[PATCH 4.4 081/158] eCryptfs: fix a couple type promotion bugs

Greg Kroah-Hartman
2019-08-02T09:40:13Z

From: Dan Carpenter <dan.carpenter@oracle.com>

commit 0bdf8a8245fdea6f075a5fede833a5fcf1b3466c upstream.

ECRYPTFS_SIZE_AND_MARKER_BYTES is type size_t, so if "rc" is negative
that gets type promoted to a high positive value and treated as success.

Fixes: 778aeb42a708 ("eCryptfs: Cleanup and optimize ecryptfs_lookup_interpose()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[tyhicks: Use "if/else if" rather than "if/if"]
Cc: stable@vger.kernel.org
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/ecryptfs/crypto.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1041,8 +1041,10 @@ int ecryptfs_read_and_validate_header_re

rc = ecryptfs_read_lower(file_size, 0, ECRYPTFS_SIZE_AND_MARKER_BYTES,
inode);
- if (rc < ECRYPTFS_SIZE_AND_MARKER_BYTES)
- return rc >= 0 ? -EINVAL : rc;
+ if (rc < 0)
+ return rc;
+ else if (rc < ECRYPTFS_SIZE_AND_MARKER_BYTES)
+ return -EINVAL;
rc = ecryptfs_validate_marker(marker);
if (!rc)
ecryptfs_i_size_init(file_size, inode);
@@ -1400,8 +1402,10 @@ int ecryptfs_read_and_validate_xattr_reg
rc = ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry),
ECRYPTFS_XATTR_NAME, file_size,
ECRYPTFS_SIZE_AND_MARKER_BYTES);
- if (rc < ECRYPTFS_SIZE_AND_MARKER_BYTES)
- return rc >= 0 ? -EINVAL : rc;
+ if (rc < 0)
+ return rc;
+ else if (rc < ECRYPTFS_SIZE_AND_MARKER_BYTES)
+ return -EINVAL;
rc = ecryptfs_validate_marker(marker);
if (!rc)
ecryptfs_i_size_init(file_size, inode);