2.6.38-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Tao Ma <[email protected]>

commit 46e4690bbd9a4f8d9e7c4f34e34b48f703ad47e0 upstream.

In ext4_register_li_request, we malloc a ext4_li_request and
inserts it into ext4_li_info->li_request_list. In case of any
error later, we free it in the end.  But if we have some error
in ext4_run_lazyinit_thread, the whole li_request_list will be
dropped and freed in it. So we will double free this ext4_li_request.

This patch just sets elr to NULL after it is inserted to the list
so that the latter kfree won't double free it.

Signed-off-by: Tao Ma <[email protected]>
Reviewed-by: Lukas Czerner <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 fs/ext4/super.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2978,6 +2978,12 @@ static int ext4_register_li_request(stru
        mutex_unlock(&ext4_li_info->li_list_mtx);
 
        sbi->s_li_request = elr;
+       /*
+        * set elr to NULL here since it has been inserted to
+        * the request_list and the removal and free of it is
+        * handled by ext4_clear_request_list from now on.
+        */
+       elr = NULL;
 
        if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
                ret = ext4_run_lazyinit_thread();


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