eCryptfs: fix a couple type promotion bugs

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>

1 files changed, 8 insertions, 4 deletions

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 4dd842f72846..708f931c36f1 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1018,8 +1018,10 @@ int ecryptfs_read_and_validate_header_region(struct inode *inode)
 
         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);
@@ -1381,8 +1383,10 @@ int ecryptfs_read_and_validate_xattr_region(struct dentry *dentry,
                                      ecryptfs_inode_to_lower(inode),
                                      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);