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From:   Jia-Ju Bai <baijiaju1990@gmail.com>
To:     kvalo@codeaurora.org, davem@davemloft.net,
        colin.king@canonical.com, yuehaibing@huawei.com
Cc:     linux-wireless@vger.kernel.org, b43-dev@lists.infradead.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [PATCH] net: wireless: b43: Avoid possible double calls to b43_one_core_detach()
Date:   Sat,  4 May 2019 17:10:00 +0800
Message-Id: <20190504091000.18665-1-baijiaju1990@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

In b43_request_firmware(), when ieee80211_register_hw() fails,
b43_one_core_detach() is called. In b43_bcma_remove() and
b43_ssb_remove(), b43_one_core_detach() is called again. In this case, 
null-pointer dereferences and double-free problems can occur when 
the driver is removed.

To fix this bug, the call to b43_one_core_detach() in
b43_request_firmware() is deleted.

This bug is found by a runtime fuzzing tool named FIZZER written by us.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
 drivers/net/wireless/broadcom/b43/main.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/net/wireless/broadcom/b43/main.c b/drivers/net/wireless/broadcom/b43/main.c
index 74be3c809225..e666a472a0da 100644
--- a/drivers/net/wireless/broadcom/b43/main.c
+++ b/drivers/net/wireless/broadcom/b43/main.c
@@ -2610,18 +2610,13 @@ static void b43_request_firmware(struct work_struct *work)
 
 	err = ieee80211_register_hw(wl->hw);
 	if (err)
-		goto err_one_core_detach;
+		goto out;
 	wl->hw_registered = true;
 	b43_leds_register(wl->current_dev);
 
 	/* Register HW RNG driver */
 	b43_rng_init(wl);
 
-	goto out;
-
-err_one_core_detach:
-	b43_one_core_detach(dev->dev);
-
 out:
 	kfree(ctx);
 }
-- 
2.17.0