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authorTyler Hicks <tyhicks@canonical.com>2011-11-05 13:45:08 -0400
committerTyler Hicks <tyhicks@canonical.com>2012-02-16 16:06:21 -0600
commit4a26620df451ad46151ad21d711ed43e963c004e (patch)
treebf035ea6a656b3e19fe93bf37991632cad96d971 /fs/ecryptfs/super.c
parentc38e23456278e967f094b08247ffc3711b1029b2 (diff)
downloadlinux-4a26620df451ad46151ad21d711ed43e963c004e.tar.bz2
eCryptfs: Improve statfs reporting
statfs() calls on eCryptfs files returned the wrong filesystem type and, when using filename encryption, the wrong maximum filename length. If mount-wide filename encryption is enabled, the cipher block size and the lower filesystem's max filename length will determine the max eCryptfs filename length. Pre-tested, known good lengths are used when the lower filesystem's namelen is 255 and a cipher with 8 or 16 byte block sizes is used. In other, less common cases, we fall back to a safe rounded-down estimate when determining the eCryptfs namelen. https://launchpad.net/bugs/885744 Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Reported-by: Kees Cook <keescook@chromium.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: John Johansen <john.johansen@canonical.com>
Diffstat (limited to 'fs/ecryptfs/super.c')
-rw-r--r--fs/ecryptfs/super.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/fs/ecryptfs/super.c b/fs/ecryptfs/super.c
index 9df7fd6e0c39..cf152823bbf4 100644
--- a/fs/ecryptfs/super.c
+++ b/fs/ecryptfs/super.c
@@ -30,6 +30,8 @@
#include <linux/seq_file.h>
#include <linux/file.h>
#include <linux/crypto.h>
+#include <linux/statfs.h>
+#include <linux/magic.h>
#include "ecryptfs_kernel.h"
struct kmem_cache *ecryptfs_inode_info_cache;
@@ -102,10 +104,20 @@ static void ecryptfs_destroy_inode(struct inode *inode)
static int ecryptfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+ int rc;
if (!lower_dentry->d_sb->s_op->statfs)
return -ENOSYS;
- return lower_dentry->d_sb->s_op->statfs(lower_dentry, buf);
+
+ rc = lower_dentry->d_sb->s_op->statfs(lower_dentry, buf);
+ if (rc)
+ return rc;
+
+ buf->f_type = ECRYPTFS_SUPER_MAGIC;
+ rc = ecryptfs_set_f_namelen(&buf->f_namelen, buf->f_namelen,
+ &ecryptfs_superblock_to_private(dentry->d_sb)->mount_crypt_stat);
+
+ return rc;
}
/**