firmware: dmi_scan: Fix UUID length safety check
PATCH 1/1 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.
--- drivers/firmware/dmi_scan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/firmware/dmi_scan.c +1 -1
@@ -186,7 +186,7 @@ static void __init dmi_save_uuid(const schar *s;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 ; d = (u8 *) dm + index;
Signature · 2 lines
Jean Delvare SUSE L3 Support
Quoted 11 lines · Jean Delvare
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 <[email protected]>Fixes a814c3597a6b ("firmware: dmi_scan: Check DMI structure length")Cc Mika Westerberg <[email protected]>