Re: [patch] smack: remove unnecessary xattr checks

From: Casey Schaufler
Date: Tue Jul 01 2008 - 17:47:32 EST


Miklos Szeredi wrote:
Hi Casey,

This is an untested patch, if it looks OK, can you please apply it to
your tree (or ACK it)?


I will give it some review and a test or two
then let you know. Things are hopping right now,
so it may take a day or two.

Thank you for the work you've put into this.

Thanks,
Miklos

----
From: Miklos Szeredi <mszeredi@xxxxxxx>

getxattr() calls security_inode_permission(MAY_READ) so
smack_inode_getxattr() is unnecessary.

setxattr() and removexattr() call security_inode_permission(MAY_WRITE)
so the write permission checks in smack_inode_setxattr() and
smack_inode_removexattr() are unnecessary.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
---
security/smack/smack_lsm.c | 19 -------------------
1 file changed, 19 deletions(-)

Index: linux-2.6/security/smack/smack_lsm.c
===================================================================
--- linux-2.6.orig/security/smack/smack_lsm.c 2008-07-01 21:44:05.000000000 +0200
+++ linux-2.6/security/smack/smack_lsm.c 2008-07-01 21:45:27.000000000 +0200
@@ -588,9 +588,6 @@ static int smack_inode_setxattr(struct d
} else
rc = cap_inode_setxattr(dentry, name, value, size, flags);
- if (rc == 0)
- rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
-
return rc;
}
@@ -636,18 +633,6 @@ static void smack_inode_post_setxattr(st
}
/*
- * smack_inode_getxattr - Smack check on getxattr
- * @dentry: the object
- * @name: unused
- *
- * Returns 0 if access is permitted, an error code otherwise
- */
-static int smack_inode_getxattr(struct dentry *dentry, const char *name)
-{
- return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ);
-}
-
-/*
* smack_inode_removexattr - Smack check on removexattr
* @dentry: the object
* @name: name of the attribute
@@ -668,9 +653,6 @@ static int smack_inode_removexattr(struc
} else
rc = cap_inode_removexattr(dentry, name);
- if (rc == 0)
- rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
-
return rc;
}
@@ -2606,7 +2588,6 @@ struct security_operations smack_ops = {
.inode_getattr = smack_inode_getattr,
.inode_setxattr = smack_inode_setxattr,
.inode_post_setxattr = smack_inode_post_setxattr,
- .inode_getxattr = smack_inode_getxattr,
.inode_removexattr = smack_inode_removexattr,
.inode_need_killpriv = cap_inode_need_killpriv,
.inode_killpriv = cap_inode_killpriv,




--

----------------------

Casey Schaufler
casey@xxxxxxxxxxxxxxxx
650.906.1780


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