strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
Direct replacement is safe here since return value of -errno
is used to check for truncation instead of sizeof(dest).
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Message-ID: <
20230615180504.401169-1-azeemshaikh38@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
static ssize_t match_busid_store(struct device_driver *dev, const char *buf,
size_t count)
{
- int len;
char busid[BUSID_SIZE];
if (count < 5)
return -EINVAL;
/* busid needs to include \0 termination */
- len = strlcpy(busid, buf + 4, BUSID_SIZE);
- if (sizeof(busid) <= len)
+ if (strscpy(busid, buf + 4, BUSID_SIZE) < 0)
return -EINVAL;
if (!strncmp(buf, "add ", 4)) {