Revert "fs: ocfs2: fix possible null-pointer dereferences in ocfs2_xa_prepare_entry()"

This reverts commit 56e94ea132bb5c2c1d0b60a6aeb34dcb7d71a53d.

Commit 56e94ea132bb ("fs: ocfs2: fix possible null-pointer dereferences
in ocfs2_xa_prepare_entry()") introduces a regression that fail to
create directory with mount option user_xattr and acl.  Actually the
reported NULL pointer dereference case can be correctly handled by
loc->xl_ops->xlo_add_entry(), so revert it.

Link: http://lkml.kernel.org/r/1573624916-83825-1-git-send-email-joseph.qi@linux.alibaba.com
Fixes: 56e94ea132bb ("fs: ocfs2: fix possible null-pointer dereferences in ocfs2_xa_prepare_entry()")
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reported-by: Thomas Voegtle <tv@lio96.de>
Acked-by: Changwei Ge <gechangwei@live.cn>
Cc: Jia-Ju Bai <baijiaju1990@gmail.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index d8507972ee135f95a4ff9bcc696cc456c2977ee5..90c830e3758e2dea9af508efed08b48a8509553f 100644 (file)
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -1490,6 +1490,18 @@ static int ocfs2_xa_check_space(struct ocfs2_xa_loc *loc,
        return loc->xl_ops->xlo_check_space(loc, xi);
 }
 
+static void ocfs2_xa_add_entry(struct ocfs2_xa_loc *loc, u32 name_hash)
+{
+       loc->xl_ops->xlo_add_entry(loc, name_hash);
+       loc->xl_entry->xe_name_hash = cpu_to_le32(name_hash);
+       /*
+        * We can't leave the new entry's xe_name_offset at zero or
+        * add_namevalue() will go nuts.  We set it to the size of our
+        * storage so that it can never be less than any other entry.
+        */
+       loc->xl_entry->xe_name_offset = cpu_to_le16(loc->xl_size);
+}
+
 static void ocfs2_xa_add_namevalue(struct ocfs2_xa_loc *loc,
                                   struct ocfs2_xattr_info *xi)
 {
@@ -2121,31 +2133,29 @@ static int ocfs2_xa_prepare_entry(struct ocfs2_xa_loc *loc,
        if (rc)
                goto out;
 
-       if (!loc->xl_entry) {
-               rc = -EINVAL;
-               goto out;
-       }
-
-       if (ocfs2_xa_can_reuse_entry(loc, xi)) {
-               orig_value_size = loc->xl_entry->xe_value_size;
-               rc = ocfs2_xa_reuse_entry(loc, xi, ctxt);
-               if (rc)
-                       goto out;
-               goto alloc_value;
-       }
+       if (loc->xl_entry) {
+               if (ocfs2_xa_can_reuse_entry(loc, xi)) {
+                       orig_value_size = loc->xl_entry->xe_value_size;
+                       rc = ocfs2_xa_reuse_entry(loc, xi, ctxt);
+                       if (rc)
+                               goto out;
+                       goto alloc_value;
+               }
 
-       if (!ocfs2_xattr_is_local(loc->xl_entry)) {
-               orig_clusters = ocfs2_xa_value_clusters(loc);
-               rc = ocfs2_xa_value_truncate(loc, 0, ctxt);
-               if (rc) {
-                       mlog_errno(rc);
-                       ocfs2_xa_cleanup_value_truncate(loc,
-                                                       "overwriting",
-                                                       orig_clusters);
-                       goto out;
+               if (!ocfs2_xattr_is_local(loc->xl_entry)) {
+                       orig_clusters = ocfs2_xa_value_clusters(loc);
+                       rc = ocfs2_xa_value_truncate(loc, 0, ctxt);
+                       if (rc) {
+                               mlog_errno(rc);
+                               ocfs2_xa_cleanup_value_truncate(loc,
+                                                               "overwriting",
+                                                               orig_clusters);
+                               goto out;
+                       }
                }
-       }
-       ocfs2_xa_wipe_namevalue(loc);
+               ocfs2_xa_wipe_namevalue(loc);
+       } else
+               ocfs2_xa_add_entry(loc, name_hash);
 
        /*
         * If we get here, we have a blank entry.  Fill it.  We grow our