From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1499B190688; Sat, 19 Oct 2024 11:21:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729336901; cv=none; b=bC/cBPhxsebf1UYVLD/dI9eEawlq3uTLhal1Ukg63rUVVDyJmCdSAP/c4KS7unD2HOG8OuWShbtdT4mb8VqI30JLVgBkJR3LzancGIjFGPi4EljIAe7H3TacdOiQJAQp7EjluXLZXlUsKImFXTT8vXKZamkJigcm3dNqRgODjZk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729336901; c=relaxed/simple; bh=SCOetsuGhfRBZ8vqKCa3ek94gu4iy9K9KCUmNwI3Mp0=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ZME7NvGd6p8pzN3dTOK6457Rd7wCzUlJzD1cxAolOamvkow1ZaR69ZpmfY8NnmMlf/jF1dMiYfciPZG3LMZFSvneQJuTMR/wKvz/NbWxtjJvLqJEwQ3mzH5ANCOQtw2KwJVit8Zql1pcw5Wa5GMflX9c8zyLTkVtACzeo0wVX4Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=S6/3tdCD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="S6/3tdCD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13AF5C4CEC5; Sat, 19 Oct 2024 11:21:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729336900; bh=SCOetsuGhfRBZ8vqKCa3ek94gu4iy9K9KCUmNwI3Mp0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=S6/3tdCDllu2W5eRL/wtq0TZnYHw1FbFTL/gbyLzS1DYABjzuArbWE46AWJxUlWJO /w4QP20oHlSXkmCmrbWYf1W71nKAebJsso4zRFMIdPTiFudzPtSQOF+IxlTyoCqCbV 4LrheCa57/Dr+0q2i0IcuZYOpnsVU2DRa5Q+CGfCp9PzI3vPkBlgOKJ49e3lvMrvY8 EmekIKCleMqBrTNpPzP78QVqmxMj0aS+tHjneN26XF3txgnWeyQdQtUsKXLAJhXbEg 6wC1DEqmy6Yh2SWu6hZHifxgdO4hQNbcLr4eo1d/Kazgbt4EnSGqnBG2ZEmV2eIu/Z kf2lNxyE6iusg== Date: Sat, 19 Oct 2024 12:21:33 +0100 From: Jonathan Cameron To: Karan Sanghavi Cc: Tomasz Duszynski , Lars-Peter Clausen , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Shuah Khan , Karan Sanghavi Subject: Re: [PATCH] iio: chemical: sps30: Add Null pointer check Message-ID: <20241019122133.13d59dfb@jic23-huawei> In-Reply-To: <20241018-cid1593398badshift-v1-1-11550a10ff25@gmail.com> References: <20241018-cid1593398badshift-v1-1-11550a10ff25@gmail.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.43; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Fri, 18 Oct 2024 18:54:42 +0000 Karan Sanghavi wrote: > Add a Null pointer check before assigning and incrementing > the null pointer > > Signed-off-by: Karan Sanghavi It would be a bug if rsp_size was anything other than 0 and rsp is NULL. So this looks like a false positive as the loop will never be entered. How did you find it, in particular have you managed to trigger this in the driver? Jonathan > --- > drivers/iio/chemical/sps30_i2c.c | 20 +++++++++++--------- > 1 file changed, 11 insertions(+), 9 deletions(-) > > diff --git a/drivers/iio/chemical/sps30_i2c.c b/drivers/iio/chemical/sps30_i2c.c > index 1b21b6bcd0e7..d2142e4c748c 100644 > --- a/drivers/iio/chemical/sps30_i2c.c > +++ b/drivers/iio/chemical/sps30_i2c.c > @@ -105,16 +105,18 @@ static int sps30_i2c_command(struct sps30_state *state, u16 cmd, void *arg, size > return ret; > > /* validate received data and strip off crc bytes */ > - tmp = rsp; > - for (i = 0; i < rsp_size; i += 3) { > - crc = crc8(sps30_i2c_crc8_table, buf + i, 2, CRC8_INIT_VALUE); > - if (crc != buf[i + 2]) { > - dev_err(state->dev, "data integrity check failed\n"); > - return -EIO; > + if (rsp) { > + tmp = rsp; > + for (i = 0; i < rsp_size; i += 3) { > + crc = crc8(sps30_i2c_crc8_table, buf + i, 2, CRC8_INIT_VALUE); > + if (crc != buf[i + 2]) { > + dev_err(state->dev, "data integrity check failed\n"); > + return -EIO; > + } > + > + *tmp++ = buf[i]; > + *tmp++ = buf[i + 1]; > } > - > - *tmp++ = buf[i]; > - *tmp++ = buf[i + 1]; > } > > return 0; > > --- > base-commit: f2493655d2d3d5c6958ed996b043c821c23ae8d3 > change-id: 20241018-cid1593398badshift-9c512a3b92d9 > > Best regards,