From: Arnd Bergmann <arnd@arndb.de>
To: David Howells <dhowells@redhat.com>
Cc: keyrings@vger.kernel.org,
David Woodhouse <David.Woodhouse@intel.com>,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
linux-security-module@vger.kernel.org,
Rudolf Polzer <rpolzer@google.com>,
John Stultz <john.stultz@linaro.org>
Subject: Re: [PATCH 3/5] X.509: Support leap seconds
Date: Fri, 18 Dec 2015 10:10:12 +0100 [thread overview]
Message-ID: <10024561.ctYHZaznk8@wuerfel> (raw)
In-Reply-To: <20151218000209.29483.56212.stgit@warthog.procyon.org.uk>
On Friday 18 December 2015 00:02:09 David Howells wrote:
> The format of ASN.1 GeneralizedTime seems to be specified by ISO 8601
> [X.680 46.3] and this apparently supports leap seconds (ie. the seconds
> field is 60). It's not entirely clear that ASN.1 expects it, but we can
> relax the seconds check slightly for GeneralizedTime.
>
> This, however, results in us passing a time with sec as 60 to mktime64()
> which, unpatched, doesn't really handle such things. What it will do is
> equate the 60th second of a minute to the 0th second of the next minute.
>
> We can't really do otherwise without giving the kernel much greater
> knowledge of where all the leap seconds are. Unfortunately, this would
> require change the mapping of the kernel's current-time-in-seconds.
>
> UTCTime, however, only supports a seconds value in the range 00-59.
>
> Without this patch, certain X.509 certificates will be rejected,
> potentially making a kernel unbootable.
>
> Reported-by: Rudolf Polzer <rpolzer@google.com>
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: David Woodhouse <David.Woodhouse@intel.com>
> cc: John Stultz <john.stultz@linaro.org>
> cc: Arnd Bergmann <arnd@arndb.de>
> cc: stable@vger.kernel.org
Acked-by: Arnd Bergmann <arnd@arndb.de>
next prev parent reply other threads:[~2015-12-18 9:10 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20151218000148.29483.67155.stgit@warthog.procyon.org.uk>
2015-12-18 0:01 ` [PATCH 1/5] X.509: Fix leap year handling again David Howells
2015-12-18 0:02 ` [PATCH 2/5] Handle leap seconds in mktime64() David Howells
2015-12-18 9:09 ` Arnd Bergmann
2015-12-18 0:02 ` [PATCH 3/5] X.509: Support leap seconds David Howells
2015-12-18 9:10 ` Arnd Bergmann [this message]
2015-12-18 0:02 ` [PATCH 4/5] Handle both ISO 8601 encodings of midnight in mktime64() David Howells
2015-12-18 9:11 ` Arnd Bergmann
2015-12-18 0:02 ` [PATCH 5/5] X.509: Handle midnight alternative notation in GeneralizedTime David Howells
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