linux-kernel - Re: [oss-security] Re: [PATCH v2 4/4] ozwpan: unchecked signed subtraction leads to DoS

lists.openwall.net		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 linux-cve-announce 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:	Tue, 26 May 2015 16:34:55 +0200
From:	"Jason A. Donenfeld" <Jason@...c4.com>
To:	Dan Carpenter <dan.carpenter@...cle.com>
Cc:	linux-kernel@...r.kernel.org,
	Shigekatsu Tateno <shigekatsu.tateno@...el.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	devel@...verdev.osuosl.org
Subject: Re: [oss-security] Re: [PATCH v2 4/4] ozwpan: unchecked signed
 subtraction leads to DoS

On Tue, May 26, 2015 at 4:06 PM, Dan Carpenter <dan.carpenter@...cle.com> wrote:
> You sure do like wrapping to a high value and testing the result for
> wrapping instead of validating before doing the subtraction...

I do indeed. It seems like asking "did it overflow?" is more
straight-forward and easier to read than trying to come up with the
necessary conditions to check for "will it overflow?". Personal
preference, I guess.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/