Commit 90fe6f8f authored Apr 13, 2018 by Jean Delvare

firmware: dmi_scan: Fix UUID length safety check

The test which ensures that the DMI type 1 structure is long enough
to hold the UUID is off by one. It would fail if the structure is
exactly 24 bytes long, while that's sufficient to hold the UUID.

I don't expect this bug to cause problem in practice because all
implementations I have seen had length 8, 25 or 27 bytes, in line
with the SMBIOS specifications. But let's fix it still.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: a814c359 ("firmware: dmi_scan: Check DMI structure length")
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

parent 0adb3285

drivers/firmware/dmi_scan.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -186,7 +186,7 @@ static void __init dmi_save_uuid(const struct dmi_header *dm, int slot,
	char *s;		char *s;
	int is_ff = 1, is_00 = 1, i;		int is_ff = 1, is_00 = 1, i;

	if (dmi_ident[slot] \|\| dm->length <= index + 16)		if (dmi_ident[slot] \|\| dm->length < index + 16)
	return;		return;

	d = (u8 *) dm + index;		d = (u8 *) dm + index;