The snprintf() function returns the number of bytes which *would* have
been copied if there were no space. So, since this code does not check
the return value, there if the buffer was not large enough then there
would be a buffer overflow two lines later when it does:
actual = sl->tty->ops->write(sl->tty, sl->xbuff, n);
Use scnprintf() instead because that returns the number of bytes which
were actually copied.
Fixes: 52f9ac85b876 ("can: slcan: allow to send commands to the adapter")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
drivers/net/can/slcan/slcan-core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/can/slcan/slcan-core.c b/drivers/net/can/slcan/slcan-core.c
index 54d29a410ad5..92bdd49996d1 100644
--- a/drivers/net/can/slcan/slcan-core.c
+++ b/drivers/net/can/slcan/slcan-core.c
@@ -647,7 +647,7 @@ static int slcan_transmit_cmd(struct slcan *sl, const unsigned char *cmd)
return -ENODEV;
}
- n = snprintf(sl->xbuff, sizeof(sl->xbuff), "%s", cmd);
+ n = scnprintf(sl->xbuff, sizeof(sl->xbuff), "%s", cmd);
set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
actual = sl->tty->ops->write(sl->tty, sl->xbuff, n);
sl->xleft = n - actual;
--
2.35.1
