================================================================== BUG: KASAN: use-after-free in __nft_trace_packet+0x12c/0x154 net/netfilter/nf_tables_core.c:30 Read of size 2 at addr ffff0000e22a56c0 by task ksoftirqd/1/20 CPU: 1 PID: 20 Comm: ksoftirqd/1 Not tainted 5.15.168-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call trace: dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 print_address_description+0x7c/0x3f0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x174/0x1e4 mm/kasan/report.c:451 __asan_report_load2_noabort+0x44/0x50 mm/kasan/report_generic.c:307 __nft_trace_packet+0x12c/0x154 net/netfilter/nf_tables_core.c:30 __nft_trace_verdict+0x74/0x94 net/netfilter/nf_tables_core.c:100 nft_trace_verdict net/netfilter/nf_tables_core.c:110 [inline] nft_do_chain+0x10e8/0x1304 net/netfilter/nf_tables_core.c:256 nft_do_chain_inet+0x2fc/0x50c net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xc8/0x1f4 net/netfilter/core.c:584 nf_hook include/linux/netfilter.h:257 [inline] NF_HOOK+0x228/0x3d0 include/linux/netfilter.h:300 ip_local_deliver+0x11c/0x190 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:453 [inline] ip_rcv_finish+0x22c/0x264 net/ipv4/ip_input.c:447 NF_HOOK+0x324/0x3d0 include/linux/netfilter.h:302 ip_rcv+0x78/0x98 net/ipv4/ip_input.c:566 __netif_receive_skb_one_core net/core/dev.c:5489 [inline] __netif_receive_skb+0x18c/0x400 net/core/dev.c:5603 process_backlog+0x3ec/0x7e0 net/core/dev.c:6480 __napi_poll+0xb4/0x624 net/core/dev.c:7039 napi_poll net/core/dev.c:7106 [inline] net_rx_action+0x500/0xc10 net/core/dev.c:7196 handle_softirqs+0x384/0xdbc kernel/softirq.c:558 run_ksoftirqd+0x6c/0x29c kernel/softirq.c:925 smpboot_thread_fn+0x4b0/0x920 kernel/smpboot.c:164 kthread+0x37c/0x45c 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+0x74/0x3f4 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] kmem_cache_alloc_node+0x208/0x49c mm/slub.c:3256 __alloc_skb+0x174/0x584 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1162 [inline] synproxy_send_client_synack+0x158/0xb24 net/netfilter/nf_synproxy_core.c:482 nft_synproxy_eval_v4+0x18c/0x2ec net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x2cc/0x6a4 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+0x44c/0x1304 net/netfilter/nf_tables_core.c:238 nft_do_chain_inet+0x2fc/0x50c net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xc8/0x1f4 net/netfilter/core.c:584 nf_hook include/linux/netfilter.h:257 [inline] NF_HOOK+0x228/0x3d0 include/linux/netfilter.h:300 ip_local_deliver+0x11c/0x190 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:453 [inline] ip_rcv_finish+0x22c/0x264 net/ipv4/ip_input.c:447 NF_HOOK+0x324/0x3d0 include/linux/netfilter.h:302 ip_rcv+0x78/0x98 net/ipv4/ip_input.c:566 __netif_receive_skb_one_core net/core/dev.c:5489 [inline] __netif_receive_skb+0x18c/0x400 net/core/dev.c:5603 process_backlog+0x3ec/0x7e0 net/core/dev.c:6480 __napi_poll+0xb4/0x624 net/core/dev.c:7039 napi_poll net/core/dev.c:7106 [inline] net_rx_action+0x500/0xc10 net/core/dev.c:7196 handle_softirqs+0x384/0xdbc kernel/softirq.c:558 run_ksoftirqd+0x6c/0x29c kernel/softirq.c:925 smpboot_thread_fn+0x4b0/0x920 kernel/smpboot.c:164 kthread+0x37c/0x45c 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+0x128/0x1ec mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0xdc/0x3c4 mm/slub.c:3515 kfree_skbmem+0x114/0x1b0 __kfree_skb net/core/skbuff.c:757 [inline] consume_skb+0x140/0x40c net/core/skbuff.c:914 nft_synproxy_eval_v4+0x1d4/0x2ec nft_synproxy_do_eval+0x2cc/0x6a4 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+0x44c/0x1304 net/netfilter/nf_tables_core.c:238 nft_do_chain_inet+0x2fc/0x50c net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xc8/0x1f4 net/netfilter/core.c:584 nf_hook include/linux/netfilter.h:257 [inline] NF_HOOK+0x228/0x3d0 include/linux/netfilter.h:300 ip_local_deliver+0x11c/0x190 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:453 [inline] ip_rcv_finish+0x22c/0x264 net/ipv4/ip_input.c:447 NF_HOOK+0x324/0x3d0 include/linux/netfilter.h:302 ip_rcv+0x78/0x98 net/ipv4/ip_input.c:566 __netif_receive_skb_one_core net/core/dev.c:5489 [inline] __netif_receive_skb+0x18c/0x400 net/core/dev.c:5603 process_backlog+0x3ec/0x7e0 net/core/dev.c:6480 __napi_poll+0xb4/0x624 net/core/dev.c:7039 napi_poll net/core/dev.c:7106 [inline] net_rx_action+0x500/0xc10 net/core/dev.c:7196 handle_softirqs+0x384/0xdbc kernel/softirq.c:558 run_ksoftirqd+0x6c/0x29c kernel/softirq.c:925 smpboot_thread_fn+0x4b0/0x920 kernel/smpboot.c:164 kthread+0x37c/0x45c kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 The buggy address belongs to the object at ffff0000e22a5640 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 128 bytes inside of 232-byte region [ffff0000e22a5640, ffff0000e22a5728) The buggy address belongs to the page: page:00000000b5cd0dd4 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1222a5 flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 0000000000000000 dead000000000122 ffff0000c0862000 raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000e22a5580: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff0000e22a5600: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff0000e22a5680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000e22a5700: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ffff0000e22a5780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================