Date: Sat, 16 Sep 2017 23:04:57 -0700 From: Eric Biggers <ebiggers3@...il.com> To: "Jason A. Donenfeld" <Jason@...c4.com> Cc: linux-security-module@...r.kernel.org, keyrings@...r.kernel.org, kernel-hardening@...ts.openwall.com, linux-kernel@...r.kernel.org, dhowells@...hat.com, Herbert Xu <herbert@...dor.apana.org.au>, Kirill Marinushkin <k.marinushkin@...il.com>, security@...nel.org, stable@...r.kernel.org Subject: Re: [PATCH v5] security/keys: rewrite all of big_key crypto Hi Jason, On Sat, Sep 16, 2017 at 03:05:33PM +0200, Jason A. Donenfeld wrote: > - > - ret = big_key_gen_enckey(enckey); > - if (ret) > - goto err_enckey; > + ret = get_random_bytes_wait(enckey, ENC_KEY_SIZE); > + if (unlikely(ret)) > + goto error; This should jump to 'err_enckey', otherwise it will leak 'enckey'. Otherwise the changes all look good; after fixing the above, feel free to add my Reviewed-by. Yes, AES-GCM is the right choice here. It is, however, almost certainly the case that if someone can modify your swap partition, they can already own your system in many other ways, so the "authenticated" portion of "authenticated encryption" may not actually buy much in this situation :-) The patch is a little long and perhaps should be split into several patches, each of which fixes one bug; but see what David thinks. I should also note, that while there definitely were some inadmissible bugs here, the support for encrypting big_key's was only added recently, in the v4.7 kernel. And obviously not encrypting at all is at least as much as a "vulnerability" as using weak encryption. I'm also a little skeptical that people actually care enough about big_key's for it to be worthwhile to mark a rewrite like this for stable, though I suppose it wouldn't be *too* hard to at least cherry-pick this to 4.9 if you wanted. (There is a small conflict so you'd have to send the backport yourself after this goes into mainline.) Eric
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.