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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 ffff888024e40108 by task kworker/u8:20/15678

CPU: 1 UID: 0 PID: 15678 Comm: kworker/u8:20 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:0xffff888024e42000 pfn:0x24e40
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f0(buddy)
raw: 00fff00000000000 ffffea0001337c08 ffffea0001aec108 0000000000000000
raw: ffff888024e42000 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 5486, tgid 5486 (dhcpcd), ts 1218603255627, free_ts 1232697689225
 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:3255 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3444
 new_slab mm/slub.c:3502 [inline]
 refill_objects+0x331/0x3c0 mm/slub.c:7134
 refill_sheaf mm/slub.c:2804 [inline]
 __pcs_replace_empty_main+0x2b9/0x620 mm/slub.c:4578
 alloc_from_pcs mm/slub.c:4681 [inline]
 slab_alloc_node mm/slub.c:4815 [inline]
 __do_kmalloc_node mm/slub.c:5218 [inline]
 __kmalloc_node_track_caller_noprof+0x572/0x7b0 mm/slub.c:5327
 kmalloc_reserve net/core/skbuff.c:635 [inline]
 __alloc_skb+0x2c1/0x7d0 net/core/skbuff.c:713
 alloc_skb include/linux/skbuff.h:1383 [inline]
 alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6750
 sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:2995
 unix_dgram_sendmsg+0x460/0x18e0 net/unix/af_unix.c:2125
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 sock_write_iter+0x503/0x550 net/socket.c:1195
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x61d/0xb90 fs/read_write.c:688
 ksys_write+0x150/0x270 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5486 tgid 5486 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:5532
 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_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4501 [inline]
 slab_alloc_node mm/slub.c:4830 [inline]
 kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4882
 __alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702
 alloc_skb include/linux/skbuff.h:1383 [inline]
 alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6750
 sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:2995
 unix_dgram_sendmsg+0x460/0x18e0 net/unix/af_unix.c:2125
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 sock_write_iter+0x503/0x550 net/socket.c:1195
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x61d/0xb90 fs/read_write.c:688
 ksys_write+0x150/0x270 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888024e40000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888024e40080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888024e40100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                      ^
 ffff888024e40180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888024e40200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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