[PATCH 3.18 19/29] net/mlx5: Fix incorrect raw command length parsing

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alex Vesker <valex@mellanox.com>

[ Upstream commit 603b7bcff824740500ddfa001d7a7168b0b38542 ]

The NULL character was not set correctly for the string containing
the command length, this caused failures reading the output of the
command due to a random length. The fix is to initialize the output
length string.

Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Signed-off-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/mellanox/mlx5/core/cmd.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
@@ -933,7 +933,7 @@ static ssize_t outlen_write(struct file
 {
 	struct mlx5_core_dev *dev = filp->private_data;
 	struct mlx5_cmd_debug *dbg = &dev->cmd.dbg;
-	char outlen_str[8];
+	char outlen_str[8] = {0};
 	int outlen;
 	void *ptr;
 	int err;
@@ -948,8 +948,6 @@ static ssize_t outlen_write(struct file
 	if (copy_from_user(outlen_str, buf, count))
 		return -EFAULT;
 
-	outlen_str[7] = 0;
-
 	err = sscanf(outlen_str, "%d", &outlen);
 	if (err < 0)
 		return err;