When the soft-version partition contents are checked for a text-format
version string, isascii() is used to check the contained bytes. This
also returns true on control characters, which includes terminating
NULL characters.
After checking if the data is a string, use the actual string length for
printing the contained data to avoid outputting NULLs to stdout.
Signed-off-by: Sander Vanheule <san...@svanheule.net>
---
src/tplink-safeloader.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
diff --git a/src/tplink-safeloader.c b/src/tplink-safeloader.c
index 05b7ca17f786..51f6683c802a 100644
--- a/src/tplink-safeloader.c
+++ b/src/tplink-safeloader.c
@@ -3928,18 +3928,16 @@ static int firmware_info(const char *input)
if (fread(buf, data_len, 1, fp) != 1)
error(1, errno, "Can not read fwup-ptn data from the
firmware");
- /* Check for string ignoring padding character */
- isstr = true;
- for (i = 0; i < data_len - 1; i++) {
- if (!isascii(buf[i])) {
- isstr = false;
- break;
- }
- }
+ /* Check for (null-terminated) string */
+ ascii_len = 0;
+ while (ascii_len < data_len && isascii(buf[ascii_len]))
+ ascii_len++;
+
+ isstr = ascii_len == data_len;
printf("\n[Software version]\n");
if (isstr) {
- fwrite(buf, data_len, 1, stdout);
+ fwrite(buf, strnlen(buf, data_len), 1, stdout);
putchar('\n');
} else if (data_len >= offsetof(struct soft_version, rev)) {
s = (struct soft_version *)buf;
--
2.39.0
_______________________________________________
openwrt-devel mailing list
openwrt-devel@lists.openwrt.org
https://lists.openwrt.org/mailman/listinfo/openwrt-devel
