================================================================== 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:2725 [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 ffff888055d98108 by task kworker/u8:5/194 CPU: 0 UID: 0 PID: 194 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:2725 [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:8977 [inline] __nft_unregister_flowtable_net_hooks net/netfilter/nf_tables_api.c:8992 [inline] __nft_release_hook+0x180/0x350 net/netfilter/nf_tables_api.c:11985 __nft_release_hooks net/netfilter/nf_tables_api.c:11999 [inline] nf_tables_pre_exit_net+0xa7/0x110 net/netfilter/nf_tables_api.c:12150 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:696 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 8205: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4978 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5340 kmalloc_reserve+0xbd/0x290 net/core/skbuff.c:583 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:674 alloc_skb include/linux/skbuff.h:1383 [inline] nlmsg_new include/net/netlink.h:1055 [inline] netlink_ack+0x146/0xa50 net/netlink/af_netlink.c:2487 netlink_rcv_skb+0x28c/0x470 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 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 8205: 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:2543 [inline] slab_free mm/slub.c:6638 [inline] kmem_cache_free+0x19b/0x690 mm/slub.c:6748 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1091 skb_release_all net/core/skbuff.c:1166 [inline] __kfree_skb net/core/skbuff.c:1180 [inline] consume_skb+0x9e/0xf0 net/core/skbuff.c:1412 netlink_recvmsg+0x5b2/0xa30 net/netlink/af_netlink.c:1972 sock_recvmsg_nosec net/socket.c:1078 [inline] sock_recvmsg+0x22c/0x270 net/socket.c:1100 __sys_recvfrom+0x1f6/0x340 net/socket.c:2294 __do_sys_recvfrom net/socket.c:2309 [inline] __se_sys_recvfrom net/socket.c:2305 [inline] __x64_sys_recvfrom+0xde/0x100 net/socket.c:2305 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 ffff888055d98000 which belongs to the cache skbuff_small_head of size 704 The buggy address is located 264 bytes inside of freed 704-byte region [ffff888055d98000, ffff888055d982c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x55d98 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801e2bdb40 ffffea00016a4500 dead000000000004 raw: 0000000000000000 0000000000130013 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801e2bdb40 ffffea00016a4500 dead000000000004 head: 0000000000000000 0000000000130013 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0001576601 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 7889, tgid 7887 (syz.1.501), ts 170086705939, free_ts 168636632220 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:3059 [inline] allocate_slab+0x96/0x350 mm/slub.c:3232 new_slab mm/slub.c:3286 [inline] ___slab_alloc+0xf56/0x1990 mm/slub.c:4655 __slab_alloc+0x65/0x100 mm/slub.c:4778 __slab_alloc_node mm/slub.c:4854 [inline] slab_alloc_node mm/slub.c:5276 [inline] kmem_cache_alloc_node_noprof+0x4c5/0x710 mm/slub.c:5340 kmalloc_reserve+0xbd/0x290 net/core/skbuff.c:583 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:674 alloc_skb include/linux/skbuff.h:1383 [inline] nlmsg_new include/net/netlink.h:1055 [inline] inet6_netconf_notify_devconf+0x10f/0x1d0 net/ipv6/addrconf.c:593 __addrconf_sysctl_unregister net/ipv6/addrconf.c:7357 [inline] addrconf_sysctl_unregister net/ipv6/addrconf.c:7381 [inline] addrconf_ifdown+0x1543/0x1880 net/ipv6/addrconf.c:4006 addrconf_notify+0x1bc/0x1010 net/ipv6/addrconf.c:-1 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] unregister_netdevice_many_notify+0x1860/0x2390 net/core/dev.c:12373 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline] ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:248 page last free pid 7870 tgid 7865 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 stack_depot_save_flags+0x436/0x860 lib/stackdepot.c:727 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x4f/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] __kmalloc_cache_noprof+0x3d5/0x6f0 mm/slub.c:5771 kmalloc_noprof include/linux/slab.h:957 [inline] call_modprobe kernel/module/kmod.c:83 [inline] __request_module+0x2b5/0x5e0 kernel/module/kmod.c:172 inet_create+0x3a8/0x1000 net/ipv4/af_inet.c:308 __sock_create+0x4b3/0x9f0 net/socket.c:1605 sock_create net/socket.c:1663 [inline] __sys_socket_create net/socket.c:1700 [inline] __sys_socket+0xd7/0x1b0 net/socket.c:1747 __do_sys_socket net/socket.c:1761 [inline] __se_sys_socket net/socket.c:1759 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1759 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: ffff888055d98000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888055d98080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888055d98100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888055d98180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888055d98200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================