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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Bartosz Golaszewski <bartosz.golaszewski@linaro.org>,
        Mark Brown <broonie@kernel.org>,
        Sasha Levin <sashal@kernel.org>, linux-spi@vger.kernel.org
Subject: [PATCH AUTOSEL 5.15 17/24] spi: spidev: remove debug messages that access spidev->spi without locking
Date:   Mon, 16 Jan 2023 09:03:52 -0500
Message-Id: <20230116140359.115716-17-sashal@kernel.org>
In-Reply-To: <20230116140359.115716-1-sashal@kernel.org>
References: <20230116140359.115716-1-sashal@kernel.org>
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From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

[ Upstream commit 6b35b173dbc1711f8d272e3f322d2ad697015919 ]

The two debug messages in spidev_open() dereference spidev->spi without
taking the lock and without checking if it's not null. This can lead to
a crash. Drop the messages as they're not needed - the user-space will
get informed about ENOMEM with the syscall return value.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20230106100719.196243-2-brgl@bgdev.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/spi/spidev.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index 2cfbf840410a..6e978dad72dc 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -594,7 +594,6 @@ static int spidev_open(struct inode *inode, struct file *filp)
 	if (!spidev->tx_buffer) {
 		spidev->tx_buffer = kmalloc(bufsiz, GFP_KERNEL);
 		if (!spidev->tx_buffer) {
-			dev_dbg(&spidev->spi->dev, "open/ENOMEM\n");
 			status = -ENOMEM;
 			goto err_find_dev;
 		}
@@ -603,7 +602,6 @@ static int spidev_open(struct inode *inode, struct file *filp)
 	if (!spidev->rx_buffer) {
 		spidev->rx_buffer = kmalloc(bufsiz, GFP_KERNEL);
 		if (!spidev->rx_buffer) {
-			dev_dbg(&spidev->spi->dev, "open/ENOMEM\n");
 			status = -ENOMEM;
 			goto err_alloc_rx_buf;
 		}
-- 
2.35.1