fix refcounting of nsproxy object when unshared

4e71e474 · Cedric Le Goater <[email protected]> · 2007-06-23 17:16:25 -07:00

When a namespace is unshared, a refcount on the previous nsproxy is
abusively taken, leading to a memory leak of nsproxy objects.

Signed-off-by: Cedric Le Goater <[email protected]>
Cc: Badari Pulavarty <[email protected]>
Cc: Herbert Poetzl <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: 4e71e474c784dc274f28ec8bb22a5dbabc6dc7c5
Parents: 6d79af70

Changes

1 files changed · +2 −8

File	Status	Add	Del	Content
kernel/nsproxy.c	modified	+2	−8	View file

kernel/nsproxy.c

View file

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 1bc4b55..9e83b58 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -145,13 +145,11 @@ void free_nsproxy(struct nsproxy *ns)
 
 /*
  * Called from unshare. Unshare all the namespaces part of nsproxy.
- * On sucess, returns the new nsproxy and a reference to old nsproxy
- * to make sure it stays around.
+ * On success, returns the new nsproxy.
  */
 int unshare_nsproxy_namespaces(unsigned long unshare_flags,
 		struct nsproxy **new_nsp, struct fs_struct *new_fs)
 {
-	struct nsproxy *old_ns = current->nsproxy;
 	int err = 0;
 
 	if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))
@@ -170,13 +168,9 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags,
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	get_nsproxy(old_ns);
-
 	*new_nsp = create_new_namespaces(unshare_flags, current,
 				new_fs ? new_fs : current->fs);
-	if (IS_ERR(*new_nsp)) {
+	if (IS_ERR(*new_nsp))
 		err = PTR_ERR(*new_nsp);
-		put_nsproxy(old_ns);
-	}
 	return err;
 }