[PATCH] fix filp_cachep memory corruption

["J. R. Okajima" <hooanon05@yahoo.co.jp>]

commit e1ddf5b0dd3e8234581c78c3cadd6e2adfe6e2d4
Author: J. R. Okajima <hooanon05@yahoo.co.jp>
Date:   Thu Feb 3 03:38:12 2011 +0900

    fix filp_cachep memory corruption
    
    By the commit
    	31e6b01 2011-01-07 fs: rcu-walk for path lookup
    the condition "-ESTALE && !LOOKUP_REVAL" is added to "goto reval" in
    do_filp_open(), and it lookup again with LOOKUP_REVAL _after_
    release_open_intent(). Since release_open_intent() is called by
    do_last() and finish_open() too, add the same condition to all of them.
    
    Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>

diff --git a/fs/namei.c b/fs/namei.c
index 084be4d..1f62d6a 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2269,7 +2269,8 @@ static struct file *finish_open(struct nameidata *nd,
 	return filp;
 
 exit:
-	if (!IS_ERR(nd->intent.open.file))
+	if (!(error == -ESTALE && !(nd->flags & LOOKUP_REVAL))
+	    && !IS_ERR(nd->intent.open.file))
 		release_open_intent(nd);
 	path_put(&nd->path);
 	return ERR_PTR(error);
@@ -2393,7 +2394,8 @@ exit_mutex_unlock:
 exit_dput:
 	path_put_conditional(path, nd);
 exit:
-	if (!IS_ERR(nd->intent.open.file))
+	if (!(error == -ESTALE && !(nd->flags & LOOKUP_REVAL))
+	    && !IS_ERR(nd->intent.open.file))
 		release_open_intent(nd);
 	path_put(&nd->path);
 	return ERR_PTR(error);
@@ -2564,7 +2566,8 @@ exit_dput:
 out_path:
 	path_put(&nd.path);
 out_filp:
-	if (!IS_ERR(nd.intent.open.file))
+	if (!(error == -ESTALE && !(flags & LOOKUP_REVAL))
+	    && !IS_ERR(nd.intent.open.file))
 		release_open_intent(&nd);
 	filp = ERR_PTR(error);
 	goto out;