Currently when the current line should be removed from the display
kdb_read() uses memset() to fill a temporary buffer with spaces.
The problem is not that this could be trivially implemented using a
format string rather than open coding it. The real problem is that
it is possible, on systems with a long kdb_prompt_str, to write past
the end of the tmpbuffer.
Happily, as mentioned above, this can be trivially implemented using a
format string. Make it so!
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Tested-by: Justin Stitt <justinstitt@xxxxxxxxxx>
Signed-off-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
---
kernel/debug/kdb/kdb_io.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index a73779529803f..2aeaf9765b248 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -318,11 +318,9 @@ static char *kdb_read(char *buffer, size_t bufsize)
break;
case 14: /* Down */
case 16: /* Up */
- memset(tmpbuffer, ' ',
- strlen(kdb_prompt_str) + (lastchar-buffer));
- *(tmpbuffer+strlen(kdb_prompt_str) +
- (lastchar-buffer)) = '\0';
- kdb_printf("\r%s\r", tmpbuffer);
+ kdb_printf("\r%*c\r",
+ (int)(strlen(kdb_prompt_str) + (lastchar - buffer)),
+ ' ');
*lastchar = (char)key;
*(lastchar+1) = '\0';
return lastchar;
--
2.43.0
