Re: CVE-2014-9900 fix is not upstream
From: Johannes Berg <johannes@sipsolutions.net>
Date: 2016-08-25 12:40:19
Also in:
lkml
If we want to go down this route, probably the only option is to add __attribute__((pack)) those structs to just have no padding at all, thus breaking uapi.
We could also spell out the padding bytes as reserved, i.e. instead of
struct ethtool_wolinfo {
__u32 cmd;
__u32 supported;
__u32 wolopts;
__u8 sopass[SOPASS_MAX]; // 6, actually
};
we could do
struct ethtool_wolinfo {
__u32 cmd;
__u32 supported;
__u32 wolopts;
__u8 sopass[SOPASS_MAX]; // 6, actually
__u8 reserved[2];
};
and then the compiler has to properly treat it, since it's no longer
unnamed padding.
Maybe somebody can come up with a smart BUILD_BUG_ON() to ensure such
structs have no padding.
That would allow us to keep the C99 initializers (which is nice) and
not have to worry about this.
johannes