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Commit f0d62aec authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

userns: Rename id_map_mutex to userns_state_mutex 



Generalize id_map_mutex so it can be used for more state of a user namespace.

Cc: stable@vger.kernel.org
Reviewed-by: default avatarAndy Lutomirski <luto@amacapital.net>
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent f95d7918

kernel/user_namespace.c

+6 −8
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/fs_struct.h>



static struct kmem_cache *user_ns_cachep __read_mostly;

static DEFINE_MUTEX(userns_state_mutex);



static bool new_idmap_permitted(const struct file *file,

				struct user_namespace *ns, int cap_setid,
@@ -583,9 +584,6 @@ static bool mappings_overlap(struct uid_gid_map *new_map, 
	return false;

}





static DEFINE_MUTEX(id_map_mutex);



static ssize_t map_write(struct file *file, const char __user *buf,

			 size_t count, loff_t *ppos,

			 int cap_setid,
@@ -602,7 +600,7 @@ static ssize_t map_write(struct file *file, const char __user *buf, 
	ssize_t ret = -EINVAL;



	/*

	 * The id_map_mutex serializes all writes to any given map.

	 * The userns_state_mutex serializes all writes to any given map.

	 *

	 * Any map is only ever written once.

	 *
@@ -620,7 +618,7 @@ static ssize_t map_write(struct file *file, const char __user *buf, 
	 * order and smp_rmb() is guaranteed that we don't have crazy

	 * architectures returning stale data.

	 */

	mutex_lock(&id_map_mutex);

	mutex_lock(&userns_state_mutex);



	ret = -EPERM;

	/* Only allow one successful write to the map */
@@ -750,7 +748,7 @@ static ssize_t map_write(struct file *file, const char __user *buf, 
	*ppos = count;

	ret = count;

out:

	mutex_unlock(&id_map_mutex);

	mutex_unlock(&userns_state_mutex);

	if (page)

		free_page(page);

	return ret;
@@ -845,12 +843,12 @@ bool userns_may_setgroups(const struct user_namespace *ns) 
{

	bool allowed;



	mutex_lock(&id_map_mutex);

	mutex_lock(&userns_state_mutex);

	/* It is not safe to use setgroups until a gid mapping in

	 * the user namespace has been established.

	 */

	allowed = ns->gid_map.nr_extents != 0;

	mutex_unlock(&id_map_mutex);

	mutex_unlock(&userns_state_mutex);



	return allowed;

}