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@xxxxxxxxxx> --- Possibly should be applied to -stable. My guess is that this leads to memory corruption, but I don't know. diff --git a/net/x25/x25_facilities.c b/net/x25/x25_facilities.c index 66c63873..b825325 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; -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
