eCryptfs: Regression in unencrypted filename symlinks

The addition of filename encryption caused a regression in unencrypted
filename symlink support.  ecryptfs_copy_filename() is used when dealing
with unencrypted filenames and it reported that the new, copied filename
was a character longer than it should have been.

This caused the return value of readlink() to count the NULL byte of the
symlink target.  Most applications don't care about the extra NULL byte,
but a version control system (bzr) helped in discovering the bug.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index c01e043670e21300808dcd5d58e77f19bfccd076..f6caeb1d110621e7c24c1ab0b714f5774e333a93 100644 (file)
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1716,7 +1716,7 @@ static int ecryptfs_copy_filename(char **copied_name, size_t *copied_name_size,
 {
        int rc = 0;
 
-       (*copied_name) = kmalloc((name_size + 2), GFP_KERNEL);
+       (*copied_name) = kmalloc((name_size + 1), GFP_KERNEL);
        if (!(*copied_name)) {
                rc = -ENOMEM;
                goto out;
@@ -1726,7 +1726,7 @@ static int ecryptfs_copy_filename(char **copied_name, size_t *copied_name_size,
                                                 * in printing out the
                                                 * string in debug
                                                 * messages */
-       (*copied_name_size) = (name_size + 1);
+       (*copied_name_size) = name_size;
 out:
        return rc;
 }