mtdparts: fixed buffer overflow bug

In the case that there was no name defined for a partition the code assumes that name_len is 22 and therefore allocates exactly that space for a dummy name. But the function sprintf() first resolves "0x%08llx at 0x%08llx" to a string that is longer than 22 bytes. This leads to a buffer overflow. The replacement function snprintf() limits the copied bytes to name_len and therefore avoids the buffer overflow.

---
 cmd/mtdparts.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 9bc977450cf8..d0cda1bea400 100644
@@ -691,7 +691,7 @@ static int part_parse(const char *const partdef, const char **ret, struct part_i
 		part->auto_name = 0;
 	} else {
 		/* auto generated name in form of size at offset */
-		sprintf(part->name, "0x%08llx at 0x%08llx", size, offset);
+		snprintf(part->name, name_len, "0x%08llx at 0x%08llx", size, offset);
 		part->auto_name = 1;
 	}
 

2.17.0

Applied to u-boot/master, thanks!

Tom
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