2007-08-01 14:58:55

by Michael Halcrow

[permalink] [raw]
Subject: Re: [PATCH 2.6.23-rc1] eCryptfs: fix lookup error for special files

On Wed, Aug 01, 2007 at 10:01:14PM +0900, Ryusuke Konishi wrote:
> When ecryptfs_lookup() is called against special files, eCryptfs
> generates the following errors because it tries to treat them like
> regular eCryptfs files.
>
> Error opening lower file for lower_dentry [0xffff810233a6f150], lower_mnt [0xffff810235bb4c80], and flags
> [0x8000]
> Error opening lower_file to read header region
> Error attempting to read the [user.ecryptfs] xattr from the lower file; return value = [-95]
> Valid metadata not found in header region or xattr region; treating file as unencrypted
>
> For instance, the problem can be reproduced by the steps below.
>
> # mkdir /root/crypt /mnt/crypt
> # mount -t ecryptfs /root/crypt /mnt/crypt
> # mknod /mnt/crypt/c0 c 0 0
> # umount /mnt/crypt
> # mount -t ecryptfs /root/crypt /mnt/crypt
> # ls -l /mnt/crypt
>
> This patch fixes it by adding a check similar to directories and
> symlinks.
>
> Signed-off-by: Ryusuke Konishi <[email protected]>

Acked-by: Michael Halcrow <[email protected]>

> ---
> fs/ecryptfs/inode.c | 4 ++++
> 1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
> index 0a50942..131954b 100644
> --- a/fs/ecryptfs/inode.c
> +++ b/fs/ecryptfs/inode.c
> @@ -353,6 +353,10 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
> ecryptfs_printk(KERN_DEBUG, "Is a symlink; returning\n");
> goto out;
> }
> + if (special_file(lower_inode->i_mode)) {
> + ecryptfs_printk(KERN_DEBUG, "Is a special file; returning\n");
> + goto out;
> + }
> if (!nd) {
> ecryptfs_printk(KERN_DEBUG, "We have a NULL nd, just leave"
> "as we *think* we are about to unlink\n");