================================================================== BUG: KASAN: use-after-free in __nft_trace_packet+0x135/0x150 net/netfilter/nf_tables_core.c:30 Read of size 2 at addr ffff8880445cbd00 by task ksoftirqd/1/20 CPU: 1 PID: 20 Comm: ksoftirqd/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x188/0x250 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+0x12a5/0x14f0 net/netfilter/nf_tables_core.c:256 nft_do_chain_inet+0x25c/0x340 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+0x1f2/0x390 include/linux/netfilter.h:300 NF_HOOK+0x303/0x390 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+0x370/0x790 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+0x4d4/0xa10 net/core/dev.c:7232 handle_softirqs+0x339/0x830 kernel/softirq.c:576 run_ksoftirqd+0xa4/0x100 kernel/softirq.c:943 smpboot_thread_fn+0x4f6/0x970 kernel/smpboot.c:164 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 20: 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+0x161/0xc60 net/netfilter/nf_synproxy_core.c:895 nft_synproxy_eval_v6+0x347/0x4e0 net/netfilter/nft_synproxy.c:90 nft_synproxy_do_eval+0x3c9/0x570 net/netfilter/nft_synproxy.c:145 expr_call_ops_eval net/netfilter/nf_tables_core.c:198 [inline] nft_do_chain+0x48c/0x14f0 net/netfilter/nf_tables_core.c:238 nft_do_chain_inet+0x25c/0x340 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+0x1f2/0x390 include/linux/netfilter.h:300 NF_HOOK+0x303/0x390 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+0x370/0x790 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+0x4d4/0xa10 net/core/dev.c:7232 handle_softirqs+0x339/0x830 kernel/softirq.c:576 run_ksoftirqd+0xa4/0x100 kernel/softirq.c:943 smpboot_thread_fn+0x4f6/0x970 kernel/smpboot.c:164 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Freed by task 20: 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+0x34f/0x4e0 net/netfilter/nft_synproxy.c:91 nft_synproxy_do_eval+0x3c9/0x570 net/netfilter/nft_synproxy.c:145 expr_call_ops_eval net/netfilter/nf_tables_core.c:198 [inline] nft_do_chain+0x48c/0x14f0 net/netfilter/nf_tables_core.c:238 nft_do_chain_inet+0x25c/0x340 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+0x1f2/0x390 include/linux/netfilter.h:300 NF_HOOK+0x303/0x390 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+0x370/0x790 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+0x4d4/0xa10 net/core/dev.c:7232 handle_softirqs+0x339/0x830 kernel/softirq.c:576 run_ksoftirqd+0xa4/0x100 kernel/softirq.c:943 smpboot_thread_fn+0x4f6/0x970 kernel/smpboot.c:164 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff8880445cbc80 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 128 bytes inside of 232-byte region [ffff8880445cbc80, ffff8880445cbd68) The buggy address belongs to the page: page:ffffea00011172c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x445cb flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 0000000000000000 dead000000000122 ffff88801bbe4140 raw: 0000000000000000 00000000000c000c 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 20, ts 198842865382, free_ts 198717658199 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 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+0x80a/0xdd0 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] synproxy_send_client_synack_ipv6+0x161/0xc60 net/netfilter/nf_synproxy_core.c:895 nft_synproxy_eval_v6+0x347/0x4e0 net/netfilter/nft_synproxy.c:90 nft_synproxy_do_eval+0x3c9/0x570 net/netfilter/nft_synproxy.c:145 expr_call_ops_eval net/netfilter/nf_tables_core.c:198 [inline] nft_do_chain+0x48c/0x14f0 net/netfilter/nf_tables_core.c:238 nft_do_chain_inet+0x25c/0x340 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+0x1f2/0x390 include/linux/netfilter.h:300 NF_HOOK+0x303/0x390 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+0x370/0x790 net/core/dev.c:6516 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_list+0x119/0x820 mm/page_alloc.c:3433 release_pages+0x186c/0x1be0 mm/swap.c:963 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu mm/mmu_gather.c:247 [inline] tlb_finish_mmu+0x176/0x300 mm/mmu_gather.c:338 exit_mmap+0x3d0/0x640 mm/mmap.c:3218 __mmput+0x115/0x3b0 kernel/fork.c:1127 exit_mm+0x588/0x6e0 kernel/exit.c:550 do_exit+0x5a9/0x20c0 kernel/exit.c:870 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff8880445cbc00: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ffff8880445cbc80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880445cbd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ^ ffff8880445cbd80: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ffff8880445cbe00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================