Unverified Commit e243e3f9 authored by Christian Brauner's avatar Christian Brauner Committed by Christian Brauner (Microsoft)
Browse files

fs: move should_remove_suid() 



Move the helper from inode.c to attr.c. This keeps the the core of the
set{g,u}id stripping logic in one place when we add follow-up changes.
It is the better place anyway, since should_remove_suid() returns
ATTR_KILL_S{G,U}ID flags.

Reviewed-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarChristian Brauner (Microsoft) <brauner@kernel.org>
parent 11c2a870

fs/attr.c

+29 −0
Original line number Diff line number Diff line
@@ -20,6 +20,35 @@ 


#include "internal.h"



/*

 * The logic we want is

 *

 *	if suid or (sgid and xgrp)

 *		remove privs

 */

int should_remove_suid(struct dentry *dentry)

{

	umode_t mode = d_inode(dentry)->i_mode;

	int kill = 0;



	/* suid always must be killed */

	if (unlikely(mode & S_ISUID))

		kill = ATTR_KILL_SUID;



	/*

	 * sgid without any exec bits is just a mandatory locking mark; leave

	 * it alone.  If some exec bits are set, it's a real sgid; kill it.

	 */

	if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))

		kill |= ATTR_KILL_SGID;



	if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode)))

		return kill;



	return 0;

}

EXPORT_SYMBOL(should_remove_suid);



/**

 * chown_ok - verify permissions to chown inode

 * @mnt_userns:	user namespace of the mount @inode was found from

fs/inode.c

+0 −29
Original line number Diff line number Diff line
@@ -1948,35 +1948,6 @@ void touch_atime(const struct path *path) 
}

EXPORT_SYMBOL(touch_atime);



/*

 * The logic we want is

 *

 *	if suid or (sgid and xgrp)

 *		remove privs

 */

int should_remove_suid(struct dentry *dentry)

{

	umode_t mode = d_inode(dentry)->i_mode;

	int kill = 0;



	/* suid always must be killed */

	if (unlikely(mode & S_ISUID))

		kill = ATTR_KILL_SUID;



	/*

	 * sgid without any exec bits is just a mandatory locking mark; leave

	 * it alone.  If some exec bits are set, it's a real sgid; kill it.

	 */

	if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))

		kill |= ATTR_KILL_SGID;



	if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode)))

		return kill;



	return 0;

}

EXPORT_SYMBOL(should_remove_suid);



/*

 * Return mask of changes for notify_change() that need to be done as a

 * response to write or truncate. Return 0 if nothing has to be changed.