Commit 2e21b3f1 authored Sep 23, 2010 by Tyler Hicks

eCryptfs: Clear LOOKUP_OPEN flag when creating lower file

eCryptfs was passing the LOOKUP_OPEN flag through to the lower file
system, even though ecryptfs_create() doesn't support the flag. A valid
filp for the lower filesystem could be returned in the nameidata if the
lower file system's create() function supported LOOKUP_OPEN, possibly
resulting in unencrypted writes to the lower file.

However, this is only a potential problem in filesystems (FUSE, NFS,
CIFS, CEPH, 9p) that eCryptfs isn't known to support today.

https://bugs.launchpad.net/ecryptfs/+bug/641703



Reported-by: Kevin Buhr
Cc: stable <stable@kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>

parent 48b512e6

fs/ecryptfs/inode.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -71,15 +71,19 @@ ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
		struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
		struct dentry *dentry_save;
		struct vfsmount *vfsmount_save;
		unsigned int flags_save;
		int rc;

		dentry_save = nd->path.dentry;
		vfsmount_save = nd->path.mnt;
		flags_save = nd->flags;
		nd->path.dentry = lower_dentry;
		nd->path.mnt = lower_mnt;
		nd->flags &= ~LOOKUP_OPEN;
		rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
		nd->path.dentry = dentry_save;
		nd->path.mnt = vfsmount_save;
		nd->flags = flags_save;
		return rc;
		}

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