optlen is fetched without checking whether there is more than one byte to parse.
It can lead to out-of-bounds access.
Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with SVACE.
Fixes:
c61a40432509 ("[IPV6]: Find option offset by type.")
Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
optlen = 1;
break;
default:
+ if (len < 2)
+ goto bad;
optlen = nh[offset + 1] + 2;
if (optlen > len)
goto bad;