================================================================== 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+0x698/0x7e0 net/core/link_watch.c:245 Read of size 1 at addr ffff88807d908cc1 by task kworker/u8:6/1101 CPU: 1 UID: 0 PID: 1101 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound linkwatch_event Call Trace: dump_stack_lvl+0x189/0x250 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+0x698/0x7e0 net/core/link_watch.c:245 linkwatch_event+0x4c/0x60 net/core/link_watch.c:304 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 15046: 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:260 [inline] __do_kmalloc_node mm/slub.c:5366 [inline] __kvmalloc_node_noprof+0x5cd/0x910 mm/slub.c:6527 alloc_netdev_mqs+0xa6/0x11b0 net/core/dev.c:11861 rtnl_create_link+0x31f/0xd10 net/core/rtnetlink.c:3633 rtnl_newlink_create+0x25c/0xb00 net/core/rtnetlink.c:3815 __rtnl_newlink net/core/rtnetlink.c:3942 [inline] rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4057 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6946 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:729 __sys_sendto+0x3bd/0x520 net/socket.c:2231 __do_sys_sendto net/socket.c:2238 [inline] __se_sys_sendto net/socket.c:2234 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2234 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 12: 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:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2484 [inline] slab_free mm/slub.c:6121 [inline] kfree+0x199/0x6d0 mm/slub.c:6329 device_release+0x99/0x1c0 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+0x228/0x480 lib/kobject.c:737 netdev_run_todo+0xd2e/0xea0 net/core/dev.c:11562 ops_exit_rtnl_list net/core/net_namespace.c:188 [inline] ops_undo_list+0x3e1/0x990 net/core/net_namespace.c:247 cleanup_net+0x4c5/0x800 net/core/net_namespace.c:682 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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:559 insert_work+0x3d/0x330 kernel/workqueue.c:2186 __queue_work+0xcd2/0xfb0 kernel/workqueue.c:2341 queue_work_on+0x181/0x270 kernel/workqueue.c:2392 queue_work include/linux/workqueue.h:669 [inline] schedule_work include/linux/workqueue.h:730 [inline] __rhashtable_remove_fast_one include/linux/rhashtable.h:1069 [inline] __rhashtable_remove_fast include/linux/rhashtable.h:1093 [inline] rhashtable_remove_fast include/linux/rhashtable.h:1122 [inline] br_multicast_del_mdb_entry+0xc97/0xd20 net/bridge/br_multicast.c:642 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+0x1950/0x1ff0 net/core/dev.c:12236 ops_exit_rtnl_list net/core/net_namespace.c:186 [inline] ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:247 cleanup_net+0x4c5/0x800 net/core/net_namespace.c:682 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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:559 insert_work+0x3d/0x330 kernel/workqueue.c:2186 __queue_work+0xcd2/0xfb0 kernel/workqueue.c:2341 queue_work_on+0x181/0x270 kernel/workqueue.c:2392 queue_work include/linux/workqueue.h:669 [inline] br_multicast_del_mdb_entry+0xc18/0xd20 net/bridge/br_multicast.c:646 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+0x1950/0x1ff0 net/core/dev.c:12236 ops_exit_rtnl_list net/core/net_namespace.c:186 [inline] ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:247 cleanup_net+0x4c5/0x800 net/core/net_namespace.c:682 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff88807d908000 which belongs to the cache kmalloc-cg-8k of size 8192 The buggy address is located 3265 bytes inside of freed 8192-byte region [ffff88807d908000, ffff88807d90a000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7d908 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888051004581 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801a84b640 ffffea0001e6e800 0000000000000002 raw: 0000000000000000 0000000000020002 00000000f5000000 ffff888051004581 head: 00fff00000000040 ffff88801a84b640 ffffea0001e6e800 0000000000000002 head: 0000000000000000 0000000000020002 00000000f5000000 ffff888051004581 head: 00fff00000000003 ffffea0001f64201 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 14308, tgid 14304 (syz.0.2198), ts 771392736965, free_ts 750929192762 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3854 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5144 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2996 [inline] allocate_slab+0x8a/0x330 mm/slub.c:3164 new_slab mm/slub.c:3218 [inline] ___slab_alloc+0xbd1/0x13f0 mm/slub.c:4420 __slab_alloc+0x55/0xa0 mm/slub.c:4511 __slab_alloc_node mm/slub.c:4586 [inline] slab_alloc_node mm/slub.c:4996 [inline] __do_kmalloc_node mm/slub.c:5365 [inline] __kmalloc_node_track_caller_noprof+0x5c7/0x800 mm/slub.c:5385 __do_krealloc mm/slub.c:6406 [inline] krealloc_node_align_noprof+0x140/0x390 mm/slub.c:6465 copy_array+0x71/0x100 kernel/bpf/verifier.c:1392 copy_stack_state kernel/bpf/verifier.c:1452 [inline] copy_func_state kernel/bpf/verifier.c:1733 [inline] copy_verifier_state+0x958/0xf10 kernel/bpf/verifier.c:1778 push_stack+0x19d/0x390 kernel/bpf/verifier.c:2116 check_cond_jmp_op+0x1469/0x2910 kernel/bpf/verifier.c:16772 do_check_insn kernel/bpf/verifier.c:19967 [inline] do_check+0x675c/0xe520 kernel/bpf/verifier.c:20104 do_check_common+0x1949/0x24f0 kernel/bpf/verifier.c:23275 do_check_main kernel/bpf/verifier.c:23358 [inline] bpf_check+0x17474/0x1d2f0 kernel/bpf/verifier.c:24718 page last free pid 14059 tgid 14059 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2891 discard_slab mm/slub.c:3262 [inline] __put_partials+0x146/0x170 mm/slub.c:3727 put_cpu_partial+0x17c/0x250 mm/slub.c:3802 __slab_free+0x2b9/0x390 mm/slub.c:5555 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4710 [inline] slab_alloc_node mm/slub.c:5008 [inline] kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5015 getname_flags+0xb8/0x540 fs/namei.c:146 getname include/linux/fs.h:2919 [inline] __do_sys_symlinkat fs/namei.c:4780 [inline] __se_sys_symlinkat fs/namei.c:4777 [inline] __x64_sys_symlinkat+0x7a/0xb0 fs/namei.c:4777 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807d908b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d908c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807d908c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807d908d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d908d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================