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BUG: KASAN: use-after-free in read_pnet include/net/net_namespace.h:419 [inline]
BUG: KASAN: use-after-free in dev_net include/linux/netdevice.h:2741 [inline]
BUG: KASAN: use-after-free in nf_hook_entry_head+0x1f1/0x2c0 net/netfilter/core.c:319
Read of size 8 at addr ffff88807c394108 by task kworker/u8:18/15700

CPU: 0 UID: 0 PID: 15700 Comm: kworker/u8:18 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 read_pnet include/net/net_namespace.h:419 [inline]
 dev_net include/linux/netdevice.h:2741 [inline]
 nf_hook_entry_head+0x1f1/0x2c0 net/netfilter/core.c:319
 __nf_unregister_net_hook+0x74/0x6f0 net/netfilter/core.c:491
 nft_unregister_flowtable_ops net/netfilter/nf_tables_api.c:8895 [inline]
 __nft_unregister_flowtable_net_hooks net/netfilter/nf_tables_api.c:8910 [inline]
 __nft_release_hook net/netfilter/nf_tables_api.c:11899 [inline]
 __nft_release_hooks net/netfilter/nf_tables_api.c:11913 [inline]
 nf_tables_pre_exit_net+0x64a/0x900 net/netfilter/nf_tables_api.c:12064
 ops_pre_exit_list net/core/net_namespace.c:161 [inline]
 ops_undo_list+0x187/0x940 net/core/net_namespace.c:234
 cleanup_net+0x56b/0x800 net/core/net_namespace.c:704
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807c397740 pfn:0x7c394
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f0(buddy)
raw: 00fff00000000000 ffffea000225b008 ffffea0001e57308 0000000000000000
raw: ffff88807c397740 0000000000000002 00000000f0000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 22574, tgid 22573 (syz.1.4005), ts 1510743769306, free_ts 1520937779854
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3269 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3458
 new_slab mm/slub.c:3516 [inline]
 refill_objects+0x331/0x3c0 mm/slub.c:7153
 refill_sheaf mm/slub.c:2818 [inline]
 __pcs_replace_empty_main+0x2b9/0x620 mm/slub.c:4592
 alloc_from_pcs mm/slub.c:4695 [inline]
 slab_alloc_node mm/slub.c:4829 [inline]
 kmem_cache_alloc_node_noprof+0x441/0x690 mm/slub.c:4896
 kmalloc_reserve net/core/skbuff.c:613 [inline]
 __alloc_skb+0x27d/0x7d0 net/core/skbuff.c:713
 alloc_skb include/linux/skbuff.h:1383 [inline]
 alloc_uevent_skb+0x7d/0x230 lib/kobject_uevent.c:289
 uevent_net_broadcast_tagged lib/kobject_uevent.c:352 [inline]
 kobject_uevent_net_broadcast+0x184/0x560 lib/kobject_uevent.c:413
 kobject_uevent_env+0x55c/0x9e0 lib/kobject_uevent.c:608
 rx_queue_add_kobject net/core/net-sysfs.c:1280 [inline]
 net_rx_queue_update_kobjects+0x3e5/0x740 net/core/net-sysfs.c:1322
 register_queue_kobjects net/core/net-sysfs.c:2114 [inline]
 netdev_register_kobject+0x21f/0x310 net/core/net-sysfs.c:2362
 register_netdevice+0x12c0/0x1cf0 net/core/dev.c:11422
 veth_newlink+0x4a4/0xb70 drivers/net/veth.c:1860
 rtnl_newlink_create+0x329/0xb70 net/core/rtnetlink.c:3840
page last free pid 18197 tgid 18197 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978
 __slab_free+0x263/0x2b0 mm/slub.c:5551
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:406
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_node_noprof+0x3ef/0x6b0 mm/slub.c:5370
 kmalloc_node_noprof include/linux/slab.h:1077 [inline]
 __get_vm_area_node+0x13f/0x300 mm/vmalloc.c:3221
 __vmalloc_node_range_noprof+0x372/0x1730 mm/vmalloc.c:4024
 __vmalloc_node_noprof mm/vmalloc.c:4124 [inline]
 vzalloc_noprof+0xb2/0xe0 mm/vmalloc.c:4202
 alloc_counters+0x64/0x5d0 net/ipv4/netfilter/ip_tables.c:799
 copy_entries_to_user net/ipv6/netfilter/ip6_tables.c:837 [inline]
 get_entries net/ipv6/netfilter/ip6_tables.c:1039 [inline]
 do_ip6t_get_ctl+0xabd/0x1230 net/ipv6/netfilter/ip6_tables.c:1677
 nf_getsockopt+0x26e/0x290 net/netfilter/nf_sockopt.c:116
 ipv6_getsockopt+0x1fd/0x2b0 net/ipv6/ipv6_sockglue.c:1473
 do_sock_getsockopt+0x2d3/0x3f0 net/socket.c:2383
 __sys_getsockopt net/socket.c:2412 [inline]
 __do_sys_getsockopt net/socket.c:2419 [inline]
 __se_sys_getsockopt net/socket.c:2416 [inline]
 __x64_sys_getsockopt+0x1a4/0x240 net/socket.c:2416
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94

Memory state around the buggy address:
 ffff88807c394000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807c394080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88807c394100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                      ^
 ffff88807c394180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807c394200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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