From: Gavrilov Ilia Ilia.Gavrilov@infotecs.ru
commit 878ecb0897f4737a4c9401f3523fd49589025671 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/exthdrs_core.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/net/ipv6/exthdrs_core.c +++ b/net/ipv6/exthdrs_core.c @@ -143,6 +143,8 @@ int ipv6_find_tlv(const struct sk_buff * optlen = 1; break; default: + if (len < 2) + goto bad; optlen = nh[offset + 1] + 2; if (optlen > len) goto bad;