================================================================== BUG: KASAN: use-after-free in __nft_trace_packet+0x135/0x150 net/netfilter/nf_tables_core.c:30 Read of size 2 at addr ffff888077c3d440 by task syz.0.485/6026 CPU: 0 PID: 6026 Comm: syz.0.485 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 __nft_trace_packet+0x135/0x150 net/netfilter/nf_tables_core.c:30 nft_trace_verdict net/netfilter/nf_tables_core.c:110 [inline] nft_do_chain+0x120e/0x1420 net/netfilter/nf_tables_core.c:256 nft_do_chain_inet+0x22b/0x300 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xb9/0x200 net/netfilter/core.c:584 nf_hook include/linux/netfilter.h:257 [inline] NF_HOOK+0x1cb/0x360 include/linux/netfilter.h:300 NF_HOOK+0x2d6/0x360 include/linux/netfilter.h:302 __netif_receive_skb_one_core net/core/dev.c:5525 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5639 process_backlog+0x364/0x780 net/core/dev.c:6516 __napi_poll+0xc0/0x430 net/core/dev.c:7075 napi_poll net/core/dev.c:7142 [inline] net_rx_action+0x4a8/0x9c0 net/core/dev.c:7232 handle_softirqs+0x328/0x820 kernel/softirq.c:576 do_softirq+0x13b/0x200 kernel/softirq.c:477 __local_bh_enable_ip+0x174/0x1b0 kernel/softirq.c:401 rcu_read_unlock_bh include/linux/rcupdate.h:810 [inline] ip6_finish_output2+0x110b/0x1500 net/ipv6/ip6_output.c:131 dst_output include/net/dst.h:452 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ip6_xmit+0x1054/0x1670 net/ipv6/ip6_output.c:338 inet6_csk_xmit+0x444/0x6d0 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x1ced/0x31c0 net/ipv4/tcp_output.c:1404 tcp_transmit_skb net/ipv4/tcp_output.c:1422 [inline] tcp_send_syn_data net/ipv4/tcp_output.c:3864 [inline] tcp_connect+0x2d6e/0x4970 net/ipv4/tcp_output.c:3903 tcp_v6_connect+0x1136/0x1920 net/ipv6/tcp_ipv6.c:337 __inet_stream_connect+0x293/0xdf0 net/ipv4/af_inet.c:672 tcp_sendmsg_fastopen+0x38f/0x600 net/ipv4/tcp.c:1195 tcp_sendmsg_locked+0x3097/0x3590 net/ipv4/tcp.c:1237 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1457 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] __sys_sendto+0x423/0x580 net/socket.c:2073 __do_sys_sendto net/socket.c:2085 [inline] __se_sys_sendto net/socket.c:2081 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2081 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f6d7131a749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6d6f581038 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f6d71570fa0 RCX: 00007f6d7131a749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f6d7139ef91 R08: 00002000000001c0 R09: 000000000000001c R10: 0000000020000045 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6d71571038 R14: 00007f6d71570fa0 R15: 00007fff5b87fdd8 Allocated by task 6026: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] kmem_cache_alloc_node+0x12d/0x2d0 mm/slub.c:3261 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1162 [inline] synproxy_send_client_synack_ipv6+0x15b/0xc50 net/netfilter/nf_synproxy_core.c:895 nft_synproxy_eval_v6+0x36b/0x560 net/netfilter/nft_synproxy.c:90 nft_synproxy_do_eval+0x3d3/0x570 net/netfilter/nft_synproxy.c:145 expr_call_ops_eval net/netfilter/nf_tables_core.c:198 [inline] nft_do_chain+0x3fc/0x1420 net/netfilter/nf_tables_core.c:238 nft_do_chain_inet+0x22b/0x300 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xb9/0x200 net/netfilter/core.c:584 nf_hook include/linux/netfilter.h:257 [inline] NF_HOOK+0x1cb/0x360 include/linux/netfilter.h:300 NF_HOOK+0x2d6/0x360 include/linux/netfilter.h:302 __netif_receive_skb_one_core net/core/dev.c:5525 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5639 process_backlog+0x364/0x780 net/core/dev.c:6516 __napi_poll+0xc0/0x430 net/core/dev.c:7075 napi_poll net/core/dev.c:7142 [inline] net_rx_action+0x4a8/0x9c0 net/core/dev.c:7232 handle_softirqs+0x328/0x820 kernel/softirq.c:576 do_softirq+0x13b/0x200 kernel/softirq.c:477 __local_bh_enable_ip+0x174/0x1b0 kernel/softirq.c:401 rcu_read_unlock_bh include/linux/rcupdate.h:810 [inline] ip6_finish_output2+0x110b/0x1500 net/ipv6/ip6_output.c:131 dst_output include/net/dst.h:452 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ip6_xmit+0x1054/0x1670 net/ipv6/ip6_output.c:338 inet6_csk_xmit+0x444/0x6d0 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x1ced/0x31c0 net/ipv4/tcp_output.c:1404 tcp_transmit_skb net/ipv4/tcp_output.c:1422 [inline] tcp_send_syn_data net/ipv4/tcp_output.c:3864 [inline] tcp_connect+0x2d6e/0x4970 net/ipv4/tcp_output.c:3903 tcp_v6_connect+0x1136/0x1920 net/ipv6/tcp_ipv6.c:337 __inet_stream_connect+0x293/0xdf0 net/ipv4/af_inet.c:672 tcp_sendmsg_fastopen+0x38f/0x600 net/ipv4/tcp.c:1195 tcp_sendmsg_locked+0x3097/0x3590 net/ipv4/tcp.c:1237 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1457 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] __sys_sendto+0x423/0x580 net/socket.c:2073 __do_sys_sendto net/socket.c:2085 [inline] __se_sys_sendto net/socket.c:2081 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2081 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 6026: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3520 nft_synproxy_eval_v6+0x373/0x560 net/netfilter/nft_synproxy.c:91 nft_synproxy_do_eval+0x3d3/0x570 net/netfilter/nft_synproxy.c:145 expr_call_ops_eval net/netfilter/nf_tables_core.c:198 [inline] nft_do_chain+0x3fc/0x1420 net/netfilter/nf_tables_core.c:238 nft_do_chain_inet+0x22b/0x300 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xb9/0x200 net/netfilter/core.c:584 nf_hook include/linux/netfilter.h:257 [inline] NF_HOOK+0x1cb/0x360 include/linux/netfilter.h:300 NF_HOOK+0x2d6/0x360 include/linux/netfilter.h:302 __netif_receive_skb_one_core net/core/dev.c:5525 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5639 process_backlog+0x364/0x780 net/core/dev.c:6516 __napi_poll+0xc0/0x430 net/core/dev.c:7075 napi_poll net/core/dev.c:7142 [inline] net_rx_action+0x4a8/0x9c0 net/core/dev.c:7232 handle_softirqs+0x328/0x820 kernel/softirq.c:576 do_softirq+0x13b/0x200 kernel/softirq.c:477 __local_bh_enable_ip+0x174/0x1b0 kernel/softirq.c:401 rcu_read_unlock_bh include/linux/rcupdate.h:810 [inline] ip6_finish_output2+0x110b/0x1500 net/ipv6/ip6_output.c:131 dst_output include/net/dst.h:452 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ip6_xmit+0x1054/0x1670 net/ipv6/ip6_output.c:338 inet6_csk_xmit+0x444/0x6d0 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x1ced/0x31c0 net/ipv4/tcp_output.c:1404 tcp_transmit_skb net/ipv4/tcp_output.c:1422 [inline] tcp_send_syn_data net/ipv4/tcp_output.c:3864 [inline] tcp_connect+0x2d6e/0x4970 net/ipv4/tcp_output.c:3903 tcp_v6_connect+0x1136/0x1920 net/ipv6/tcp_ipv6.c:337 __inet_stream_connect+0x293/0xdf0 net/ipv4/af_inet.c:672 tcp_sendmsg_fastopen+0x38f/0x600 net/ipv4/tcp.c:1195 tcp_sendmsg_locked+0x3097/0x3590 net/ipv4/tcp.c:1237 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1457 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] __sys_sendto+0x423/0x580 net/socket.c:2073 __do_sys_sendto net/socket.c:2085 [inline] __se_sys_sendto net/socket.c:2081 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2081 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff888077c3d3c0 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 128 bytes inside of 232-byte region [ffff888077c3d3c0, ffff888077c3d4a8) The buggy address belongs to the page: page:ffffea0001df0f40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x77c3d flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea00014790c0 0000000600000006 ffff88801b5e4140 raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 4426, ts 72054192817, free_ts 72046643543 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] kmem_cache_alloc_node+0x1c3/0x2d0 mm/slub.c:3261 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1162 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:664 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:721 [inline] nsim_dev_trap_report_work+0x2a1/0xb40 drivers/net/netdevsim/dev.c:762 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x94/0x280 mm/page_alloc.c:3396 tlb_batch_list_free mm/mmu_gather.c:61 [inline] tlb_finish_mmu+0x236/0x2e0 mm/mmu_gather.c:341 exit_mmap+0x3a6/0x5f0 mm/mmap.c:3218 __mmput+0x115/0x3b0 kernel/fork.c:1127 exit_mm+0x567/0x6c0 kernel/exit.c:550 do_exit+0x5a1/0x20a0 kernel/exit.c:870 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff888077c3d300: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff888077c3d380: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff888077c3d400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888077c3d480: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ffff888077c3d500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================