Commit 5317797e authored by Justin Stitt's avatar Justin Stitt Committed by Helge Deller
Browse files

video: hdmi: prefer length specifier in format over string copying 

strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

It looks like the main use of strncpy() here is to limit the amount of
bytes printed from hdmi_log() by using a tmp buffer and limiting the
number of bytes copied. Really, we should use the %.<len>s format
qualifier to achieve this.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html
Link: https://github.com/KSPP/linux/issues/90


Cc: linux-hardening@vger.kernel.org
Signed-off-by: default avatarJustin Stitt <justinstitt@google.com>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
parent 91bcea42

drivers/video/hdmi.c

+2 −8
Original line number Diff line number Diff line
@@ -1310,17 +1310,11 @@ static void hdmi_spd_infoframe_log(const char *level, 
				   struct device *dev,

				   const struct hdmi_spd_infoframe *frame)

{

	u8 buf[17];



	hdmi_infoframe_log_header(level, dev,

				  (const struct hdmi_any_infoframe *)frame);



	memset(buf, 0, sizeof(buf));



	strncpy(buf, frame->vendor, 8);

	hdmi_log("    vendor: %s\n", buf);

	strncpy(buf, frame->product, 16);

	hdmi_log("    product: %s\n", buf);

	hdmi_log("    vendor: %.8s\n", frame->vendor);

	hdmi_log("    product: %.16s\n", frame->product);

	hdmi_log("    source device information: %s (0x%x)\n",

		hdmi_spd_sdi_get_name(frame->sdi), frame->sdi);

}