x25: add a sanity check parsing X.25 facilities

This was found with a manual audit and I don't have a reproducer.  We
limit ->calling_len and ->called_len when we get them from
copy_from_user() in x25_ioctl() so when they come from skb->data then
we should cap them there as well.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dan Carpenter 2013-09-03 12:03:40 +03:00 committed by David S. Miller
parent cab6ce9ebe
commit 80aa4e1096
1 changed files with 4 additions and 0 deletions

View File

@ -156,6 +156,8 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities,
case X25_FAC_CALLING_AE:
if (p[1] > X25_MAX_DTE_FACIL_LEN || p[1] <= 1)
return -1;
if (p[2] > X25_MAX_AE_LEN)
return -1;
dte_facs->calling_len = p[2];
memcpy(dte_facs->calling_ae, &p[3], p[1] - 1);
*vc_fac_mask |= X25_MASK_CALLING_AE;
@ -163,6 +165,8 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities,
case X25_FAC_CALLED_AE:
if (p[1] > X25_MAX_DTE_FACIL_LEN || p[1] <= 1)
return -1;
if (p[2] > X25_MAX_AE_LEN)
return -1;
dte_facs->called_len = p[2];
memcpy(dte_facs->called_ae, &p[3], p[1] - 1);
*vc_fac_mask |= X25_MASK_CALLED_AE;