| Message ID | YsVA9KoY/ZSvNGYk@kili (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] can: slcan: use scnprintf() as a hardening measure | expand |
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;
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@oracle.com> --- drivers/net/can/slcan/slcan-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)