X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=hex.c;h=9ebc050637532765b775cbd8e3b92951a67ea333;hb=bd193f46b70fd3f8a55e2a8dcbb1fb2b4eec13d6;hp=bb402fbaa2a04ef0849789fdd814dcbb8773fff5;hpb=79cfe0c5c4920bf68da548ad0d5bcdb425ce8d5f;p=git.git

diff --git a/hex.c b/hex.c
index bb402fbaa..9ebc05063 100644
--- a/hex.c
+++ b/hex.c
@@ -39,7 +39,15 @@ int get_sha1_hex(const char *hex, unsigned char *sha1)
 {
 	int i;
 	for (i = 0; i < 20; i++) {
-		unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
+		unsigned int val;
+		/*
+		 * hex[1]=='\0' is caught when val is checked below,
+		 * but if hex[0] is NUL we have to avoid reading
+		 * past the end of the string:
+		 */
+		if (!hex[0])
+			return -1;
+		val = (hexval(hex[0]) << 4) | hexval(hex[1]);
 		if (val & ~0xff)
 			return -1;
 		*sha1++ = val;