GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
==================================================================
BUG: KASAN: use-after-free in __nft_trace_packet+0x135/0x150 net/netfilter/nf_tables_core.c:30
Read of size 2 at addr ffff8880236e0300 by task syz.3.237/5125

CPU: 1 PID: 5125 Comm: syz.3.237 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <IRQ>
 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
 process_backlog+0x370/0x790 net/core/dev.c:6542
 __napi_poll+0xc0/0x430 net/core/dev.c:7101
 napi_poll net/core/dev.c:7168 [inline]
 net_rx_action+0x4d4/0xa10 net/core/dev.c:7258
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 do_softirq+0x142/0x210 kernel/softirq.c:477
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x180/0x1c0 kernel/softirq.c:401
 rcu_read_unlock_bh include/linux/rcupdate.h:810 [inline]
 ip6_finish_output2+0x1127/0x1510 net/ipv6/ip6_output.c:131
 dst_output include/net/dst.h:452 [inline]
 NF_HOOK include/linux/netfilter.h:302 [inline]
 ip6_xmit+0x109b/0x16d0 net/ipv6/ip6_output.c:338
 inet6_csk_xmit+0x405/0x680 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x1d11/0x3200 net/ipv4/tcp_output.c:1404
 tcp_transmit_skb net/ipv4/tcp_output.c:1422 [inline]
 tcp_send_syn_data net/ipv4/tcp_output.c:3864 [inline]
 tcp_connect+0x2d71/0x4970 net/ipv4/tcp_output.c:3903
 tcp_v6_connect+0x1224/0x1a30 net/ipv6/tcp_ipv6.c:337
 __inet_stream_connect+0x244/0xd70 net/ipv4/af_inet.c:672
 tcp_sendmsg_fastopen+0x38f/0x600 net/ipv4/tcp.c:1198
 tcp_sendmsg_locked+0x2efa/0x3320 net/ipv4/tcp.c:1240
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1460
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 __sys_sendto+0x46d/0x620 net/socket.c:2072
 __do_sys_sendto net/socket.c:2084 [inline]
 __se_sys_sendto net/socket.c:2080 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2080
 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: 0033:0x7f80c1260799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f80bf4ba028 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f80c14d9fa0 RCX: 00007f80c1260799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f80c12f6bd9 R08: 0000200000000200 R09: 000000000000001c
R10: 00000000240540c7 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f80c14da038 R14: 00007f80c14d9fa0 R15: 00007ffdb82c1978
 </TASK>

Allocated by task 5125:
 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:5551 [inline]
 __netif_receive_skb+0xcc/0x290 net/core/dev.c:5665
 process_backlog+0x370/0x790 net/core/dev.c:6542
 __napi_poll+0xc0/0x430 net/core/dev.c:7101
 napi_poll net/core/dev.c:7168 [inline]
 net_rx_action+0x4d4/0xa10 net/core/dev.c:7258
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 do_softirq+0x142/0x210 kernel/softirq.c:477
 __local_bh_enable_ip+0x180/0x1c0 kernel/softirq.c:401
 rcu_read_unlock_bh include/linux/rcupdate.h:810 [inline]
 ip6_finish_output2+0x1127/0x1510 net/ipv6/ip6_output.c:131
 dst_output include/net/dst.h:452 [inline]
 NF_HOOK include/linux/netfilter.h:302 [inline]
 ip6_xmit+0x109b/0x16d0 net/ipv6/ip6_output.c:338
 inet6_csk_xmit+0x405/0x680 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x1d11/0x3200 net/ipv4/tcp_output.c:1404
 tcp_transmit_skb net/ipv4/tcp_output.c:1422 [inline]
 tcp_send_syn_data net/ipv4/tcp_output.c:3864 [inline]
 tcp_connect+0x2d71/0x4970 net/ipv4/tcp_output.c:3903
 tcp_v6_connect+0x1224/0x1a30 net/ipv6/tcp_ipv6.c:337
 __inet_stream_connect+0x244/0xd70 net/ipv4/af_inet.c:672
 tcp_sendmsg_fastopen+0x38f/0x600 net/ipv4/tcp.c:1198
 tcp_sendmsg_locked+0x2efa/0x3320 net/ipv4/tcp.c:1240
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1460
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 __sys_sendto+0x46d/0x620 net/socket.c:2072
 __do_sys_sendto net/socket.c:2084 [inline]
 __se_sys_sendto net/socket.c:2080 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2080
 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 5125:
 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:5551 [inline]
 __netif_receive_skb+0xcc/0x290 net/core/dev.c:5665
 process_backlog+0x370/0x790 net/core/dev.c:6542
 __napi_poll+0xc0/0x430 net/core/dev.c:7101
 napi_poll net/core/dev.c:7168 [inline]
 net_rx_action+0x4d4/0xa10 net/core/dev.c:7258
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 do_softirq+0x142/0x210 kernel/softirq.c:477
 __local_bh_enable_ip+0x180/0x1c0 kernel/softirq.c:401
 rcu_read_unlock_bh include/linux/rcupdate.h:810 [inline]
 ip6_finish_output2+0x1127/0x1510 net/ipv6/ip6_output.c:131
 dst_output include/net/dst.h:452 [inline]
 NF_HOOK include/linux/netfilter.h:302 [inline]
 ip6_xmit+0x109b/0x16d0 net/ipv6/ip6_output.c:338
 inet6_csk_xmit+0x405/0x680 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x1d11/0x3200 net/ipv4/tcp_output.c:1404
 tcp_transmit_skb net/ipv4/tcp_output.c:1422 [inline]
 tcp_send_syn_data net/ipv4/tcp_output.c:3864 [inline]
 tcp_connect+0x2d71/0x4970 net/ipv4/tcp_output.c:3903
 tcp_v6_connect+0x1224/0x1a30 net/ipv6/tcp_ipv6.c:337
 __inet_stream_connect+0x244/0xd70 net/ipv4/af_inet.c:672
 tcp_sendmsg_fastopen+0x38f/0x600 net/ipv4/tcp.c:1198
 tcp_sendmsg_locked+0x2efa/0x3320 net/ipv4/tcp.c:1240
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1460
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 __sys_sendto+0x46d/0x620 net/socket.c:2072
 __do_sys_sendto net/socket.c:2084 [inline]
 __se_sys_sendto net/socket.c:2080 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2080
 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 ffff8880236e0280
 which belongs to the cache skbuff_head_cache of size 232
The buggy address is located 128 bytes inside of
 232-byte region [ffff8880236e0280, ffff8880236e0368)
The buggy address belongs to the page:
page:ffffea00008db800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880236e0500 pfn:0x236e0
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea00008b9900 0000000b00000004 ffff888144bf0140
raw: ffff8880236e0500 00000000800c0006 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 4262, ts 65918857996, free_ts 65772321316
 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
 __netdev_alloc_skb+0x110/0x4c0 net/core/skbuff.c:494
 netdev_alloc_skb include/linux/skbuff.h:3024 [inline]
 dev_alloc_skb include/linux/skbuff.h:3037 [inline]
 __ieee80211_beacon_get+0xaa1/0x2000 net/mac80211/tx.c:5088
 ieee80211_beacon_get_tim+0x48/0x840 net/mac80211/tx.c:5202
 ieee80211_beacon_get include/net/mac80211.h:4983 [inline]
 mac80211_hwsim_beacon_tx+0xf4/0x920 drivers/net/wireless/mac80211_hwsim.c:1812
 __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_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
 free_slab mm/slub.c:2020 [inline]
 discard_slab mm/slub.c:2026 [inline]
 __unfreeze_partials+0x1a5/0x200 mm/slub.c:2512
 put_cpu_partial+0x12d/0x190 mm/slub.c:2592
 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:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc_trace+0x103/0x2a0 mm/slub.c:3250
 kmalloc include/linux/slab.h:607 [inline]
 __memcg_init_list_lru_node mm/list_lru.c:339 [inline]
 memcg_update_list_lru_node mm/list_lru.c:396 [inline]
 memcg_update_list_lru mm/list_lru.c:473 [inline]
 memcg_update_all_list_lrus+0x2cc/0xba0 mm/list_lru.c:510
 memcg_alloc_cache_id mm/memcontrol.c:2964 [inline]
 memcg_online_kmem mm/memcontrol.c:3656 [inline]
 mem_cgroup_css_alloc+0xb25/0x1640 mm/memcontrol.c:5310
 css_create kernel/cgroup/cgroup.c:5388 [inline]
 cgroup_apply_control_enable+0x3cc/0xb00 kernel/cgroup/cgroup.c:3212
 cgroup_mkdir+0xcc0/0xec0 kernel/cgroup/cgroup.c:5608
 kernfs_iop_mkdir+0x24c/0x3d0 fs/kernfs/dir.c:1175
 vfs_mkdir+0x387/0x570 fs/namei.c:4073
 do_mkdirat+0x1df/0x5b0 fs/namei.c:4098

Memory state around the buggy address:
 ffff8880236e0200: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc
 ffff8880236e0280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880236e0300: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
                   ^
 ffff8880236e0380: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
 ffff8880236e0400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
vkms_vblank_simulate: vblank timer overrun