iio: accel: mma9551_core: Prevent uninitialized variable in mma9551_read_status_word()

[ Upstream commit e56d2c34ce9dc122b1a618172ec0e05e50adb9e9 ]

Smatch Warns: drivers/iio/accel/mma9551_core.c:357
	mma9551_read_status_word() error: uninitialized symbol 'v'.

When (offset >= 1 << 12) is true mma9551_transfer() will return -EINVAL
without 'v' being initialized, so check for the error and return.

Note: Not a bug as such because the caller checks return value and
doesn't not use this parameter in the problem case.

Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Link: https://lore.kernel.org/r/20230126152147.3585874-1-harshit.m.mogalapalli@oracle.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/iio/accel/mma9551_core.c b/drivers/iio/accel/mma9551_core.c
index 64ca7d7..86437dd 100644 (file)
--- a/drivers/iio/accel/mma9551_core.c
+++ b/drivers/iio/accel/mma9551_core.c
@@ -354,9 +354,12 @@ int mma9551_read_status_word(struct i2c_client *client, u8 app_id,
 
        ret = mma9551_transfer(client, app_id, MMA9551_CMD_READ_STATUS,
                               reg, NULL, 0, (u8 *)&v, 2);
+       if (ret < 0)
+               return ret;
+
        *val = be16_to_cpu(v);
 
-       return ret;
+       return 0;
 }
 EXPORT_SYMBOL_NS(mma9551_read_status_word, IIO_MMA9551);