==================================================================
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 ffff88806d240108 by task kworker/u8:1/13

CPU: 1 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full) 
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:467
 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:0xffff88806d242a40 pfn:0x6d240
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea000153b908 ffffea0001530608 0000000000000000
raw: ffff88806d242a40 0000000000000000 00000000ffffffff 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 0x92cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_NOMEMALLOC), pid 6095, tgid 6093 (syz.4.26), ts 98210902209, free_ts 98210958438
 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_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2484
 alloc_frozen_pages_noprof mm/mempolicy.c:2555 [inline]
 alloc_pages_noprof+0xa8/0x190 mm/mempolicy.c:2575
 stack_depot_save_flags+0x73c/0x810 lib/stackdepot.c:685
 kasan_save_stack mm/kasan/common.c:58 [inline]
 kasan_save_track+0x4f/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5219 [inline]
 __kmalloc_node_noprof+0x4e0/0x7c0 mm/slub.c:5225
 kmalloc_node_noprof include/linux/slab.h:1093 [inline]
 alloc_slab_obj_exts+0x4b/0x1b0 mm/slub.c:2174
 __memcg_slab_post_alloc_hook+0x53c/0xa80 mm/memcontrol.c:3234
 memcg_slab_post_alloc_hook mm/slub.c:2459 [inline]
 slab_post_alloc_hook mm/slub.c:4512 [inline]
 slab_alloc_node mm/slub.c:4830 [inline]
 __do_kmalloc_node mm/slub.c:5218 [inline]
 __kmalloc_node_track_caller_noprof+0x539/0x7b0 mm/slub.c:5327
 kmemdup_noprof+0x2b/0x70 mm/util.c:138
 kmemdup_noprof include/linux/fortify-string.h:763 [inline]
 neigh_sysctl_register+0xae/0xa90 net/core/neighbour.c:3861
 devinet_sysctl_register+0xad/0x200 net/ipv4/devinet.c:2714
 inetdev_init+0x2a4/0x4e0 net/ipv4/devinet.c:291
page last free pid 6095 tgid 6093 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
 stack_depot_save_flags+0x40e/0x810 lib/stackdepot.c:735
 kasan_save_stack mm/kasan/common.c:58 [inline]
 kasan_save_track+0x4f/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5219 [inline]
 __kmalloc_node_noprof+0x4e0/0x7c0 mm/slub.c:5225
 kmalloc_node_noprof include/linux/slab.h:1093 [inline]
 alloc_slab_obj_exts+0x4b/0x1b0 mm/slub.c:2174
 __memcg_slab_post_alloc_hook+0x53c/0xa80 mm/memcontrol.c:3234
 memcg_slab_post_alloc_hook mm/slub.c:2459 [inline]
 slab_post_alloc_hook mm/slub.c:4512 [inline]
 slab_alloc_node mm/slub.c:4830 [inline]
 __do_kmalloc_node mm/slub.c:5218 [inline]
 __kmalloc_node_track_caller_noprof+0x539/0x7b0 mm/slub.c:5327
 kmemdup_noprof+0x2b/0x70 mm/util.c:138
 kmemdup_noprof include/linux/fortify-string.h:763 [inline]
 neigh_sysctl_register+0xae/0xa90 net/core/neighbour.c:3861
 devinet_sysctl_register+0xad/0x200 net/ipv4/devinet.c:2714
 inetdev_init+0x2a4/0x4e0 net/ipv4/devinet.c:291
 inetdev_event+0x30d/0x1610 net/ipv4/devinet.c:1590
 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 register_netdevice+0x173a/0x1cf0 net/core/dev.c:11449
 tun_set_iff+0x844/0xf00 drivers/net/tun.c:2807

Memory state around the buggy address:
 ffff88806d240000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806d240080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88806d240100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                      ^
 ffff88806d240180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806d240200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================