fs: Avoid userspace mounting anon_inodefs filesystem

anon_inodefs filesystem is a kernel internal filesystem userspace shouldn't mess with. Remove registration of it so userspace cannot even try to mount it (which would fail anyway because the filesystem is MS_NOUSER). This fixes an oops triggered by trinity when it tried mounting anon_inodefs which overwrote anon_inode_inode pointer while other CPU has been in anon_inode_getfile() between ihold() and d_instantiate(). Thus effectively creating dentry pointing to an inode without holding a reference to it. Reported-by: Sasha Levin <[email protected]> Signed-off-by: Jan Kara <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
codyps · Mar 26, 2014 · d6f2589 · d6f2589
1 parent 632b06a
commit d6f2589
Showing 1 changed file with 0 additions and 3 deletions.
diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
@@ -177,9 +177,6 @@ static int __init anon_inode_init(void)
 {
 	int error;
 
-	error = register_filesystem(&anon_inode_fs_type);
-	if (error)
-		goto err_exit;
 	anon_inode_mnt = kern_mount(&anon_inode_fs_type);
 	if (IS_ERR(anon_inode_mnt)) {
 		error = PTR_ERR(anon_inode_mnt);