2017-04-23 09:09:45

by Pan Bian

[permalink] [raw]
Subject: [PATCH 1/1] iw_cxgb4: check return value of alloc_skb

Function alloc_skb() will return a NULL pointer when there is no enough
memory. However, the return value of alloc_skb() is directly used
without validation in function send_fw_pass_open_req(). This patches
checks the return value of alloc_skb() against NULL.

Signed-off-by: Pan Bian <[email protected]>
---
drivers/infiniband/hw/cxgb4/cm.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index 03a1b0e..196969c 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -3800,6 +3800,8 @@ static void send_fw_pass_open_req(struct c4iw_dev *dev, struct sk_buff *skb,
int ret;

req_skb = alloc_skb(sizeof(struct fw_ofld_connection_wr), GFP_KERNEL);
+ if (!req_skb)
+ return;
req = (struct fw_ofld_connection_wr *)__skb_put(req_skb, sizeof(*req));
memset(req, 0, sizeof(*req));
req->op_compl = htonl(WR_OP_V(FW_OFLD_CONNECTION_WR) | FW_WR_COMPL_F);
--
1.9.1



2017-04-23 16:51:39

by Leon Romanovsky

[permalink] [raw]
Subject: Re: [PATCH 1/1] iw_cxgb4: check return value of alloc_skb

On Sun, Apr 23, 2017 at 05:09:11PM +0800, Pan Bian wrote:
> Function alloc_skb() will return a NULL pointer when there is no enough
> memory. However, the return value of alloc_skb() is directly used
> without validation in function send_fw_pass_open_req(). This patches
> checks the return value of alloc_skb() against NULL.
>
> Signed-off-by: Pan Bian <[email protected]>
> ---
> drivers/infiniband/hw/cxgb4/cm.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
> index 03a1b0e..196969c 100644
> --- a/drivers/infiniband/hw/cxgb4/cm.c
> +++ b/drivers/infiniband/hw/cxgb4/cm.c
> @@ -3800,6 +3800,8 @@ static void send_fw_pass_open_req(struct c4iw_dev *dev, struct sk_buff *skb,
> int ret;
>
> req_skb = alloc_skb(sizeof(struct fw_ofld_connection_wr), GFP_KERNEL);
> + if (!req_skb)
> + return;

The check is right, but the outcome is unpredictable. The function
send_fw_pass_open_req() doesn't return any error and caller doesn't check
it.

> req = (struct fw_ofld_connection_wr *)__skb_put(req_skb, sizeof(*req));
> memset(req, 0, sizeof(*req));
> req->op_compl = htonl(WR_OP_V(FW_OFLD_CONNECTION_WR) | FW_WR_COMPL_F);
> --
> 1.9.1
>
>

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2017-04-28 17:10:52

by Doug Ledford

[permalink] [raw]
Subject: Re: [PATCH 1/1] iw_cxgb4: check return value of alloc_skb

On Sun, 2017-04-23 at 17:09 +0800, Pan Bian wrote:
> Function alloc_skb() will return a NULL pointer when there is no
> enough
> memory. However, the return value of alloc_skb() is directly used
> without validation in function send_fw_pass_open_req(). This patches
> checks the return value of alloc_skb() against NULL.
>
> Signed-off-by: Pan Bian <[email protected]>

Thanks, applied.

--
Doug Ledford <[email protected]>
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