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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Claire Chang <tientzu@chromium.org>,
        Brian Norris <briannorris@chromium.org>,
        Kalle Valo <kvalo@codeaurora.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 110/271] ath10k: add missing error handling
Date:   Wed, 24 Jul 2019 21:19:39 +0200
Message-Id: <20190724191704.631736716@linuxfoundation.org>
In-Reply-To: <20190724191655.268628197@linuxfoundation.org>
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[ Upstream commit 4b553f3ca4cbde67399aa3a756c37eb92145b8a1 ]

In function ath10k_sdio_mbox_rx_alloc() [sdio.c],
ath10k_sdio_mbox_alloc_rx_pkt() is called without handling the error cases.
This will make the driver think the allocation for skb is successful and
try to access the skb. If we enable failslab, system will easily crash with
NULL pointer dereferencing.

Call trace of CONFIG_FAILSLAB:
ath10k_sdio_irq_handler+0x570/0xa88 [ath10k_sdio]
process_sdio_pending_irqs+0x4c/0x174
sdio_run_irqs+0x3c/0x64
sdio_irq_work+0x1c/0x28

Fixes: d96db25d2025 ("ath10k: add initial SDIO support")
Signed-off-by: Claire Chang <tientzu@chromium.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/ath/ath10k/sdio.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/ath/ath10k/sdio.c b/drivers/net/wireless/ath/ath10k/sdio.c
index 7f61591ce0de..cb527a21f1ac 100644
--- a/drivers/net/wireless/ath/ath10k/sdio.c
+++ b/drivers/net/wireless/ath/ath10k/sdio.c
@@ -613,6 +613,10 @@ static int ath10k_sdio_mbox_rx_alloc(struct ath10k *ar,
 						    full_len,
 						    last_in_bundle,
 						    last_in_bundle);
+		if (ret) {
+			ath10k_warn(ar, "alloc_rx_pkt error %d\n", ret);
+			goto err;
+		}
 	}
 
 	ar_sdio->n_rx_pkts = i;
-- 
2.20.1