================================================================== BUG: KASAN: use-after-free in __nft_trace_packet+0x135/0x150 net/netfilter/nf_tables_core.c:30 Read of size 2 at addr ffff888062034080 by task udevd/9679 CPU: 0 PID: 9679 Comm: udevd Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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 kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_call_function_single arch/x86/kernel/smp.c:243 [inline] sysvec_call_function_single+0x4f/0xc0 arch/x86/kernel/smp.c:243 asm_sysvec_call_function_single+0x16/0x20 arch/x86/include/asm/idtentry.h:684 RIP: 0033:0x564134204bf0 Code: 68 b9 00 00 00 e9 50 f4 ff ff ff 25 c2 72 04 00 68 ba 00 00 00 e9 40 f4 ff ff ff 25 ba 72 04 00 68 bb 00 00 00 e9 30 f4 ff ff 25 b2 72 04 00 68 bc 00 00 00 e9 20 f4 ff ff ff 25 aa 72 04 00 RSP: 002b:00007ffd2bf0edd8 EFLAGS: 00000206 RAX: 000056414cf1fda0 RBX: 000056414cf23900 RCX: 000056414cf57a20 RDX: 0000000000000028 RSI: 000056414cf1fd98 RDI: 000056414cf1fda0 RBP: 0000000000000005 R08: 000056414cf23900 R09: 000056414cf273e0 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000005 R13: 000056414cf1f3a0 R14: 0000000000000001 R15: 000056414cf579e0 Allocated by task 14: 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:3220 [inline] kmem_cache_alloc_node+0x12d/0x2d0 mm/slub.c:3256 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1162 [inline] synproxy_send_client_synack+0x169/0xdd0 net/netfilter/nf_synproxy_core.c:482 nft_synproxy_eval_v4+0x36b/0x560 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x341/0x570 net/netfilter/nft_synproxy.c:141 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 run_ksoftirqd+0x98/0xf0 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 9679: 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:1705 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3515 nft_synproxy_eval_v4+0x373/0x560 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x341/0x570 net/netfilter/nft_synproxy.c:141 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 kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_call_function_single arch/x86/kernel/smp.c:243 [inline] sysvec_call_function_single+0x4f/0xc0 arch/x86/kernel/smp.c:243 asm_sysvec_call_function_single+0x16/0x20 arch/x86/include/asm/idtentry.h:684 The buggy address belongs to the object at ffff888062034000 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 128 bytes inside of 232-byte region [ffff888062034000, ffff8880620340e8) The buggy address belongs to the page: page:ffffea0001880d00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x62034 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 dead000000000100 dead000000000122 ffff88801b7e4140 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 0x132a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_MEMALLOC|__GFP_HARDWALL), pid 4412, ts 225638592846, free_ts 225618579558 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:5474 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1975 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] kmem_cache_alloc_node+0x1c3/0x2d0 mm/slub.c:3256 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415 __netdev_alloc_skb+0x103/0x4a0 net/core/skbuff.c:494 __netdev_alloc_skb_ip_align include/linux/skbuff.h:3021 [inline] netdev_alloc_skb_ip_align include/linux/skbuff.h:3031 [inline] batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:558 [inline] batadv_iv_ogm_queue_add+0x73e/0xcf0 net/batman-adv/bat_iv_ogm.c:670 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:849 [inline] batadv_iv_ogm_schedule+0xacc/0xe90 net/batman-adv/bat_iv_ogm.c:868 batadv_iv_send_outstanding_bat_ogm_packet+0x72d/0x840 net/batman-adv/bat_iv_ogm.c:1712 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 free_slab mm/slub.c:2015 [inline] discard_slab mm/slub.c:2021 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2507 put_cpu_partial+0x12d/0x190 mm/slub.c:2587 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444 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:3220 [inline] kmem_cache_alloc_node+0x12d/0x2d0 mm/slub.c:3256 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1162 [inline] alloc_skb_with_frags+0xa7/0x730 net/core/skbuff.c:6170 sock_alloc_send_pskb+0x853/0x980 net/core/sock.c:2531 unix_dgram_sendmsg+0x5ef/0x1890 net/unix/af_unix.c:1809 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] sock_write_iter+0x29c/0x380 net/socket.c:1079 do_iter_readv_writev+0x497/0x600 fs/read_write.c:-1 do_iter_write+0x205/0x7b0 fs/read_write.c:855 Memory state around the buggy address: ffff888062033f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888062034000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888062034080: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ^ ffff888062034100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff888062034180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== vkms_vblank_simulate: vblank timer overrun