This is a note to let you know that I've just added the patch titled
ext4: fix a double free in ext4_register_li_request
to the 2.6.38-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ext4-fix-a-double-free-in-ext4_register_li_request.patch
and it can be found in the queue-2.6.38 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 46e4690bbd9a4f8d9e7c4f34e34b48f703ad47e0 Mon Sep 17 00:00:00 2001
From: Tao Ma <[email protected]>
Date: Mon, 4 Apr 2011 16:00:49 -0400
Subject: ext4: fix a double free in ext4_register_li_request
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();
Patches currently in stable-queue which might be from [email protected] are
queue-2.6.38/ext4-fix-a-double-free-in-ext4_register_li_request.patch
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