From: james.l.morris@oracle.com (James Morris)
To: linux-security-module@vger.kernel.org
Subject: [PATCH] KEYS: trusted: fix writing past end of buffer in trusted_read()
Date: Fri, 27 Oct 2017 09:55:39 +0200 (CEST) [thread overview]
Message-ID: <alpine.LFD.2.20.1710270954210.2635@localhost> (raw)
In-Reply-To: <20171026205744.105566-1-ebiggers3@gmail.com>
On Thu, 26 Oct 2017, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
>
> When calling keyctl_read() on a key of type "trusted", if the
> user-supplied buffer was too small, the kernel ignored the buffer length
> and just wrote past the end of the buffer, potentially corrupting
> userspace memory. Fix it by instead returning the size required, as per
> the documentation for keyctl_read().
>
> We also don't even fill the buffer at all in this case, as this is
> slightly easier to implement than doing a short read, and either
> behavior appears to be permitted. It also makes it match the behavior
> of the "encrypted" key type.
>
> Fixes: d00a1c72f7f4 ("keys: add new trusted key-type")
> Reported-by: Ben Hutchings <ben@decadent.org.uk>
> Cc: <stable@vger.kernel.org> # v2.6.38+
> Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
--
James Morris
<james.l.morris@oracle.com>
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next prev parent reply other threads:[~2017-10-27 7:55 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-26 20:57 [PATCH] KEYS: trusted: fix writing past end of buffer in trusted_read() Eric Biggers
2017-10-26 23:57 ` Mimi Zohar
2017-10-27 7:55 ` James Morris [this message]
2017-11-01 6:55 ` James Morris
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