On Sun, Jul 30, 2017 at 11:23 PM, Yujuan Qi <[email protected]> wrote:
> From: "yujuan.qi" <[email protected]>
>
> in for(),if((optlen > 0) && (optptr[1] == 0)), enter infinite loop.
>
> Test: receive a packet which the ip length > 20 and the first byte of ip option is 0, produce this issue
>
> Signed-off-by: yujuan.qi <[email protected]>
> ---
> net/ipv4/cipso_ipv4.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
Considering I gave you the code below I should probably ack it, right? ;)
Acked-by: Paul Moore <[email protected]>
> diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
> index ae20616..0d1e07d 100644
> --- a/net/ipv4/cipso_ipv4.c
> +++ b/net/ipv4/cipso_ipv4.c
> @@ -1523,9 +1523,17 @@ unsigned char *cipso_v4_optptr(const struct sk_buff *skb)
> int taglen;
>
> for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 0; ) {
> - if (optptr[0] == IPOPT_CIPSO)
> + switch (optptr[0]) {
> + case IPOPT_CIPSO:
> return optptr;
> - taglen = optptr[1];
> + case IPOPT_END:
> + return NULL;
> + case IPOPT_NOOP:
> + taglen = 1;
> + break;
> + default:
> + taglen = optptr[1];
> + }
> optlen -= taglen;
> optptr += taglen;
> }
--
paul moore
security @ redhat