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[PATCH] move executable checking into ->permission()

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For execute permission on a regular files we need to check if file has
any execute bits at all, regardless of capabilites.

This check is normally performed by generic_permission() but was also
added to the case when the filesystem defines its own ->permission()
method.  In the latter case the filesystem should be responsible for
performing this check.

Move the check from inode_permission() inside filesystems which are
not calling generic_permission().

Create a helper function execute_ok() that returns true if the inode
is a directory or if any execute bits are present in i_mode.

Also fix up the following code:

 - coda control file is never executable
 - sysctl files are never executable
 - hfs_permission seems broken on MAY_EXEC, remove
 - hfsplus_permission is eqivalent to generic_permission(), remove

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
This commit is contained in:
Miklos Szeredi
2008-07-31 13:41:58 +02:00
committed by Al Viro
parent 5cec56deb6
commit f696a3659f
9 changed files with 30 additions and 44 deletions
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21
fs/namei.c
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@@ -212,8 +212,7 @@ int generic_permission(struct inode *inode, int mask,
* Read/write DACs are always overridable.
* Executable DACs are overridable if at least one exec bit is set.
*/
if (!(mask & MAY_EXEC) ||
(inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode))
if (!(mask & MAY_EXEC) || execute_ok(inode))
if (capable(CAP_DAC_OVERRIDE))
return 0;
@@ -249,23 +248,11 @@ int inode_permission(struct inode *inode, int mask)
}
/* Ordinary permission routines do not understand MAY_APPEND. */
if (inode->i_op && inode->i_op->permission) {
if (inode->i_op && inode->i_op->permission)
retval = inode->i_op->permission(inode, mask);
if (!retval) {
/*
* Exec permission on a regular file is denied if none
* of the execute bits are set.
*
* This check should be done by the ->permission()
* method.
*/
if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode) &&
!(inode->i_mode & S_IXUGO))
return -EACCES;
}
} else {
else
retval = generic_permission(inode, mask, NULL);
}
if (retval)
return retval;