================================================================== BUG: KASAN: slab-use-after-free in read_pnet include/net/net_namespace.h:414 [inline] BUG: KASAN: slab-use-after-free in dev_net include/linux/netdevice.h:2722 [inline] BUG: KASAN: slab-use-after-free in nf_hook_entry_head+0x1f1/0x2c0 net/netfilter/core.c:319 Read of size 8 at addr ffff88804a04c108 by task kworker/u8:8/4558 CPU: 1 UID: 0 PID: 4558 Comm: kworker/u8:8 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: netns cleanup_net 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 read_pnet include/net/net_namespace.h:414 [inline] dev_net include/linux/netdevice.h:2722 [inline] nf_hook_entry_head+0x1f1/0x2c0 net/netfilter/core.c:319 __nf_unregister_net_hook+0x74/0x700 net/netfilter/core.c:491 nft_unregister_flowtable_ops net/netfilter/nf_tables_api.c:8979 [inline] __nft_unregister_flowtable_net_hooks net/netfilter/nf_tables_api.c:8994 [inline] __nft_release_hook+0x180/0x350 net/netfilter/nf_tables_api.c:11987 __nft_release_hooks net/netfilter/nf_tables_api.c:12001 [inline] nf_tables_pre_exit_net+0xa7/0x110 net/netfilter/nf_tables_api.c:12152 ops_pre_exit_list net/core/net_namespace.c:161 [inline] ops_undo_list+0x187/0x990 net/core/net_namespace.c:234 cleanup_net+0x4d8/0x820 net/core/net_namespace.c:695 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+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 5186: 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:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5627 [inline] __kmalloc_node_track_caller_noprof+0x568/0x800 mm/slub.c:5736 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6671 sock_alloc_send_pskb+0x84d/0x980 net/core/sock.c:2965 unix_dgram_sendmsg+0x461/0x1850 net/unix/af_unix.c:2153 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 __sys_sendto+0x3bd/0x520 net/socket.c:2244 __do_sys_sendto net/socket.c:2251 [inline] __se_sys_sendto net/socket.c:2247 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2247 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 5179: 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+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2523 [inline] slab_free mm/slub.c:6611 [inline] kfree+0x19a/0x6d0 mm/slub.c:6818 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1087 skb_release_all net/core/skbuff.c:1152 [inline] __kfree_skb net/core/skbuff.c:1166 [inline] consume_skb+0x9e/0xf0 net/core/skbuff.c:1398 __unix_dgram_recvmsg+0x9f9/0xd60 net/unix/af_unix.c:2683 sock_recvmsg_nosec net/socket.c:1078 [inline] sock_recvmsg+0x22c/0x270 net/socket.c:1100 sock_read_iter+0x231/0x2f0 net/socket.c:1170 new_sync_read fs/read_write.c:491 [inline] vfs_read+0x55a/0xa30 fs/read_write.c:572 ksys_read+0x145/0x250 fs/read_write.c:715 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 The buggy address belongs to the object at ffff88804a04c000 which belongs to the cache kmalloc-cg-512 of size 512 The buggy address is located 264 bytes inside of freed 512-byte region [ffff88804a04c000, ffff88804a04c200) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4a04c head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888068bf5601 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813ffb0140 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000100010 00000000f5000000 ffff888068bf5601 head: 00fff00000000040 ffff88813ffb0140 dead000000000122 0000000000000000 head: 0000000000000000 0000000000100010 00000000f5000000 ffff888068bf5601 head: 00fff00000000002 ffffea0001281301 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5186, tgid 5186 (klogd), ts 760346397865, free_ts 759653352045 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+0x2365/0x2440 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3039 [inline] allocate_slab+0x96/0x3a0 mm/slub.c:3212 new_slab mm/slub.c:3266 [inline] ___slab_alloc+0xe94/0x18a0 mm/slub.c:4636 __slab_alloc+0x65/0x100 mm/slub.c:4755 __slab_alloc_node mm/slub.c:4831 [inline] slab_alloc_node mm/slub.c:5253 [inline] __do_kmalloc_node mm/slub.c:5626 [inline] __kmalloc_node_track_caller_noprof+0x5c7/0x800 mm/slub.c:5736 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6671 sock_alloc_send_pskb+0x84d/0x980 net/core/sock.c:2965 unix_dgram_sendmsg+0x461/0x1850 net/unix/af_unix.c:2153 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 __sys_sendto+0x3bd/0x520 net/socket.c:2244 __do_sys_sendto net/socket.c:2251 [inline] __se_sys_sendto net/socket.c:2247 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2247 page last free pid 21144 tgid 21144 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:2906 free_large_kmalloc+0x13a/0x1f0 mm/slub.c:6744 device_release+0x9c/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+0x22b/0x480 lib/kobject.c:737 netdev_run_todo+0xd2e/0xea0 net/core/dev.c:11601 tun_detach drivers/net/tun.c:640 [inline] tun_chr_close+0x13c/0x1c0 drivers/net/tun.c:3436 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:966 __do_sys_exit kernel/exit.c:1074 [inline] __se_sys_exit kernel/exit.c:1072 [inline] __pfx___ia32_sys_exit+0x0/0x10 kernel/exit.c:1072 x64_sys_call+0x21da/0x2200 arch/x86/include/generated/asm/syscalls_64.h:61 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: ffff88804a04c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804a04c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88804a04c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804a04c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804a04c200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================