================================================================== BUG: KASAN: use-after-free in __nft_trace_packet+0x135/0x150 net/netfilter/nf_tables_core.c:30 Read of size 2 at addr ffff88804005ce40 by task syz.7.1815/16126 CPU: 1 PID: 16126 Comm: syz.7.1815 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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:5551 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5665 netif_receive_skb_internal net/core/dev.c:5751 [inline] netif_receive_skb+0x19e/0x700 net/core/dev.c:5810 tun_rx_batched+0x5fb/0x760 drivers/net/tun.c:-1 tun_get_user+0x2517/0x3a70 drivers/net/tun.c:1989 tun_chr_write_iter+0x112/0x1e0 drivers/net/tun.c:2019 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x745/0xd60 fs/read_write.c:594 ksys_write+0x152/0x260 fs/read_write.c:647 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: 0033:0x7f730c44f68e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007f730a6e7fb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f730a6e86c0 RCX: 00007f730c44f68e RDX: 0000000000000036 RSI: 0000200000000140 RDI: 00000000000000c8 RBP: 00007f730c524d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f730c708038 R14: 00007f730c707fa0 R15: 00007fff18e6fe38 Allocated by task 16126: 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] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3238 __build_skb+0x26/0x2e0 net/core/skbuff.c:241 build_skb+0x1e/0x170 net/core/skbuff.c:258 __tun_build_skb+0x32/0x240 drivers/net/tun.c:1589 tun_build_skb drivers/net/tun.c:1674 [inline] tun_get_user+0x19f7/0x3a70 drivers/net/tun.c:1797 tun_chr_write_iter+0x112/0x1e0 drivers/net/tun.c:2019 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x745/0xd60 fs/read_write.c:594 ksys_write+0x152/0x260 fs/read_write.c:647 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 16126: 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_v4+0x34f/0x4e0 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x304/0x570 net/netfilter/nft_synproxy.c:141 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:5551 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5665 netif_receive_skb_internal net/core/dev.c:5751 [inline] netif_receive_skb+0x19e/0x700 net/core/dev.c:5810 tun_rx_batched+0x5fb/0x760 drivers/net/tun.c:-1 tun_get_user+0x2517/0x3a70 drivers/net/tun.c:1989 tun_chr_write_iter+0x112/0x1e0 drivers/net/tun.c:2019 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x745/0xd60 fs/read_write.c:594 ksys_write+0x152/0x260 fs/read_write.c:647 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 ffff88804005cdc0 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 128 bytes inside of 232-byte region [ffff88804005cdc0, ffff88804005cea8) The buggy address belongs to the page: page:ffffea0001001700 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4005c memcg:ffff88807d49c681 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea000187db40 0000000b00000002 ffff88801bbe4140 raw: 0000000000000000 00000000800c000c 00000001ffffffff ffff88807d49c681 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 12115, ts 494416518488, free_ts 483980412784 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:5501 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 skb_copy+0x139/0x790 net/core/skbuff.c:1595 mac80211_hwsim_tx_frame_no_nl+0xce0/0x1600 drivers/net/wireless/mac80211_hwsim.c:1569 mac80211_hwsim_tx_frame+0x1b5/0x200 drivers/net/wireless/mac80211_hwsim.c:1788 mac80211_hwsim_beacon_tx+0x4f3/0x920 drivers/net/wireless/mac80211_hwsim.c:1842 __iterate_interfaces+0x243/0x500 net/mac80211/util.c:793 ieee80211_iterate_active_interfaces_atomic+0xb3/0x140 net/mac80211/util.c:829 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4f2/0xb70 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766 handle_softirqs+0x339/0x830 kernel/softirq.c:576 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_pages_ok+0x89f/0x940 mm/page_alloc.c:1643 free_nonslab_page+0xe2/0x150 mm/slub.c:3540 btrfs_free_stripe_hash_table+0xd5/0x110 fs/btrfs/raid56.c:443 btrfs_free_fs_info+0x8c/0x280 fs/btrfs/disk-io.c:1567 deactivate_locked_super+0x93/0xf0 fs/super.c:335 btrfs_mount_root+0x771/0x930 fs/btrfs/super.c:1757 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 fc_mount fs/namespace.c:1005 [inline] vfs_kern_mount+0xba/0x150 fs/namespace.c:1035 btrfs_mount+0x342/0xb10 fs/btrfs/super.c:1811 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3034 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562 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: ffff88804005cd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff88804005cd80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff88804005ce00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804005ce80: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ffff88804005cf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================