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Sun, 20 Sep 2026 02:15:42 -0700 (PDT) Received: from fedora ([154.182.123.247]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-49fcd0ece6esm185953065e9.2.2026.09.20.02.15.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 20 Sep 2026 02:15:41 -0700 (PDT) From: Abdelnasser Hussein To: jic23@kernel.org, gregkh@linuxfoundation.org, nuno.sa@analog.com, Michael.Hennerich@analog.com Cc: dlechner@baylibre.com, andy@kernel.org, linux@analog.com, linux-iio@vger.kernel.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, joshua.crofts1@gmail.com, error27@gmail.com, Abdelnasser Hussein Subject: [PATCH v2] staging: iio: adc: ad7816: Protect sysfs attributes with mutex Date: Sun, 20 Sep 2026 12:15:22 +0300 Message-ID: <20260920091522.15507-1-abdelnasserhussein11@gmail.com> X-Mailer: git-send-email 2.54.0 Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The sysfs store functions (ad7816_store_mode and ad7816_store_channel) modify the device state and toggle GPIO pins. If accessed concurrently by userspace during an ongoing SPI transfer, this could corrupt the SPI transaction. Add the existing chip->lock guard to these functions to serialize access and prevent race conditions. Fixes: 7924425db04a ("staging: iio: adc: new driver for AD7816 devices") Suggested-by: Joshua Crofts Reviewed-by: Joshua Crofts Signed-off-by: Abdelnasser Hussein --- Changes in v2: - Added a blank line after guard(mutex) statements as requested by Joshua. - Added Fixes tag as requested by Dan. - Collected Reviewed-by tag from Joshua. drivers/staging/iio/adc/ad7816.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/staging/iio/adc/ad7816.c b/drivers/staging/iio/adc/ad7816.c index f76f0215119a..2a15d7598abb 100644 --- a/drivers/staging/iio/adc/ad7816.c +++ b/drivers/staging/iio/adc/ad7816.c @@ -143,6 +143,8 @@ static ssize_t ad7816_store_mode(struct device *dev, struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct ad7816_chip_info *chip = iio_priv(indio_dev); + guard(mutex)(&chip->lock); + if (strcmp(buf, "full") == 0) { gpiod_set_value(chip->rdwr_pin, 1); chip->mode = AD7816_FULL; @@ -207,6 +209,8 @@ static ssize_t ad7816_store_channel(struct device *dev, return -EINVAL; } + guard(mutex)(&chip->lock); + chip->channel_id = data; return len; -- 2.54.0