2019-07-26 17:56:29

by Jia-Ju Bai

Subject: [PATCH] net: rds: Fix possible null-pointer dereferences in rds_rdma_cm_event_handler_cmn()

In rds_rdma_cm_event_handler_cmn(), there are some if statements to
check whether conn is NULL, such as on lines 65, 96 and 112.
But conn is not checked before being used on line 108:
trans->cm_connect_complete(conn, event);
and on lines 140-143:
rdsdebug("DISCONNECT event - dropping connection "
"%pI6c->%pI6c\n", &conn->c_laddr,
&conn->c_faddr);
rds_conn_drop(conn);

Thus, possible null-pointer dereferences may occur.

To fix these bugs, conn is checked before being used.

These bugs are found by a static analysis tool STCheck written by us.

Signed-off-by: Jia-Ju Bai <[email protected]>
---
net/rds/rdma_transport.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/rds/rdma_transport.c b/net/rds/rdma_transport.c
index ff74c4bbb9fc..9986d6065c4d 100644
--- a/net/rds/rdma_transport.c
+++ b/net/rds/rdma_transport.c
@@ -105,7 +105,8 @@ static int rds_rdma_cm_event_handler_cmn(struct rdma_cm_id *cm_id,
break;

case RDMA_CM_EVENT_ESTABLISHED:
- trans->cm_connect_complete(conn, event);
+ if (conn)
+ trans->cm_connect_complete(conn, event);
break;

case RDMA_CM_EVENT_REJECTED:
@@ -137,6 +138,8 @@ static int rds_rdma_cm_event_handler_cmn(struct rdma_cm_id *cm_id,
break;

case RDMA_CM_EVENT_DISCONNECTED:
+ if (!conn)
+ break;
rdsdebug("DISCONNECT event - dropping connection "
"%pI6c->%pI6c\n", &conn->c_laddr,
&conn->c_faddr);
--
2.17.0

2019-07-27 21:00:18

by David Miller

Subject: Re: [PATCH] net: rds: Fix possible null-pointer dereferences in rds_rdma_cm_event_handler_cmn()

From: Jia-Ju Bai <[email protected]>
Date: Fri, 26 Jul 2019 22:17:05 +0800

> In rds_rdma_cm_event_handler_cmn(), there are some if statements to
> check whether conn is NULL, such as on lines 65, 96 and 112.
> But conn is not checked before being used on line 108:
> trans->cm_connect_complete(conn, event);
> and on lines 140-143:
> rdsdebug("DISCONNECT event - dropping connection "
> "%pI6c->%pI6c\n", &conn->c_laddr,
> &conn->c_faddr);
> rds_conn_drop(conn);
>
> Thus, possible null-pointer dereferences may occur.
>
> To fix these bugs, conn is checked before being used.
>
> These bugs are found by a static analysis tool STCheck written by us.
>
> Signed-off-by: Jia-Ju Bai <[email protected]>

Applied.