f2fs crypto: fix corrupted symlink in encrypted case

commit c90e09f7fb498f81cd4e8bb6460d3a26ccebeca3 upstream.

In the encrypted symlink case, we should check its corrupted symname after
decrypting it.
Otherwise, we can report -ENOENT incorrectly, if encrypted symname starts with
'\0'.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 6f944e5eb76eb71ab89d56e1cab7c6526ea443a5..7e9e3876966096bb635f1356fd32105929b85cbf 100644 (file)
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -980,12 +980,6 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry,
        }
        memcpy(cstr.name, sd->encrypted_path, cstr.len);
 
-       /* this is broken symlink case */
-       if (unlikely(cstr.name[0] == 0)) {
-               res = -ENOENT;
-               goto errout;
-       }
-
        if ((cstr.len + sizeof(struct f2fs_encrypted_symlink_data) - 1) >
                                                                max_size) {
                /* Symlink data on the disk is corrupted */
@@ -1002,6 +996,12 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry,
 
        kfree(cstr.name);
 
+       /* this is broken symlink case */
+       if (unlikely(pstr.name[0] == 0)) {
+               res = -ENOENT;
+               goto errout;
+       }
+
        paddr = pstr.name;
 
        /* Null-terminate the name */