netlink: 17 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 17 bytes leftover after parsing attributes in process `syz-executor0'. IPv6: IPV6: multipath route replace failed (check consistency of installed routes): :: nexthop :: ifi 1 IPv6: IPV6: multipath route replace failed (check consistency of installed routes): :: nexthop :: ifi 13 ================================================================== BUG: KASAN: use-after-free in ip6_route_mpath_notify+0xe9/0x100 net/ipv6/route.c:4180 Read of size 4 at addr ffff8801af5de230 by task syz-executor0/4759 CPU: 0 PID: 4759 Comm: syz-executor0 Not tainted 4.17.0-rc7+ #103 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+0x1b9/0x294 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 ip6_route_mpath_notify+0xe9/0x100 net/ipv6/route.c:4180 ip6_route_multipath_add+0x615/0x1910 net/ipv6/route.c:4303 inet6_rtm_newroute+0xe3/0x160 net/ipv6/route.c:4391 rtnetlink_rcv_msg+0x466/0xc10 net/core/rtnetlink.c:4646 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2448 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4664 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x58b/0x740 net/netlink/af_netlink.c:1336 netlink_sendmsg+0x9f0/0xfa0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:639 ___sys_sendmsg+0x805/0x940 net/socket.c:2117 __sys_sendmsg+0x115/0x270 net/socket.c:2155 __compat_sys_sendmsg net/compat.c:756 [inline] __do_compat_sys_sendmsg net/compat.c:763 [inline] __se_compat_sys_sendmsg net/compat.c:760 [inline] __ia32_compat_sys_sendmsg+0x7a/0xb0 net/compat.c:760 do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline] do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7feccb9 RSP: 002b:00000000ffa43c3c EFLAGS: 00000282 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000080 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 4759: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554 dst_alloc+0xbb/0x1d0 net/core/dst.c:104 __ip6_dst_alloc+0x35/0xa0 net/ipv6/route.c:361 ip6_dst_alloc+0x29/0xb0 net/ipv6/route.c:376 ip6_route_info_create+0x4d4/0x3a30 net/ipv6/route.c:2834 ip6_route_multipath_add+0xc7e/0x1910 net/ipv6/route.c:4240 inet6_rtm_newroute+0xe3/0x160 net/ipv6/route.c:4391 rtnetlink_rcv_msg+0x466/0xc10 net/core/rtnetlink.c:4646 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2448 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4664 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x58b/0x740 net/netlink/af_netlink.c:1336 netlink_sendmsg+0x9f0/0xfa0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:639 ___sys_sendmsg+0x805/0x940 net/socket.c:2117 __sys_sendmsg+0x115/0x270 net/socket.c:2155 __compat_sys_sendmsg net/compat.c:756 [inline] __do_compat_sys_sendmsg net/compat.c:763 [inline] __se_compat_sys_sendmsg net/compat.c:760 [inline] __ia32_compat_sys_sendmsg+0x7a/0xb0 net/compat.c:760 do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline] do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Freed by task 4759: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x2d0 mm/slab.c:3756 dst_destroy+0x267/0x3c0 net/core/dst.c:140 dst_release_immediate+0x71/0x9e net/core/dst.c:205 fib6_add+0xa40/0x1650 net/ipv6/ip6_fib.c:1305 __ip6_ins_rt+0x6c/0x90 net/ipv6/route.c:1011 ip6_route_multipath_add+0x513/0x1910 net/ipv6/route.c:4267 inet6_rtm_newroute+0xe3/0x160 net/ipv6/route.c:4391 rtnetlink_rcv_msg+0x466/0xc10 net/core/rtnetlink.c:4646 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2448 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4664 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x58b/0x740 net/netlink/af_netlink.c:1336 netlink_sendmsg+0x9f0/0xfa0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:639 ___sys_sendmsg+0x805/0x940 net/socket.c:2117 __sys_sendmsg+0x115/0x270 net/socket.c:2155 __compat_sys_sendmsg net/compat.c:756 [inline] __do_compat_sys_sendmsg net/compat.c:763 [inline] __se_compat_sys_sendmsg net/compat.c:760 [inline] __ia32_compat_sys_sendmsg+0x7a/0xb0 net/compat.c:760 do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline] do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 The buggy address belongs to the object at ffff8801af5de180 which belongs to the cache ip6_dst_cache of size 320 The buggy address is located 176 bytes inside of 320-byte region [ffff8801af5de180, ffff8801af5de2c0) The buggy address belongs to the page: page:ffffea0006bd7780 count:1 mapcount:0 mapping:ffff8801af5de000 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801af5de000 0000000000000000 000000010000000a raw: ffffea000759c6a0 ffff8801cd9d3448 ffff8801ce1d0000 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801af5de100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801af5de180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801af5de200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801af5de280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8801af5de300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================