netlink: 168 bytes leftover after parsing attributes in process `syz-executor3'. ================================================================== BUG: KASAN: use-after-free in __write_once_size include/linux/compiler.h:218 [inline] BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:702 [inline] BUG: KASAN: use-after-free in hlist_del_init include/linux/list.h:717 [inline] BUG: KASAN: use-after-free in __xfrm_policy_unlink+0x977/0xa00 net/xfrm/xfrm_policy.c:2213 Write of size 8 at addr ffff888094c76868 by task syz-executor3/29389 CPU: 0 PID: 29389 Comm: syz-executor3 Not tainted 5.0.0-rc2+ #7 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1db/0x2d0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_store8_noabort+0x17/0x20 mm/kasan/generic_report.c:140 __write_once_size include/linux/compiler.h:218 [inline] __hlist_del include/linux/list.h:702 [inline] hlist_del_init include/linux/list.h:717 [inline] __xfrm_policy_unlink+0x977/0xa00 net/xfrm/xfrm_policy.c:2213 xfrm_policy_flush+0x331/0x460 net/xfrm/xfrm_policy.c:1789 xfrm_flush_policy+0x166/0x470 net/xfrm/xfrm_user.c:2129 xfrm_user_rcv_msg+0x458/0x8d0 net/xfrm/xfrm_user.c:2663 netlink_rcv_skb+0x17d/0x410 net/netlink/af_netlink.c:2477 xfrm_netlink_rcv+0x70/0x90 net/xfrm/xfrm_user.c:2671 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x574/0x770 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa05/0xf90 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:631 ___sys_sendmsg+0x7ec/0x910 net/socket.c:2116 __sys_sendmsg+0x112/0x270 net/socket.c:2154 __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg net/socket.c:2161 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458099 Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fb1385cfc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099 RDX: 0000000000000000 RSI: 000000002014f000 RDI: 0000000000000003 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb1385d06d4 R13: 00000000004c562b R14: 00000000004d9298 R15: 00000000ffffffff Allocated by task 27006: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:496 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504 __do_kmalloc_node mm/slab.c:3673 [inline] __kmalloc_node_track_caller+0x4e/0x70 mm/slab.c:3687 __kmalloc_reserve.isra.0+0x40/0xe0 net/core/skbuff.c:140 __alloc_skb+0x12d/0x730 net/core/skbuff.c:208 alloc_skb include/linux/skbuff.h:1011 [inline] alloc_skb_with_frags+0xef/0x720 net/core/skbuff.c:5283 sock_alloc_send_pskb+0x8c9/0xad0 net/core/sock.c:2091 sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2108 __ip_append_data.isra.0+0x1b47/0x3350 net/ipv4/ip_output.c:998 ip_make_skb+0x2b8/0x350 net/ipv4/ip_output.c:1531 udp_sendmsg+0x28b5/0x3a40 net/ipv4/udp.c:1173 udpv6_sendmsg+0x1843/0x3570 net/ipv6/udp.c:1279 inet_sendmsg+0x1af/0x740 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:631 ___sys_sendmsg+0x409/0x910 net/socket.c:2116 __sys_sendmmsg+0x246/0x730 net/socket.c:2211 __do_sys_sendmmsg net/socket.c:2240 [inline] __se_sys_sendmmsg net/socket.c:2237 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2237 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 27006: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466 __cache_free mm/slab.c:3487 [inline] kfree+0xcf/0x230 mm/slab.c:3806 skb_free_head+0x93/0xb0 net/core/skbuff.c:553 skb_release_data+0x6ea/0x970 net/core/skbuff.c:573 skb_release_all+0x4d/0x60 net/core/skbuff.c:627 __kfree_skb net/core/skbuff.c:641 [inline] kfree_skb net/core/skbuff.c:659 [inline] kfree_skb+0x199/0x580 net/core/skbuff.c:653 ip_tunnel_xmit+0x800/0x3b3c net/ipv4/ip_tunnel.c:788 ipip_tunnel_xmit+0x25c/0x2a0 net/ipv4/ipip.c:307 __netdev_start_xmit include/linux/netdevice.h:4382 [inline] netdev_start_xmit include/linux/netdevice.h:4391 [inline] xmit_one net/core/dev.c:3278 [inline] dev_hard_start_xmit+0x261/0xc70 net/core/dev.c:3294 __dev_queue_xmit+0x2f8a/0x3a60 net/core/dev.c:3864 dev_queue_xmit+0x18/0x20 net/core/dev.c:3897 neigh_direct_output+0x16/0x20 net/core/neighbour.c:1516 neigh_output include/net/neighbour.h:508 [inline] ip_finish_output2+0xa35/0x1a00 net/ipv4/ip_output.c:229 ip_finish_output+0x7e4/0xf60 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip_output+0x226/0x880 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:444 [inline] ip_local_out+0xc4/0x1b0 net/ipv4/ip_output.c:124 ip_send_skb+0x42/0xf0 net/ipv4/ip_output.c:1465 udp_send_skb.isra.0+0x6b2/0x1160 net/ipv4/udp.c:891 udp_sendmsg+0x2902/0x3a40 net/ipv4/udp.c:1178 udpv6_sendmsg+0x1843/0x3570 net/ipv6/udp.c:1279 inet_sendmsg+0x1af/0x740 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:631 ___sys_sendmsg+0x409/0x910 net/socket.c:2116 __sys_sendmmsg+0x246/0x730 net/socket.c:2211 __do_sys_sendmmsg net/socket.c:2240 [inline] __se_sys_sendmmsg net/socket.c:2237 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2237 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888094c764c0 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 936 bytes inside of 1024-byte region [ffff888094c764c0, ffff888094c768c0) The buggy address belongs to the page: page:ffffea0002531d80 count:1 mapcount:0 mapping:ffff88812c3f0ac0 index:0xffff888094c76940 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0001ad7c88 ffffea000183a188 ffff88812c3f0ac0 raw: ffff888094c76940 ffff888094c76040 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888094c76700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888094c76780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888094c76800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888094c76880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888094c76900: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ==================================================================