Re: [PATCH] firmware: dmi_scan: Prevent dmi_num integer overflow

[Jean Delvare <jdelvare@suse.de>]

Hi Matt,

Le Thursday 26 March 2015 à 13:06 +0000, Matt Fleming a écrit :
> On Fri, 20 Mar, at 09:59:47AM, Jean Delvare wrote:
> > dmi_num is a u16, dmi_len is a u32, so this construct:
> > 
> > 	dmi_num = dmi_len / 4;
> > 
> > would result in an integer overflow for a DMI table larger than
> > 256 kB. I've never see such a large table so far, but SMBIOS 3.0
> > makes it possible so maybe we'll see such tables in the future.
> > 
> > So instead of faking a structure count when the entry point does
> > not provide it, adjust the loop condition in dmi_table() to properly
> > deal with the case where dmi_num is not set.
> > 
> > Signed-off-by: Jean Delvare <jdelvare@suse.de>
> > Cc: Matt Fleming <matt.fleming@intel.com>
> > Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> > Cc: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
> > ---
> >  drivers/firmware/dmi_scan.c |   22 +++++++---------------
> >  1 file changed, 7 insertions(+), 15 deletions(-)
> 
> Jean, are you taking this through your tree?

I don't actually have a tree, so feel free to pick it.

Thanks,
-- 
Jean Delvare
SUSE L3 Support