From: Karel Zak <kzak@redhat.com>
Date: Tue, 7 Oct 2025 10:10:08 +0000 (+0200)
Subject: libfdisk: use snprintf() instead of sprintf()
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=417d8c564905dafb2522ec7f93b6bfd124a35e0f;p=thirdparty%2Futil-linux.git

libfdisk: use snprintf() instead of sprintf()

Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/libfdisk/src/gpt.c b/libfdisk/src/gpt.c
index 8a052852a..298c88a52 100644
--- a/libfdisk/src/gpt.c
+++ b/libfdisk/src/gpt.c
@@ -1736,7 +1736,7 @@ static char *encode_to_utf8(unsigned char *src, size_t count)
 static int gpt_entry_attrs_to_string(struct gpt_entry *e, char **res)
 {
 	unsigned int n, count = 0;
-	size_t l;
+	size_t l, res_size;
 	char *bits, *p;
 	uint64_t attrs;
 
@@ -1752,10 +1752,11 @@ static int gpt_entry_attrs_to_string(struct gpt_entry *e, char **res)
 
 	/* Note that sizeof() is correct here, we need separators between
 	 * the strings so also count \0 is correct */
-	*res = calloc(1, sizeof(GPT_ATTRSTR_NOBLOCK) +
+	res_size = sizeof(GPT_ATTRSTR_NOBLOCK) +
 			 sizeof(GPT_ATTRSTR_REQ) +
 			 sizeof(GPT_ATTRSTR_LEGACY) +
-			 sizeof("GUID:") + (GPT_ATTRBIT_GUID_COUNT * 3));
+			 sizeof("GUID:") + (GPT_ATTRBIT_GUID_COUNT * 3);
+	*res = calloc(1, res_size);
 	if (!*res)
 		return -errno;
 
@@ -1779,15 +1780,20 @@ static int gpt_entry_attrs_to_string(struct gpt_entry *e, char **res)
 
 	for (n = GPT_ATTRBIT_GUID_FIRST;
 	     n < GPT_ATTRBIT_GUID_FIRST + GPT_ATTRBIT_GUID_COUNT; n++) {
+		int rc;
 
 		if (!isset(bits, n))
 			continue;
 		if (!count) {
 			if (p != *res)
 				*p++ = ' ';
-			p += sprintf(p, "GUID:%u", n);
+			rc = snprintf(p, res_size - (p - *res), "GUID:%u", n);
 		} else
-			p += sprintf(p, ",%u", n);
+			rc = snprintf(p, res_size - (p - *res), ",%u", n);
+
+		if (rc < 0 || (size_t) rc >= res_size - (p - *res))
+			break;
+		p += rc;
 		count++;
 	}