d5/0x420 net/netlink/af_netlink.c:2467
 netlink_unicast_kernel net/netlink/af_netlink.c:1306 [inline]
 netlink_unicast+0x936/0xb20 net/netlink/af_netlink.c:1332
 netlink_sendmsg+0xa18/0xcf0 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:638 [inline]
 __sock_sendmsg net/socket.c:650 [inline]
 __sys_sendto+0x4f3/0x6c0 net/socket.c:1961
 __do_sys_sendto net/socket.c:1973 [inline]
 __se_sys_sendto net/socket.c:1969 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:1969
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

The buggy address belongs to the object at ffff8881e91eb000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 448 bytes inside of
 2048-byte region [ffff8881e91eb000, ffff8881e91eb800)
The buggy address belongs to the page:
page:ffffea0007a47a00 refcount:1 mapcount:0 mapping:ffff8881f5c0c000 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5c0c000
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x18f/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4893
 alloc_slab_page+0x39/0x3c0 mm/slub.c:343
 allocate_slab mm/slub.c:1683 [inline]
 new_slab+0x97/0x440 mm/slub.c:1749
 new_slab_objects mm/slub.c:2505 [inline]
 ___slab_alloc+0x2fe/0x490 mm/slub.c:2667
 __slab_alloc+0x62/0xa0 mm/slub.c:2707
 slab_alloc_node mm/slub.c:2792 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 __kmalloc_track_caller+0x16d/0x2b0 mm/slub.c:4449
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0xb4/0x4d0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1080 [inline]
 nlmsg_new include/net/netlink.h:888 [inline]
 inet6_ifinfo_notify+0x69/0x110 net/ipv6/addrconf.c:5975
 addrconf_notify+0xb3b/0xe50 net/ipv6/addrconf.c:3682
 notifier_call_chain kernel/notifier.c:98 [inline]
 __raw_notifier_call_chain kernel/notifier.c:399 [inline]
 raw_notifier_call_chain+0x95/0x110 kernel/notifier.c:406
 __dev_notify_flags+0x26e/0x510 net/core/dev.c:1670
 rtnl_configure_link net/core/rtnetlink.c:2937 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3274 [inline]
 rtnl_newlink+0x1a38/0x2060 net/core/rtnetlink.c:3314
 rtnetlink_rcv_msg+0x983/0xc70 net/core/rtnetlink.c:5290
 netlink_rcv_skb+0x1d5/0x420 net/netlink/af_netlink.c:2467
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1176 [inline]
 __free_pages_ok+0x847/0x950 mm/page_alloc.c:1438
 free_the_page mm/page_alloc.c:4955 [inline]
 __free_pages+0x91/0x140 mm/page_alloc.c:4961
 device_release+0x6b/0x190 drivers/base/core.c:1776
 kobject_cleanup lib/kobject.c:716 [inline]
 kobject_release lib/kobject.c:747 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1e6/0x2f0 lib/kobject.c:764
 netdev_run_todo+0xc44/0xdf0 net/core/dev.c:9488
 tun_detach drivers/net/tun.c:766 [inline]
 tun_chr_close+0xc1/0x130 drivers/net/tun.c:3563
 __fput+0x262/0x680 fs/file_table.c:281
 task_work_run+0x140/0x170 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xcaf/0x2bc0 kernel/exit.c:861
 do_group_exit+0x138/0x300 kernel/exit.c:984
 __do_sys_exit_group kernel/exit.c:995 [inline]
 __se_sys_exit_group kernel/exit.c:993 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:993
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Memory state around the buggy address:
 ffff8881e91eb080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881e91eb100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881e91eb180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff8881e91eb200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881e91eb280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
device bridge_slave_1 left promiscuous mode
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_0 left promiscuous mode
bridge0: port 1(bridge_slave_0) entered disabled state
device bridge_slave_1 left promiscuous mode
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_0 left promiscuous mode
bridge0: port 1(bridge_slave_0) entered disabled state
device bridge_slave_1 left promiscuous mode
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_0 left promiscuous mode
bridge0: port 1(bridge_slave_0) entered disabled state