lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Thu, 1 Sep 2022 12:49:15 -0700
From:   Jakub Kicinski <>
To:     Kees Cook <>
Cc:     "David S. Miller" <>,
        Eric Dumazet <>,
        Paolo Abeni <>,
        Pablo Neira Ayuso <>,
        Jozsef Kadlecsik <>,
        Florian Westphal <>,
        syzbot <>,
        Yajun Deng <>,,,,
        Oliver Hartkopp <>,
        Harshit Mogalapalli <>,,
Subject: Re: [PATCH 1/2] netlink: Bounds-check nlmsg_len()

On Wed, 31 Aug 2022 23:27:08 -0700 Kees Cook wrote:
> This would catch corrupted values...
> Is the concern the growth in image size? The check_sub_overflow() isn't
> large at all -- it's just adding a single overflow bit test. The WARNs
> are heavier, but they're all out-of-line.

It turns the most obvious function into a noodle bar :(

Looking at this function in particular is quite useful, because 
it clearly indicates that the nlmsg_len includes the header.

How about we throw in a

	WARN_ON_ONCE(nlh->nlmsg_len < NLMSG_HDRLEN ||
		     nlh->nlmsg_len > INT_MAX);

but leave the actual calculation human readable C?

Powered by blists - more mailing lists