netlink: 'syz.2.7437': attribute type 4 has an invalid length. ================================================================== BUG: KASAN: slab-use-after-free in read_pnet include/net/net_namespace.h:419 [inline] BUG: KASAN: slab-use-after-free in dev_net include/linux/netdevice.h:2741 [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 ffff88806665c108 by task syz.2.7437/28344 CPU: 0 UID: 0 PID: 28344 Comm: syz.2.7437 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 Call Trace: 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:8905 [inline] __nft_unregister_flowtable_net_hooks net/netfilter/nf_tables_api.c:8920 [inline] nft_unregister_flowtable_net_hooks net/netfilter/nf_tables_api.c:8932 [inline] nf_tables_commit+0x4270/0xa400 net/netfilter/nf_tables_api.c:11086 nfnetlink_rcv_batch net/netfilter/nfnetlink.c:576 [inline] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:649 [inline] nfnetlink_rcv+0x1c1b/0x27b0 net/netfilter/nfnetlink.c:667 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 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 RIP: 0033:0x7f8cec59c799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8ced3c8028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f8cec815fa0 RCX: 00007f8cec59c799 RDX: 0000000000000000 RSI: 000020000000c2c0 RDI: 000000000000000d RBP: 00007f8cec632c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8cec816038 R14: 00007f8cec815fa0 R15: 00007ffd35af9528 Allocated by task 14759: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/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] __kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5383 kmalloc_noprof include/linux/slab.h:950 [inline] tipc_sub_subscribe+0x118/0x690 net/tipc/subscr.c:146 tipc_conn_rcv_sub+0x136/0x350 net/tipc/topsrv.c:378 tipc_conn_rcv_from_sock net/tipc/topsrv.c:408 [inline] tipc_conn_recv_work+0x373/0x500 net/tipc/topsrv.c:424 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 Freed by task 14759: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2692 [inline] slab_free mm/slub.c:6168 [inline] kfree+0x1c1/0x630 mm/slub.c:6486 tipc_conn_delete_sub+0x163/0x190 net/tipc/topsrv.c:240 tipc_conn_send_to_sock net/tipc/topsrv.c:268 [inline] tipc_conn_send_work+0x267/0xa30 net/tipc/topsrv.c:306 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 The buggy address belongs to the object at ffff88806665c000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 264 bytes inside of freed 512-byte region [ffff88806665c000, ffff88806665c200) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88806665cc00 pfn:0x6665c head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88813fea8c80 ffffea00016c7710 ffffea00006ea610 raw: ffff88806665cc00 000000080010000d 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88813fea8c80 ffffea00016c7710 ffffea00006ea610 head: ffff88806665cc00 000000080010000d 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0001999701 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 7309, tgid 7309 (kworker/u8:18), ts 1014291836605, free_ts 1014102892517 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:3296 [inline] allocate_slab+0x77/0x660 mm/slub.c:3485 new_slab mm/slub.c:3543 [inline] refill_objects+0x331/0x3c0 mm/slub.c:7178 __pcs_replace_empty_main+0x2f9/0x5e0 mm/slub.c:-1 alloc_from_pcs mm/slub.c:4720 [inline] slab_alloc_node mm/slub.c:4854 [inline] __kmalloc_cache_noprof+0x392/0x660 mm/slub.c:5378 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] mld_add_delrec net/ipv6/mcast.c:743 [inline] igmp6_leave_group net/ipv6/mcast.c:2667 [inline] igmp6_group_dropped+0x740/0x1140 net/ipv6/mcast.c:724 __ipv6_dev_mc_dec+0x2a8/0x330 net/ipv6/mcast.c:1001 addrconf_leave_solict net/ipv6/addrconf.c:2256 [inline] __ipv6_ifa_notify+0x77c/0xc60 net/ipv6/addrconf.c:6303 addrconf_ifdown+0xea6/0x1a40 net/ipv6/addrconf.c:3981 addrconf_notify+0x1bc/0x1050 net/ipv6/addrconf.c:-1 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] netif_close_many+0x2ae/0x420 net/core/dev.c:1804 unregister_netdevice_many_notify+0xb47/0x2370 net/core/dev.c:12384 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline] ops_undo_list+0x3d3/0x940 net/core/net_namespace.c:248 page last free pid 5487 tgid 5487 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 skb_kfree_head net/core/skbuff.c:1089 [inline] skb_free_head net/core/skbuff.c:1101 [inline] skb_release_data+0x6f0/0x940 net/core/skbuff.c:1128 skb_release_all net/core/skbuff.c:1203 [inline] __kfree_skb+0x5d/0x210 net/core/skbuff.c:1217 netlink_recvmsg+0x5d6/0xa50 net/netlink/af_netlink.c:1972 sock_recvmsg_nosec net/socket.c:1078 [inline] sock_recvmsg+0x172/0x1b0 net/socket.c:1100 ____sys_recvmsg+0x1e6/0x4a0 net/socket.c:2812 ___sys_recvmsg+0x215/0x590 net/socket.c:2854 __sys_recvmsg net/socket.c:2887 [inline] __do_sys_recvmsg net/socket.c:2893 [inline] __se_sys_recvmsg net/socket.c:2890 [inline] __x64_sys_recvmsg+0x1ba/0x2a0 net/socket.c:2890 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: ffff88806665c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806665c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806665c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806665c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806665c200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================