diff options
| author | Miklos Szeredi <miklos@szeredi.hu> | 2005-07-07 17:57:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-07-07 18:23:51 -0700 |
| commit | 202322e6f7cd12e82b5ff0fa92bbdf517fcf0947 (patch) | |
| tree | 82c1f7b4b97d5b31654157a8f427a5c8d546504f /fs | |
| parent | 6f50142e4b092a469920a0008fc23121c3d99f2f (diff) | |
[PATCH] namespace.c: fix mnt_namespace clearing
This patch clears mnt_namespace on unmount.
Not clearing mnt_namespace has two effects:
1) It is possible to attach a new mount to a detached mount,
because check_mnt() returns true.
This means, that when no other references to the detached mount
remain, it still can't be freed. This causes a resource leak,
and possibly un-removable modules.
2) If mnt_namespace is dereferenced (only in mark_mounts_for_expiry())
after the namspace has been freed, it can cause an Oops, memory
corruption, etc.
1) has been tested before and after the patch, 2) is only speculation.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/namespace.c | 8 |
1 files changed, 1 insertions, 7 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 208c079e9fdb..a0d0ef1f1a48 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -345,6 +345,7 @@ static void umount_tree(struct vfsmount *mnt) for (p = mnt; p; p = next_mnt(p, mnt)) { list_del(&p->mnt_list); list_add(&p->mnt_list, &kill); + p->mnt_namespace = NULL; } while (!list_empty(&kill)) { @@ -1449,15 +1450,8 @@ void __init mnt_init(unsigned long mempages) void __put_namespace(struct namespace *namespace) { - struct vfsmount *mnt; - down_write(&namespace->sem); spin_lock(&vfsmount_lock); - - list_for_each_entry(mnt, &namespace->list, mnt_list) { - mnt->mnt_namespace = NULL; - } - umount_tree(namespace->root); spin_unlock(&vfsmount_lock); up_write(&namespace->sem); |