Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754095AbaKYLZz (ORCPT ); Tue, 25 Nov 2014 06:25:55 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:58649 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753414AbaKYKmH (ORCPT ); Tue, 25 Nov 2014 05:42:07 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Antti Palosaari , Mauro Carvalho Chehab , Luis Henriques Subject: [PATCH 3.16.y-ckt 126/254] [media] m88ts2022: fix 32bit overflow on filter calc Date: Tue, 25 Nov 2014 10:37:56 +0000 Message-Id: <1416912004-5928-127-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1416912004-5928-1-git-send-email-luis.henriques@canonical.com> References: <1416912004-5928-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt2 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Antti Palosaari commit f538e085138e519e25ae0828bd6c6e7492ce8ca4 upstream. Maximum satellite symbol rate used is 45000000Sps which overflows when multiplied by 135. As final calculation result is fraction, we could use mult_frac macro in order to keep calculation inside 32 bit number limits and prevent overflow. Original bug and fix was provided by Nibble Max. I decided to implement it differently as it is now. Reported-by: Nibble Max Tested-by: Nibble Max Signed-off-by: Antti Palosaari Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Luis Henriques --- drivers/media/tuners/m88ts2022.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/tuners/m88ts2022.c b/drivers/media/tuners/m88ts2022.c index 40c42dec721b..7a62097aa9ea 100644 --- a/drivers/media/tuners/m88ts2022.c +++ b/drivers/media/tuners/m88ts2022.c @@ -314,7 +314,7 @@ static int m88ts2022_set_params(struct dvb_frontend *fe) div_min = gdiv28 * 78 / 100; div_max = clamp_val(div_max, 0U, 63U); - f_3db_hz = c->symbol_rate * 135UL / 200UL; + f_3db_hz = mult_frac(c->symbol_rate, 135, 200); f_3db_hz += 2000000U + (frequency_offset_khz * 1000U); f_3db_hz = clamp(f_3db_hz, 7000000U, 40000000U); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/