From: Dan Carpenter Date: Tue, 3 Sep 2013 09:03:40 +0000 (+0300) Subject: x25: add a sanity check parsing X.25 facilities X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=80aa4e10963cc7d9b5dd5b2568ce28d74af20bf9;p=openwrt%2Fstaging%2Fblogic.git 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 Signed-off-by: David S. Miller --- diff --git a/net/x25/x25_facilities.c b/net/x25/x25_facilities.c index 66c638730c7a..b8253250d723 100644 --- a/net/x25/x25_facilities.c +++ b/net/x25/x25_facilities.c @@ -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;