================================================================== BUG: KASAN: use-after-free in xfrm_policy_insert_inexact_list net/xfrm/xfrm_policy.c:1497 [inline] BUG: KASAN: use-after-free in xfrm_policy_inexact_insert+0xcd1/0xee0 net/xfrm/xfrm_policy.c:1202 Read of size 1 at addr ffff8881c5eb6fd9 by task syz-executor3/17743 CPU: 0 PID: 17743 Comm: syz-executor3 Not tainted 4.20.0-rc7+ #360 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+0x1d3/0x2c6 lib/dump_stack.c:113 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430 xfrm_policy_insert_inexact_list net/xfrm/xfrm_policy.c:1497 [inline] xfrm_policy_inexact_insert+0xcd1/0xee0 net/xfrm/xfrm_policy.c:1202 xfrm_policy_insert+0x639/0x850 net/xfrm/xfrm_policy.c:1570 xfrm_add_policy+0x2a0/0x6f0 net/xfrm/xfrm_user.c:1657 xfrm_user_rcv_msg+0x44c/0x8e0 net/xfrm/xfrm_user.c:2663 netlink_rcv_skb+0x16c/0x430 net/netlink/af_netlink.c:2477 xfrm_netlink_rcv+0x6f/0x90 net/xfrm/xfrm_user.c:2671 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x59f/0x750 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2116 __sys_sendmsg+0x11d/0x280 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+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457759 Code: fd b3 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f9cd2826c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457759 RDX: 0000000000000000 RSI: 000000002014f000 RDI: 0000000000000005 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9cd28276d4 R13: 00000000004c4a19 R14: 00000000004d8100 R15: 00000000ffffffff Allocated by task 15226: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 __do_kmalloc_node mm/slab.c:3684 [inline] __kmalloc_node_track_caller+0x50/0x70 mm/slab.c:3698 __kmalloc_reserve.isra.40+0x41/0xe0 net/core/skbuff.c:140 __alloc_skb+0x155/0x760 net/core/skbuff.c:208 alloc_skb include/linux/skbuff.h:1011 [inline] alloc_skb_with_frags+0x133/0x7c0 net/core/skbuff.c:5288 sock_alloc_send_pskb+0x865/0xab0 net/core/sock.c:2091 sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2108 __ip6_append_data.isra.50+0x253c/0x3f50 net/ipv6/ip6_output.c:1443 ip6_make_skb+0x380/0x5e0 net/ipv6/ip6_output.c:1806 udpv6_sendmsg+0x2d37/0x36a0 net/ipv6/udp.c:1460 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x51d/0x930 net/socket.c:2116 __sys_sendmmsg+0x246/0x6d0 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+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 15226: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3817 skb_free_head+0x93/0xb0 net/core/skbuff.c:553 skb_release_data+0x706/0x990 net/core/skbuff.c:573 skb_release_all+0x4a/0x60 net/core/skbuff.c:627 __kfree_skb net/core/skbuff.c:641 [inline] kfree_skb+0x1bb/0x580 net/core/skbuff.c:659 __neigh_event_send+0x89e/0x1390 net/core/neighbour.c:1148 neigh_event_send include/net/neighbour.h:443 [inline] neigh_resolve_output+0x6d0/0xad0 net/core/neighbour.c:1455 neigh_output include/net/neighbour.h:508 [inline] ip6_finish_output2+0xc9c/0x2930 net/ipv6/ip6_output.c:120 ip6_finish_output+0x583/0xc50 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x232/0x9d0 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:444 [inline] ip6_local_out+0xc5/0x1b0 net/ipv6/output_core.c:176 ip6_send_skb+0xbc/0x340 net/ipv6/ip6_output.c:1727 udp_v6_send_skb.isra.32+0x831/0x14a0 net/ipv6/udp.c:1169 udpv6_sendmsg+0x2d86/0x36a0 net/ipv6/udp.c:1466 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x51d/0x930 net/socket.c:2116 __sys_sendmmsg+0x246/0x6d0 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+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8881c5eb6dc0 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 537 bytes inside of 1024-byte region [ffff8881c5eb6dc0, ffff8881c5eb71c0) The buggy address belongs to the page: page:ffffea000717ad80 count:1 mapcount:0 mapping:ffff8881da800ac0 index:0xffff8881c5eb6dc0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea000713f888 ffffea0006e5e308 ffff8881da800ac0 raw: ffff8881c5eb6dc0 ffff8881c5eb6040 0000000100000004 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881c5eb6e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881c5eb6f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881c5eb6f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881c5eb7000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881c5eb7080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================