[patch] IB/rxe: fix error code in rxe_srq_from_init()

[patch] IB/rxe: fix error code in rxe_srq_from_init()

[Dan Carpenter]

If copy_to_user() fails then it returns the number of bytes not copied.
It would be between 1-4 here.  Later the callers dereference it leading
to an Oops.

It was sort of hard to fix this without making the code confusing so I
did a little cleanup.

Fixes: 443c15d23220 ('IB/rxe: Shared Receive Queue (SRQ) manipulation functions')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/infiniband/hw/rxe/rxe_srq.c b/drivers/infiniband/hw/rxe/rxe_srq.c
index 22c57d1..2a6e3cd 100644
--- a/drivers/infiniband/hw/rxe/rxe_srq.c
+++ b/drivers/infiniband/hw/rxe/rxe_srq.c
@@ -121,8 +121,7 @@ int rxe_srq_from_init(struct rxe_dev *rxe, struct rxe_srq *srq,
 			   srq_wqe_size);
 	if (!q) {
 		pr_warn("unable to allocate queue for srq\n");
-		err = -ENOMEM;
-		goto err1;
+		return -ENOMEM;
 	}
 
 	srq->rq.queue = q;
@@ -130,15 +129,14 @@ int rxe_srq_from_init(struct rxe_dev *rxe, struct rxe_srq *srq,
 	err = do_mmap_info(rxe, udata, false, context, q->buf,
 			   q->buf_size, &q->ip);
 	if (err)
-		goto err1;
+		return err;
 
-	if (udata && udata->outlen >= sizeof(struct mminfo) + sizeof(u32))
-		return copy_to_user(udata->outbuf + sizeof(struct mminfo),
-			&srq->srq_num, sizeof(u32));
-	else
-		return 0;
-err1:
-	return err;
+	if (udata && udata->outlen >= sizeof(struct mminfo) + sizeof(u32)) {
+		if (copy_to_user(udata->outbuf + sizeof(struct mminfo),
+				 &srq->srq_num, sizeof(u32)))
+			return -EFAULT;
+	}
+	return 0;
 }
 
 int rxe_srq_from_attr(struct rxe_dev *rxe, struct rxe_srq *srq,

Re: [patch] IB/rxe: fix error code in rxe_srq_from_init()

[Moni Shoua]

On Mon, Jun 13, 2016 at 9:53 AM, Dan Carpenter <dan.carpenter@oracle.com> wrote:
> If copy_to_user() fails then it returns the number of bytes not copied.
> It would be between 1-4 here.  Later the callers dereference it leading
> to an Oops.
>
> It was sort of hard to fix this without making the code confusing so I
> did a little cleanup.
>
> Fixes: 443c15d23220 ('IB/rxe: Shared Receive Queue (SRQ) manipulation functions')
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Thanks Dan
I'll merge it to next series

Re: [patch] IB/rxe: fix error code in rxe_srq_from_init()

[Leon Romanovsky]

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On Mon, Jun 13, 2016 at 09:53:41AM +0300, Dan Carpenter wrote:
> If copy_to_user() fails then it returns the number of bytes not copied.
> It would be between 1-4 here.  Later the callers dereference it leading
> to an Oops.
> 
> It was sort of hard to fix this without making the code confusing so I
> did a little cleanup.
> 
> Fixes: 443c15d23220 ('IB/rxe: Shared Receive Queue (SRQ) manipulation functions')
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Thanks Dan,
I applied it on topic/rxe.

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