From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 4E1E853D9D1; Thu, 15 Oct 2026 15:19:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792077571; cv=none; b=PC0WtAU9kbMXrpfz3ppEDTI30JmNFAhcFX/93S9m7yHlPdgLIt64nT9KoN8WIaaa3S7vqXOqVDPa9mko5j1UgumK68MqOSdL2sHIdRFR+NO+C8ouBaYJ5W8LjvyV8X+IVzOH3rlr5ykCiVQ1aj9u+ZzKyqSW1FfQBApUdu/xz0Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792077571; c=relaxed/simple; bh=EZUeNbmpfJYyDpKgx/wfa8dJ6ZCnpjyl7hPuRdP6xRo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BVscDCbJQLSeximwaNOo9xYc7/xygCXC05M+rQZCgXIjJp7REPbMHcA7nDciXCUg9adU+35SmlYZhcwVIU5/d53KD9p+vPYiEqY049dCpCxiLVSVFSD0Iqhz8QOis2m01/Y5NAFPYl9nIAU0fkfiDRaIFmG59n+QXgQSKH567mo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=e/UvBqAk; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="e/UvBqAk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA3571F000C4; Thu, 15 Oct 2026 15:19:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792077569; bh=Q4YhG24UUHdygj6VRaqvhrJ15ACDfiSdDeOEIq1CZ1I=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=e/UvBqAkIn0RbxKqFHJHJksge81HcPiAbt8t0cIwEm3fa98ItFw/aYt3gWwVW4p06 RycX9Yr41lSpvRyFxFU1LDMwMhsetTP8CXsBuvK0+WYEnBXF2MmZaarETqnrvmjCyk 8kmVk62pePQ9rVExMVbuFBHAmJJKTO//BRiGFCBfx0vx2MPP5ZbiZPYLf/e9UwdHFg hyS/27fJgvlh+D3olBLgb7f4SH7RA4YwdM5pVn7tFJrwiOfyQKl7YGciO5+sGF7xBe tfM/OTJPgVlmeepUdInjy0cBCMqXgXuZtCaKg7QL9kV3RxRX6GXGgSw1kbnghOm+jL b/kvrANhEwWew== Date: Thu, 15 Oct 2026 16:19:25 +0100 From: Lee Jones To: Thomas Richard Cc: Andi Shyti , Thomas Petazzoni , Werner Gartner , mfd@lists.linux.dev, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, stable@vger.kernel.org, Sashiko Subject: Re: [PATCH v4 1/9] mfd: cgbc: Fix use of negative error code as valid session handle Message-ID: <179198454582.839288.18173091548459871170@kernel.org> References: <20261002-cgbc-i2c-storage-devices-support-v4-0-eb42e0f1df59@bootlin.com> <20261002-cgbc-i2c-storage-devices-support-v4-1-eb42e0f1df59@bootlin.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261002-cgbc-i2c-storage-devices-support-v4-1-eb42e0f1df59@bootlin.com> X-AI-Review-Draft: <20261002-cgbc-i2c-storage-devices-support-v4-1-eb42e0f1df59@bootlin.com> On Fri, 02 Oct 2026, Thomas Richard (congatec GmbH) wrote: > The cgbc_session_command() return value was directly cast to u8 and used > as session handle without error checking. Casting a negative error to u8 > produces a valid-looking session handle. So check if return value is > positive before to cast and use it. > > Cc: stable@vger.kernel.org > Reported-by: Sashiko > Closes: https://sashiko.dev/#/patchset/20260713-cgbc-core-fix-cgbc-remove-v1-1-79274ad62b3a%40bootlin.com?part=1 > Fixes: 6f1067cfbee7 ("mfd: Add Congatec Board Controller driver") > Signed-off-by: Thomas Richard (congatec GmbH) > --- > drivers/mfd/cgbc-core.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/mfd/cgbc-core.c b/drivers/mfd/cgbc-core.c > index 2becaf797646..4a409234e66c 100644 > --- a/drivers/mfd/cgbc-core.c > +++ b/drivers/mfd/cgbc-core.c > @@ -103,7 +103,11 @@ static int cgbc_session_request(struct cgbc_device_data *cgbc) > if (ret) > return dev_err_probe(cgbc->dev, ret, "device not found or not ready\n"); > > - cgbc->session = cgbc_session_command(cgbc, CGBC_SESSION_CMD_REQUEST); > + ret = cgbc_session_command(cgbc, CGBC_SESSION_CMD_REQUEST); > + if (ret < 0) > + return dev_err_probe(cgbc->dev, ret, "session handle request timed out\n"); As previously requested, can we make this a bit more user friendly? "Failed to start XYZ session" > + > + cgbc->session = ret; > > /* The Board Controller sent us a wrong session handle, we cannot communicate with it */ > if (cgbc->session < CGBC_SESSION_VALID_MIN || cgbc->session > CGBC_SESSION_VALID_MAX) > > -- > 2.53.0 > -- Lee Jones