Patch "IB/core: Fix use after free in send_leave function" has been added to the 4.7-stable tree

Patch "IB/core: Fix use after free in send_leave function" has been added to the 4.7-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    IB/core: Fix use after free in send_leave function

to the 4.7-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:
     ib-core-fix-use-after-free-in-send_leave-function.patch
and it can be found in the queue-4.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 68c6bcdd8bd00394c234b915ab9b97c74104130c Mon Sep 17 00:00:00 2001
From: Erez Shitrit <erezsh@mellanox.com>
Date: Sun, 28 Aug 2016 10:58:30 +0300
Subject: IB/core: Fix use after free in send_leave function

From: Erez Shitrit <erezsh@mellanox.com>

commit 68c6bcdd8bd00394c234b915ab9b97c74104130c upstream.

The function send_leave sets the member: group->query_id
(group->query_id = ret) after calling the sa_query, but leave_handler
can be executed before the setting and it might delete the group object,
and will get a memory corruption.

Additionally, this patch gets rid of group->query_id variable which is
not used.

Fixes: faec2f7b96b5 ('IB/sa: Track multicast join/leave requests')
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/infiniband/core/multicast.c |   13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

--- a/drivers/infiniband/core/multicast.c
+++ b/drivers/infiniband/core/multicast.c
@@ -118,7 +118,6 @@ struct mcast_group {
 	atomic_t		refcount;
 	enum mcast_group_state	state;
 	struct ib_sa_query	*query;
-	int			query_id;
 	u16			pkey_index;
 	u8			leave_state;
 	int			retries;
@@ -352,11 +351,7 @@ static int send_join(struct mcast_group
 				       member->multicast.comp_mask,
 				       3000, GFP_KERNEL, join_handler, group,
 				       &group->query);
-	if (ret >= 0) {
-		group->query_id = ret;
-		ret = 0;
-	}
-	return ret;
+	return (ret > 0) ? 0 : ret;
 }
 
 static int send_leave(struct mcast_group *group, u8 leave_state)
@@ -376,11 +371,7 @@ static int send_leave(struct mcast_group
 				       IB_SA_MCMEMBER_REC_JOIN_STATE,
 				       3000, GFP_KERNEL, leave_handler,
 				       group, &group->query);
-	if (ret >= 0) {
-		group->query_id = ret;
-		ret = 0;
-	}
-	return ret;
+	return (ret > 0) ? 0 : ret;
 }
 
 static void join_group(struct mcast_group *group, struct mcast_member *member,


Patches currently in stable-queue which might be from erezsh@mellanox.com are

queue-4.7/ib-ipoib-fix-memory-corruption-in-ipoib-cm-mode-connect-flow.patch
queue-4.7/ib-core-fix-use-after-free-in-send_leave-function.patch