2016-12-04 05:49:25

by Pan Bian

[permalink] [raw]
Subject: [PATCH 1/1] infiniband: hw: mlx4: fix improper return value

From: Pan Bian <[email protected]>

If uhw->inlen is non-zero, the value of variable err is 0 if the copy
succeeds. Then, if kzalloc() or kmalloc() returns a NULL pointer, it
will return 0 to the callers. As a result, the callers cannot detect the
errors. This patch fixes the bug, assigning "-ENOMEM" to err before
the NULL pointer checks.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=189031

Signed-off-by: Pan Bian <[email protected]>
---
drivers/infiniband/hw/mlx4/main.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index b597e82..f6c5158 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -455,6 +455,7 @@ static int mlx4_ib_query_device(struct ib_device *ibdev,
sizeof(resp.response_length);
in_mad = kzalloc(sizeof *in_mad, GFP_KERNEL);
out_mad = kmalloc(sizeof *out_mad, GFP_KERNEL);
+ err = -ENOMEM;
if (!in_mad || !out_mad)
goto out;

--
1.9.1



2016-12-04 06:15:09

by Leon Romanovsky

[permalink] [raw]
Subject: Re: [PATCH 1/1] infiniband: hw: mlx4: fix improper return value

On Sun, Dec 04, 2016 at 01:49:04PM +0800, Pan Bian wrote:
> From: Pan Bian <[email protected]>
>
> If uhw->inlen is non-zero, the value of variable err is 0 if the copy
> succeeds. Then, if kzalloc() or kmalloc() returns a NULL pointer, it
> will return 0 to the callers. As a result, the callers cannot detect the
> errors. This patch fixes the bug, assigning "-ENOMEM" to err before
> the NULL pointer checks.
>
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=189031
>
> Signed-off-by: Pan Bian <[email protected]>
> ---
> drivers/infiniband/hw/mlx4/main.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
> index b597e82..f6c5158 100644
> --- a/drivers/infiniband/hw/mlx4/main.c
> +++ b/drivers/infiniband/hw/mlx4/main.c
> @@ -455,6 +455,7 @@ static int mlx4_ib_query_device(struct ib_device *ibdev,
> sizeof(resp.response_length);
> in_mad = kzalloc(sizeof *in_mad, GFP_KERNEL);
> out_mad = kmalloc(sizeof *out_mad, GFP_KERNEL);
> + err = -ENOMEM;
> if (!in_mad || !out_mad)
> goto out;

In such case, the err initialization at the beginning of
mlx4_ib_query_device function is not necessary. Can you please remove it?

Besides that, look good.
Reviewed-by: Leon Romanovsky <[email protected]>

>
> --
> 1.9.1
>
>
> --
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