================================================================== BUG: KASAN: slab-use-after-free in netdev_need_ops_lock include/net/netdev_lock.h:30 [inline] BUG: KASAN: slab-use-after-free in netdev_unlock_ops include/net/netdev_lock.h:47 [inline] BUG: KASAN: slab-use-after-free in __linkwatch_run_queue+0x5b6/0x7e0 net/core/link_watch.c:245 Read of size 8 at addr ffff888032e8cb88 by task kworker/u8:7/1094 CPU: 0 UID: 0 PID: 1094 Comm: kworker/u8:7 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound linkwatch_event Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 netdev_need_ops_lock include/net/netdev_lock.h:30 [inline] netdev_unlock_ops include/net/netdev_lock.h:47 [inline] __linkwatch_run_queue+0x5b6/0x7e0 net/core/link_watch.c:245 linkwatch_event+0x4c/0x60 net/core/link_watch.c:304 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 5846: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5657 [inline] __kvmalloc_node_noprof+0x5d5/0x920 mm/slub.c:7136 alloc_netdev_mqs+0xa6/0x11b0 net/core/dev.c:11997 rtnl_create_link+0x31f/0xcf0 net/core/rtnetlink.c:3648 rtnl_newlink_create+0x25c/0xb00 net/core/rtnetlink.c:3830 __rtnl_newlink net/core/rtnetlink.c:3957 [inline] rtnl_newlink+0x16e7/0x1c90 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 __sys_sendto+0x3bd/0x520 net/socket.c:2206 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2209 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8280: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x1c0/0x660 mm/slub.c:6878 device_release+0x9e/0x1d0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x228/0x570 lib/kobject.c:737 netdev_run_todo+0xd2c/0xea0 net/core/dev.c:11698 ops_exit_rtnl_list net/core/net_namespace.c:189 [inline] ops_undo_list+0x3e1/0x990 net/core/net_namespace.c:248 cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 insert_work+0x3d/0x330 kernel/workqueue.c:2180 __queue_work+0xcd0/0xf90 kernel/workqueue.c:2335 queue_work_on+0x106/0x1c0 kernel/workqueue.c:2386 br_multicast_dev_del+0xea/0x340 net/bridge/br_multicast.c:4460 br_dev_uninit+0x1c/0x40 net/bridge/br_device.c:157 unregister_netdevice_many_notify+0x1ce5/0x2340 net/core/dev.c:12402 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline] ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:248 cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Second to last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 insert_work+0x3d/0x330 kernel/workqueue.c:2180 __queue_work+0xcd0/0xf90 kernel/workqueue.c:2335 queue_work_on+0x106/0x1c0 kernel/workqueue.c:2386 queue_work include/linux/workqueue.h:669 [inline] schedule_work include/linux/workqueue.h:730 [inline] __rhashtable_remove_fast_one include/linux/rhashtable.h:1115 [inline] __rhashtable_remove_fast include/linux/rhashtable.h:1139 [inline] rhashtable_remove_fast include/linux/rhashtable.h:1168 [inline] fdb_delete+0xdb3/0xf60 net/bridge/br_fdb.c:320 br_fdb_delete_by_port+0x24a/0x310 net/bridge/br_fdb.c:882 del_nbp+0x589/0xa60 net/bridge/br_if.c:357 br_dev_delete+0x6e/0x110 net/bridge/br_if.c:386 br_net_exit_rtnl+0xb1/0x120 net/bridge/br.c:414 ops_exit_rtnl_list net/core/net_namespace.c:181 [inline] ops_undo_list+0x350/0x990 net/core/net_namespace.c:248 cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 The buggy address belongs to the object at ffff888032e8c000 which belongs to the cache kmalloc-cg-8k of size 8192 The buggy address is located 2952 bytes inside of freed 8192-byte region [ffff888032e8c000, ffff888032e8e000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x32e88 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813ffb0640 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813ffb0640 dead000000000122 0000000000000000 head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000cba201 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5845, tgid 5845 (syz-executor), ts 84733456828, free_ts 82796528235 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0x24e0/0x2580 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xe53/0x1820 mm/slub.c:4656 __slab_alloc+0x65/0x100 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x47d/0x800 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] __register_sysctl_table+0x72/0x1340 fs/proc/proc_sysctl.c:1379 ipv4_sysctl_init_net+0x1fd/0x3b0 net/ipv4/sysctl_net_ipv4.c:1674 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137 setup_net+0x110/0x330 net/core/net_namespace.c:446 copy_net_ns+0x3e3/0x570 net/core/net_namespace.c:581 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:130 unshare_nsproxy_namespaces+0x11c/0x170 kernel/nsproxy.c:226 ksys_unshare+0x4c8/0x8c0 kernel/fork.c:3171 page last free pid 5819 tgid 5819 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943 __folio_put+0x21b/0x2c0 mm/swap.c:112 put_netmem net/core/skbuff.c:7417 [inline] skb_page_unref include/linux/skbuff_ref.h:43 [inline] __skb_frag_unref include/linux/skbuff_ref.h:56 [inline] skb_release_data+0x49a/0x7c0 net/core/skbuff.c:1101 skb_release_all net/core/skbuff.c:1182 [inline] __kfree_skb+0x55/0x70 net/core/skbuff.c:1196 tcp_clean_rtx_queue net/ipv4/tcp_input.c:3494 [inline] tcp_ack+0x2341/0x6a30 net/ipv4/tcp_input.c:4119 tcp_rcv_established+0x13de/0x2580 net/ipv4/tcp_input.c:6374 tcp_v4_do_rcv+0xa90/0x1430 net/ipv4/tcp_ipv4.c:1881 sk_backlog_rcv include/net/sock.h:1177 [inline] __release_sock+0x265/0x3a0 net/core/sock.c:3213 release_sock+0x5f/0x1f0 net/core/sock.c:3795 tcp_sendmsg+0x39/0x50 net/ipv4/tcp.c:1413 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x19c/0x270 net/socket.c:742 sock_write_iter+0x279/0x360 net/socket.c:1195 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888032e8ca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888032e8cb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888032e8cb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888032e8cc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888032e8cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================