memory corruption in X.25 facilities parsing

Signed-of-by: Andrew Hendry <andrew.hendry@gmail.com>

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/x25/x25_facilities.c b/net/x25/x25_facilities.c
index 771bab0..3a8c4c4 100644
--- a/net/x25/x25_facilities.c
+++ b/net/x25/x25_facilities.c
@@ -134,15 +134,15 @@
 		case X25_FAC_CLASS_D:
 			switch (*p) {
 			case X25_FAC_CALLING_AE:
-				if (p[1] > X25_MAX_DTE_FACIL_LEN)
-					break;
+				if (p[1] > X25_MAX_DTE_FACIL_LEN || p[1] <= 1)
+					return 0;
 				dte_facs->calling_len = p[2];
 				memcpy(dte_facs->calling_ae, &p[3], p[1] - 1);
 				*vc_fac_mask |= X25_MASK_CALLING_AE;
 				break;
 			case X25_FAC_CALLED_AE:
-				if (p[1] > X25_MAX_DTE_FACIL_LEN)
-					break;
+				if (p[1] > X25_MAX_DTE_FACIL_LEN || p[1] <= 1)
+					return 0;
 				dte_facs->called_len = p[2];
 				memcpy(dte_facs->called_ae, &p[3], p[1] - 1);
 				*vc_fac_mask |= X25_MASK_CALLED_AE;