[PATCH net] net/mlx5: Fix uninitialized variable bug in outlen_write()

[PATCH net] net/mlx5: Fix uninitialized variable bug in outlen_write()

[YueHaibing]

If sscanf() return 0, outlen is uninitialized and used in kzalloc(),
this is unexpected. We should return -EINVAL if the string is invalid.

Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
index 2e0d59ca62b5..cfb1e9f18a6c 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
@@ -1508,8 +1508,8 @@ static ssize_t outlen_write(struct file *filp, const char __user *buf,
 		return -EFAULT;
 
 	err = sscanf(outlen_str, "%d", &outlen);
-	if (err < 0)
-		return err;
+	if (err != 1)
+		return -EINVAL;
 
 	ptr = kzalloc(outlen, GFP_KERNEL);
 	if (!ptr)
-- 
2.17.1

Re: [PATCH net] net/mlx5: Fix uninitialized variable bug in outlen_write()

[Leon Romanovsky]

On Mon, Nov 21, 2022 at 07:22:04PM +0800, YueHaibing wrote:
> If sscanf() return 0, outlen is uninitialized and used in kzalloc(),
> this is unexpected. We should return -EINVAL if the string is invalid.
> 
> Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
> ---
>  drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

Re: [PATCH net] net/mlx5: Fix uninitialized variable bug in outlen_write()

[Saeed Mahameed]

On 21 Nov 19:22, YueHaibing wrote:
>If sscanf() return 0, outlen is uninitialized and used in kzalloc(),
>this is unexpected. We should return -EINVAL if the string is invalid.
>
>Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
>Signed-off-by: YueHaibing <yuehaibing@huawei.com>
>

applied to net-mlx5, thanks !