From mboxrd@z Thu Jan 1 00:00:00 1970 From: Willy Tarreau Subject: Re: crypto_memneq not backported to 3.10 Date: Sun, 9 Apr 2017 15:25:14 +0200 Message-ID: <20170409132514.GA3970@1wt.eu> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: stable@vger.kernel.org, LKML , Linux Crypto Mailing List To: "Jason A. Donenfeld" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org Hi Jason, On Sun, Apr 09, 2017 at 02:59:53PM +0200, Jason A. Donenfeld wrote: > Hey Willy, > > Linux 3.10 is inexplicably missing crypto_memneq, making all crypto > mac comparisons use non constant-time comparisons. Bad news bears. > > 3.12 got these backported with > d68e944a8fcb2c6212b38064771c9f5af7b0b92c, > afe5a791d374e50a06ada7f4eda4e921e1b77996, and possibly others. I'd > suggest following suit, since many people are relying on this kernel > to do safe crypto. Interesting. I remembered seeing some crypto_memneq stuff in the past, and in fact there was one patch talking about this but trimmed down to only affect other parts since crypto_memneq is indeed not part of 3.10. I'll check if the 3.12 patches above can be safely backported, and I'll have to re-apply the missing part of the one that was trimmed down (commit 620c411 ("crypto: more robust crypto_memneq")). Thanks! Willy