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From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: jlbec@evilplan.org
Cc: ocfs2-devel@oss.oracle.com, reiserfs-devel@vger.kernel.org,
	eparis@parisplace.org, casey@schaufler-ca.com, zohar@us.ibm.com,
	serge.hallyn@canonical.com, linux-fsdevel@vger.kernel.org,
	linux-security-module@vger.kernel.org
Subject: Re: [PATCH] xattr: Constify ->name member of "struct xattr".
Date: Sun, 9 Jun 2013 21:09:56 +0900	[thread overview]
Message-ID: <201306092109.GBB81777.JOHtFOMQVLSFOF@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <20130609090721.GD5531@localhost>

Joel Becker wrote:
> I can't really comment on the concept, but if security folks agree, the
> ocfs2 part looks fine.

This is merely a bugfix/cleanup with a bit of cpu usage reduction.

I noticed that EVM by error returns "struct xattr"->name == NULL and
"struct xattr"->value != NULL if kstrdup(XATTR_EVM_SUFFIX, GFP_NOFS) failed,
resulting in EVM security attribute not associated with inode and leak memory.
The proposed (but now turned out to be incorrect) fix is
http://marc.info/?l=linux-security-module&m=136965357007829&w=2 .

But I also noticed that all of SELinux, Smack and EVM sets "struct xattr"->name
a kstrdup()ed constant suffix. Therefore, if passing constant suffix
("const char *") rather than kstrdup()ed constant suffix ("char *") does not
break "struct xattr"->name users, SELinux, Smack and EVM can omit kstrdup()ing
their constant suffix. Therefore, I'm querying you whether changing from
"char *name" to "const char *name" breaks your filesystem.

If my proposal breaks your filesystem, I'm happy to fix only EVM code.

Regards.

WARNING: multiple messages have this Message-ID (diff)
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: jlbec@evilplan.org
Cc: ocfs2-devel@oss.oracle.com, reiserfs-devel@vger.kernel.org,
	eparis@parisplace.org, casey@schaufler-ca.com, zohar@us.ibm.com,
	serge.hallyn@canonical.com, linux-fsdevel@vger.kernel.org,
	linux-security-module@vger.kernel.org
Subject: [Ocfs2-devel] [PATCH] xattr: Constify ->name member of "struct xattr".
Date: Sun, 09 Jun 2013 12:10:47 -0000	[thread overview]
Message-ID: <201306092109.GBB81777.JOHtFOMQVLSFOF@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <20130609090721.GD5531@localhost>

Joel Becker wrote:
> I can't really comment on the concept, but if security folks agree, the
> ocfs2 part looks fine.

This is merely a bugfix/cleanup with a bit of cpu usage reduction.

I noticed that EVM by error returns "struct xattr"->name == NULL and
"struct xattr"->value != NULL if kstrdup(XATTR_EVM_SUFFIX, GFP_NOFS) failed,
resulting in EVM security attribute not associated with inode and leak memory.
The proposed (but now turned out to be incorrect) fix is
http://marc.info/?l=linux-security-module&m=136965357007829&w=2 .

But I also noticed that all of SELinux, Smack and EVM sets "struct xattr"->name
a kstrdup()ed constant suffix. Therefore, if passing constant suffix
("const char *") rather than kstrdup()ed constant suffix ("char *") does not
break "struct xattr"->name users, SELinux, Smack and EVM can omit kstrdup()ing
their constant suffix. Therefore, I'm querying you whether changing from
"char *name" to "const char *name" breaks your filesystem.

If my proposal breaks your filesystem, I'm happy to fix only EVM code.

Regards.

  reply	other threads:[~2013-06-09 12:09 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-29 12:52 [RFC] xattr: Constify ->name member of "struct xattr" Tetsuo Handa
2013-06-08 12:54 ` [PATCH] " Tetsuo Handa
2013-06-08 12:55   ` [Ocfs2-devel] " Tetsuo Handa
2013-06-08 12:54   ` Tetsuo Handa
2013-06-09  9:07   ` Joel Becker
2013-06-09  9:07     ` [Ocfs2-devel] " Joel Becker
2013-06-09 12:09     ` Tetsuo Handa [this message]
2013-06-09 12:10       ` Tetsuo Handa
2013-06-24 13:05       ` Tetsuo Handa
2013-06-24 13:05         ` Tetsuo Handa
     [not found]         ` <201307231723.GBI69775.VSOLHFQFOOtJMF@I-love.SAKURA.ne.jp>
2013-07-24 19:34           ` Eric Paris
2013-06-10 11:54   ` Serge Hallyn
2013-06-10 11:54     ` [Ocfs2-devel] " Serge Hallyn
2013-06-10 15:53   ` Casey Schaufler
2013-06-10 15:53     ` [Ocfs2-devel] " Casey Schaufler
2013-07-23 18:27   ` Paul Moore
2013-07-23 18:27     ` [Ocfs2-devel] " Paul Moore
2013-07-23 18:27     ` Paul Moore

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