linux-kernel - [PATCH] media: staging: atomisp: rework reading the id and revision values

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 for Android: free password hash cracker in your pocket

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

Message-Id: <20220326191853.2914552-1-trix@redhat.com>
Date:   Sat, 26 Mar 2022 12:18:53 -0700
From:   trix@...hat.com
To:     mchehab@...nel.org, sakari.ailus@...ux.intel.com,
        gregkh@...uxfoundation.org, nathan@...nel.org,
        ndesaulniers@...gle.com, hverkuil-cisco@...all.nl, vrzh@...h.net,
        tomi.valkeinen@...asonboard.com
Cc:     linux-media@...r.kernel.org, linux-staging@...ts.linux.dev,
        linux-kernel@...r.kernel.org, llvm@...ts.linux.dev,
        Tom Rix <trix@...hat.com>
Subject: [PATCH] media: staging: atomisp: rework reading the id and revision values

From: Tom Rix <trix@...hat.com>

Clang static analysis reports this representative issue
atomisp-ov2722.c:920:3: warning: 3rd function call
  argument is an uninitialized value
  dev_err(&client->dev, "sensor_id_high = 0x%x\n", high);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

high and low are only set when ov2722_read_reg() is successful.
Reporting the high value when there is an error is not
meaningful.  The later read for low is not checked.  high
and low are or-ed together and checked against a non zero
value.

Remove the unneeded error reporting for high.  Initialize
high and low to 0 and use the id check to determine if
the reads were successful

The later read for revision is not checked.  If it
fails the old high value will be used and the revision
will be misreported.

Since the revision is only reported and not checked or
stored it is not necessary to return if the read with
successful.  This makes the ret variable unnecessary
so remove it.

Signed-off-by: Tom Rix <trix@...hat.com>
---
 .../media/atomisp/i2c/atomisp-ov2722.c        | 20 ++++++++-----------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/staging/media/atomisp/i2c/atomisp-ov2722.c b/drivers/staging/media/atomisp/i2c/atomisp-ov2722.c
index da98094d7094a..d5d099ac1b707 100644
--- a/drivers/staging/media/atomisp/i2c/atomisp-ov2722.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-ov2722.c
@@ -906,22 +906,17 @@ static int ov2722_get_fmt(struct v4l2_subdev *sd,
 static int ov2722_detect(struct i2c_client *client)
 {
 	struct i2c_adapter *adapter = client->adapter;
-	u16 high, low;
-	int ret;
+	u16 high = 0, low = 0;
 	u16 id;
 	u8 revision;
 
 	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
 		return -ENODEV;
 
-	ret = ov2722_read_reg(client, OV2722_8BIT,
-			      OV2722_SC_CMMN_CHIP_ID_H, &high);
-	if (ret) {
-		dev_err(&client->dev, "sensor_id_high = 0x%x\n", high);
-		return -ENODEV;
-	}
-	ret = ov2722_read_reg(client, OV2722_8BIT,
-			      OV2722_SC_CMMN_CHIP_ID_L, &low);
+	ov2722_read_reg(client, OV2722_8BIT,
+			OV2722_SC_CMMN_CHIP_ID_H, &high);
+	ov2722_read_reg(client, OV2722_8BIT,
+			OV2722_SC_CMMN_CHIP_ID_L, &low);
 	id = (high << 8) | low;
 
 	if ((id != OV2722_ID) && (id != OV2720_ID)) {
@@ -929,8 +924,9 @@ static int ov2722_detect(struct i2c_client *client)
 		return -ENODEV;
 	}
 
-	ret = ov2722_read_reg(client, OV2722_8BIT,
-			      OV2722_SC_CMMN_SUB_ID, &high);
+	high = 0;
+	ov2722_read_reg(client, OV2722_8BIT,
+			OV2722_SC_CMMN_SUB_ID, &high);
 	revision = (u8)high & 0x0f;
 
 	dev_dbg(&client->dev, "sensor_revision = 0x%x\n", revision);
-- 
2.26.3