From: Gavrilov Ilia <Ilia.Gavrilov@xxxxxxxxxxx>
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@xxxxxxxxxxx>
Reviewed-by: Jiri Pirko <jiri@xxxxxxxxxx>
Reviewed-by: David Ahern <dsahern@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv6/exthdrs_core.c | 2 ++
1 file changed, 2 insertions(+)
--- a/net/ipv6/exthdrs_core.c
+++ b/net/ipv6/exthdrs_core.c
@@ -142,6 +142,8 @@ 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;
