linux-ext4 - Re: [PATCH 1/3] fscrypt: fix loophole in one-encryption-policy-per-tree enforcement

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]

Message-ID: <7ed75b90-864a-2dc2-83a0-943c300d0698@nod.at>
Date:   Fri, 16 Dec 2016 13:18:46 +0100
From:   Richard Weinberger <richard@....at>
To:     Eric Biggers <ebiggers3@...il.com>, linux-fsdevel@...r.kernel.org
Cc:     "Theodore Y . Ts'o" <tytso@....edu>,
        Jaegeuk Kim <jaegeuk@...nel.org>, linux-ext4@...r.kernel.org,
        linux-f2fs-devel@...ts.sourceforge.net,
        David Gstir <david@...ma-star.at>,
        Eric Biggers <ebiggers@...gle.com>
Subject: Re: [PATCH 1/3] fscrypt: fix loophole in
 one-encryption-policy-per-tree enforcement

On 15.12.2016 20:19, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@...gle.com>
> 
> Filesystem encryption is designed to enforce that all files in an
> encrypted directory tree use the same encryption policy.  Operations
> that violate this constraint are supposed to fail with EPERM.  There was
> one case that was missed, however: the cross-rename operation (i.e.
> renameat2 with RENAME_EXCHANGE) allowed two files with different
> encryption policies to be exchanged, provided that neither encryption
> key was available.
> 
> To fix this, when we can't compare the fscrypt_info structs because the
> key is unavailable, compare the fscrypt_context structs instead.
> 
> This will be covered by a test in my encryption xfstests patchset.
> 
> Fixes: b7236e21d55f ("ext4 crypto: reorganize how we store keys in the inode")
> Signed-off-by: Eric Biggers <ebiggers@...gle.com>

Reviewed-by: Richard Weinberger <richard@....at>

Thanks,
//richard
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html