================================================================== BUG: KASAN: use-after-free in __nft_trace_packet+0x130/0x14c net/netfilter/nf_tables_core.c:30 Read of size 2 at addr ffff0000f22e3d00 by task ksoftirqd/1/20 CPU: 1 PID: 20 Comm: ksoftirqd/1 Not tainted 5.15.183-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call trace: dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106 print_address_description+0x78/0x30c mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xec/0x15c mm/kasan/report.c:451 __asan_report_load2_noabort+0x44/0x50 mm/kasan/report_generic.c:307 __nft_trace_packet+0x130/0x14c net/netfilter/nf_tables_core.c:30 __nft_trace_verdict+0x64/0x94 net/netfilter/nf_tables_core.c:100 nft_trace_verdict net/netfilter/nf_tables_core.c:110 [inline] nft_do_chain+0xf24/0x1100 net/netfilter/nf_tables_core.c:256 nft_do_chain_inet+0x1e0/0x2b4 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xb4/0x1f4 net/netfilter/core.c:584 nf_hook include/linux/netfilter.h:257 [inline] NF_HOOK+0x1c4/0x354 include/linux/netfilter.h:300 ip_local_deliver+0x120/0x194 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:462 [inline] ip_rcv_finish+0x228/0x260 net/ipv4/ip_input.c:447 NF_HOOK+0x2c0/0x354 include/linux/netfilter.h:302 ip_rcv+0x7c/0x9c net/ipv4/ip_input.c:566 __netif_receive_skb_one_core net/core/dev.c:5525 [inline] __netif_receive_skb+0xcc/0x2ac net/core/dev.c:5639 process_backlog+0x3c8/0x744 net/core/dev.c:6516 __napi_poll+0xb4/0x5dc net/core/dev.c:7075 napi_poll net/core/dev.c:7142 [inline] net_rx_action+0x468/0xa08 net/core/dev.c:7232 handle_softirqs+0x344/0xbf0 kernel/softirq.c:558 run_ksoftirqd+0x7c/0x2a0 kernel/softirq.c:925 smpboot_thread_fn+0x4b0/0x920 kernel/smpboot.c:164 kthread+0x374/0x454 kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 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+0x8c/0xcc mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x74/0x408 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] kmem_cache_alloc_node+0x204/0x41c mm/slub.c:3256 __alloc_skb+0x134/0x67c net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1162 [inline] synproxy_send_client_synack+0x120/0xaec net/netfilter/nf_synproxy_core.c:482 nft_synproxy_eval_v4+0x17c/0x2b8 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x2c0/0x484 net/netfilter/nft_synproxy.c:141 nft_synproxy_eval+0x34/0x48 net/netfilter/nft_synproxy.c:247 expr_call_ops_eval net/netfilter/nf_tables_core.c:198 [inline] nft_do_chain+0x3f0/0x1100 net/netfilter/nf_tables_core.c:238 nft_do_chain_inet+0x1e0/0x2b4 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xb4/0x1f4 net/netfilter/core.c:584 nf_hook include/linux/netfilter.h:257 [inline] NF_HOOK+0x1c4/0x354 include/linux/netfilter.h:300 ip_local_deliver+0x120/0x194 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:462 [inline] ip_rcv_finish+0x228/0x260 net/ipv4/ip_input.c:447 NF_HOOK+0x2c0/0x354 include/linux/netfilter.h:302 ip_rcv+0x7c/0x9c net/ipv4/ip_input.c:566 __netif_receive_skb_one_core net/core/dev.c:5525 [inline] __netif_receive_skb+0xcc/0x2ac net/core/dev.c:5639 process_backlog+0x3c8/0x744 net/core/dev.c:6516 __napi_poll+0xb4/0x5dc net/core/dev.c:7075 napi_poll net/core/dev.c:7142 [inline] net_rx_action+0x468/0xa08 net/core/dev.c:7232 handle_softirqs+0x344/0xbf0 kernel/softirq.c:558 run_ksoftirqd+0x7c/0x2a0 kernel/softirq.c:925 smpboot_thread_fn+0x4b0/0x920 kernel/smpboot.c:164 kthread+0x374/0x454 kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 Freed by task 20: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4c/0x84 mm/kasan/common.c:46 kasan_set_free_info+0x28/0x4c mm/kasan/generic.c:360 ____kasan_slab_free+0x118/0x164 mm/kasan/common.c:366 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0x128/0x1e8 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0xdc/0x3b4 mm/slub.c:3515 kfree_skbmem+0x114/0x1b0 net/core/skbuff.c:-1 __kfree_skb net/core/skbuff.c:757 [inline] consume_skb+0x140/0x33c net/core/skbuff.c:914 nft_synproxy_eval_v4+0x184/0x2b8 net/netfilter/nft_synproxy.c:-1 nft_synproxy_do_eval+0x2c0/0x484 net/netfilter/nft_synproxy.c:141 nft_synproxy_eval+0x34/0x48 net/netfilter/nft_synproxy.c:247 expr_call_ops_eval net/netfilter/nf_tables_core.c:198 [inline] nft_do_chain+0x3f0/0x1100 net/netfilter/nf_tables_core.c:238 nft_do_chain_inet+0x1e0/0x2b4 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xb4/0x1f4 net/netfilter/core.c:584 nf_hook include/linux/netfilter.h:257 [inline] NF_HOOK+0x1c4/0x354 include/linux/netfilter.h:300 ip_local_deliver+0x120/0x194 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:462 [inline] ip_rcv_finish+0x228/0x260 net/ipv4/ip_input.c:447 NF_HOOK+0x2c0/0x354 include/linux/netfilter.h:302 ip_rcv+0x7c/0x9c net/ipv4/ip_input.c:566 __netif_receive_skb_one_core net/core/dev.c:5525 [inline] __netif_receive_skb+0xcc/0x2ac net/core/dev.c:5639 process_backlog+0x3c8/0x744 net/core/dev.c:6516 __napi_poll+0xb4/0x5dc net/core/dev.c:7075 napi_poll net/core/dev.c:7142 [inline] net_rx_action+0x468/0xa08 net/core/dev.c:7232 handle_softirqs+0x344/0xbf0 kernel/softirq.c:558 run_ksoftirqd+0x7c/0x2a0 kernel/softirq.c:925 smpboot_thread_fn+0x4b0/0x920 kernel/smpboot.c:164 kthread+0x374/0x454 kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 The buggy address belongs to the object at ffff0000f22e3c80 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 128 bytes inside of 232-byte region [ffff0000f22e3c80, ffff0000f22e3d68) The buggy address belongs to the page: page:0000000015f2a829 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1322e3 flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 0000000000000000 dead000000000122 ffff0000c085a000 raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f22e3c00: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ffff0000f22e3c80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000f22e3d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ^ ffff0000f22e3d80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff0000f22e3e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================