================================================================== BUG: KASAN: slab-out-of-bounds in ip6_dst_idev include/net/ip6_fib.h:141 [inline] BUG: KASAN: slab-out-of-bounds in ip6_xmit+0x1838/0x1b80 net/ipv6/ip6_output.c:254 Read of size 8 at addr ffff8801cac23b58 by task syz-executor2/6491 CPU: 0 PID: 6491 Comm: syz-executor2 Not tainted 4.9.124-g09eb2ba #83 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801a0a3f540 ffffffff81eb95e9 ffffea00072b08c0 ffff8801cac23b58 0000000000000000 ffff8801cac23b58 0000000000000040 ffff8801a0a3f578 ffffffff8156c35e ffff8801cac23b58 0000000000000008 0000000000000000[ 89.065070] syz-executor4 (6496) used greatest stack depth: 23384 bytes left Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_address_description+0x6c/0x234 mm/kasan/report.c:256 [] kasan_report_error mm/kasan/report.c:355 [inline] [] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 [] ip6_dst_idev include/net/ip6_fib.h:141 [inline] [] ip6_xmit+0x1838/0x1b80 net/ipv6/ip6_output.c:254 input: syz1 as /devices/virtual/input/input4 [] inet6_csk_xmit+0x27c/0x4d0 net/ipv6/inet6_connection_sock.c:178 [] l2tp_xmit_core net/l2tp/l2tp_core.c:1178 [inline] [] l2tp_xmit_skb+0xc45/0xf30 net/l2tp/l2tp_core.c:1273 [] pppol2tp_sendmsg+0x4e0/0x790 net/l2tp/l2tp_ppp.c:339 [] sock_sendmsg_nosec net/socket.c:648 [inline] [] sock_sendmsg+0xcc/0x110 net/socket.c:658 [] ___sys_sendmsg+0x47a/0x840 net/socket.c:1982 [] __sys_sendmmsg+0x161/0x3d0 net/socket.c:2072 [] SYSC_sendmmsg net/socket.c:2103 [inline] [] SyS_sendmmsg+0x35/0x60 net/socket.c:2098 [] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Allocated by task 0: (stack is not available) Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff8801cac23b40 which belongs to the cache ip_dst_cache of size 216 The buggy address is located 24 bytes inside of 216-byte region [ffff8801cac23b40, ffff8801cac23c18) The buggy address belongs to the page: page:ffffea00072b08c0 count:1 mapcount:0 mapping: (null) index:0x0 flags: 0x8000000000000080(slab) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801cac23a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801cac23a80: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc >ffff8801cac23b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8801cac23b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801cac23c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================