linux-kernel - [PATCH v2] iio: adc: adi-axi-adc: fix ad7606_bus_reg

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250530-iio-adc-adi-axi-adc-fix-ad7606_bus_reg_read-v2-1-ad2dfc0694ce@baylibre.com>
Date: Fri, 30 May 2025 16:50:14 -0500
From: David Lechner <dlechner@...libre.com>
To: Michael Hennerich <Michael.Hennerich@...log.com>, 
 Jonathan Cameron <jic23@...nel.org>, 
 Angelo Dureghello <adureghello@...libre.com>, 
 Guillaume Stols <gstols@...libre.com>
Cc: linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org, 
 stable@...r.kernel.org, David Lechner <dlechner@...libre.com>
Subject: [PATCH v2] iio: adc: adi-axi-adc: fix ad7606_bus_reg_read()

Mask the value read before returning it. The value read over the
parallel bus via the AXI ADC IP block contains both the address and
the data, but callers expect val to only contain the data.

axi_adc_raw_write() takes a u32 parameter, so addr was the wrong type.
This wasn't causing any issues but is corrected anyway since we are
touching the same line to add a new variable.

Cc: stable@...r.kernel.org
Fixes: 79c47485e438 ("iio: adc: adi-axi-adc: add support for AD7606 register writing")
Signed-off-by: David Lechner <dlechner@...libre.com>
---
Changes in v2:
- Use ADI_AXI_REG_VALUE_MASK instead of hard-coding 0xFF.
- Introduce local variable and use FIELD_PREP() instead of modifying val.
- Link to v1: https://lore.kernel.org/r/20250530-iio-adc-adi-axi-adc-fix-ad7606_bus_reg_read-v1-1-ce8f7cb4d663@baylibre.com
---
 drivers/iio/adc/adi-axi-adc.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index cf942c043457ccea49207c3900153ee371b3774f..fc745297bcb82cf2cf7f30c7fcf9bba2d861a48c 100644
--- a/drivers/iio/adc/adi-axi-adc.c
+++ b/drivers/iio/adc/adi-axi-adc.c
@@ -445,7 +445,7 @@ static int axi_adc_raw_read(struct iio_backend *back, u32 *val)
 static int ad7606_bus_reg_read(struct iio_backend *back, u32 reg, u32 *val)
 {
 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
-	int addr;
+	u32 addr, reg_val;
 
 	guard(mutex)(&st->lock);
 
@@ -455,7 +455,9 @@ static int ad7606_bus_reg_read(struct iio_backend *back, u32 reg, u32 *val)
 	 */
 	addr = FIELD_PREP(ADI_AXI_REG_ADDRESS_MASK, reg) | ADI_AXI_REG_READ_BIT;
 	axi_adc_raw_write(back, addr);
-	axi_adc_raw_read(back, val);
+	axi_adc_raw_read(back, &reg_val);
+
+	*val = FIELD_GET(ADI_AXI_REG_VALUE_MASK, reg_val);
 
 	/* Write 0x0 on the bus to get back to ADC mode */
 	axi_adc_raw_write(back, 0);

---
base-commit: 7cdfbc0113d087348b8e65dd79276d0f57b89a10
change-id: 20250530-iio-adc-adi-axi-adc-fix-ad7606_bus_reg_read-f2bbb503db8b

Best regards,
-- 
David Lechner <dlechner@...libre.com>