Received-SPF: pass (google.com: best guess record for domain of linux-wireless-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Jia-Ju Bai <baijiaju1990@gmail.com>
To:     kvalo@codeaurora.org, davem@davemloft.net
Cc:     linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [PATCH] ath6kl: Fix a possible null-pointer dereference in ath6kl_htc_mbox_create()
Date:   Mon, 29 Jul 2019 11:03:05 +0800
Message-Id: <20190729030305.18410-1-baijiaju1990@gmail.com>
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

In ath6kl_htc_mbox_create(), when kzalloc() on line 2855 fails,
target->dev is assigned to NULL, and ath6kl_htc_mbox_cleanup(target) is
called on line 2885.

In ath6kl_htc_mbox_cleanup(), target->dev is used on line 2895:
    ath6kl_hif_cleanup_scatter(target->dev->ar);

Thus, a null-pointer dereference may occur.

To fix this bug, kfree(target) is called and NULL is returned when
kzalloc() on line 2855 fails.

This bug is found by a static analysis tool STCheck written by us.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
 drivers/net/wireless/ath/ath6kl/htc_mbox.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath6kl/htc_mbox.c b/drivers/net/wireless/ath/ath6kl/htc_mbox.c
index 65c31da43c47..998947ef63b6 100644
--- a/drivers/net/wireless/ath/ath6kl/htc_mbox.c
+++ b/drivers/net/wireless/ath/ath6kl/htc_mbox.c
@@ -2855,8 +2855,8 @@ static void *ath6kl_htc_mbox_create(struct ath6kl *ar)
 	target->dev = kzalloc(sizeof(*target->dev), GFP_KERNEL);
 	if (!target->dev) {
 		ath6kl_err("unable to allocate memory\n");
-		status = -ENOMEM;
-		goto err_htc_cleanup;
+		kfree(target);
+		return NULL;
 	}
 
 	spin_lock_init(&target->htc_lock);
-- 
2.17.0