From: Jan Kara Date: Tue, 25 Mar 2014 20:37:09 +0000 (+0100) Subject: fs: Avoid userspace mounting anon_inodefs filesystem X-Git-Url: http://pileus.org/git/?p=~andy%2Flinux;a=commitdiff_plain;h=d6f2589ad561aa5fa39f347eca6942668b7560a1 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 Signed-off-by: Jan Kara Signed-off-by: Linus Torvalds --- diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c index 24084732b1d..4b4543b8b89 100644 --- 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);