[ 26/68] pnfs-block: removing DM device maybe cause oops when call dev_remove

Greg Kroah-Hartman
2013-04-02T22:27:19Z

From: fanchaoting <fanchaoting@cn.fujitsu.com>

commit 4376c94618c26225e69e17b7c91169c45a90b292 upstream.

when pnfs block using device mapper,if umounting later,it maybe
cause oops. we apply "1 + sizeof(bl_umount_request)" memory for
msg->data, the memory maybe overflow when we do "memcpy(&dataptr
[sizeof(bl_msg)], &bl_umount_request, sizeof(bl_umount_request))",
because the size of bl_msg is more than 1 byte.

Signed-off-by: fanchaoting<fanchaoting@cn.fujitsu.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/nfs/blocklayout/blocklayoutdm.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/nfs/blocklayout/blocklayoutdm.c
+++ b/fs/nfs/blocklayout/blocklayoutdm.c
@@ -55,7 +55,8 @@ static void dev_remove(struct net *net,

bl_pipe_msg.bl_wq = &nn->bl_wq;
memset(msg, 0, sizeof(*msg));
- msg->data = kzalloc(1 + sizeof(bl_umount_request), GFP_NOFS);
+ msg->len = sizeof(bl_msg) + bl_msg.totallen;
+ msg->data = kzalloc(msg->len, GFP_NOFS);
if (!msg->data)
goto out;

@@ -66,7 +67,6 @@ static void dev_remove(struct net *net,
memcpy(msg->data, &bl_msg, sizeof(bl_msg));
dataptr = (uint8_t *) msg->data;
memcpy(&dataptr[sizeof(bl_msg)], &bl_umount_request, sizeof(bl_umount_request));
- msg->len = sizeof(bl_msg) + bl_msg.totallen;

add_wait_queue(&nn->bl_wq, &wq);
if (rpc_queue_upcall(nn->bl_device_pipe, msg) < 0) {