From patchwork Tue Jul 26 06:53:40 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthias Schwarzott X-Patchwork-Id: 35780 Received: from mail.tu-berlin.de ([130.149.7.33]) by www.linuxtv.org with esmtp (Exim 4.84_2) (envelope-from ) id 1bRwFn-0005UG-G1; Tue, 26 Jul 2016 06:54:11 +0000 X-tubIT-Incoming-IP: 209.132.180.67 Received: from vger.kernel.org ([209.132.180.67]) by mail.tu-berlin.de (exim-4.84_2/mailfrontend-7) with esmtp id 1bRwFl-000593-2w; Tue, 26 Jul 2016 08:54:11 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752821AbcGZGyG (ORCPT + 1 other); Tue, 26 Jul 2016 02:54:06 -0400 Received: from smtp.gentoo.org ([140.211.166.183]:54196 "EHLO smtp.gentoo.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751692AbcGZGyF (ORCPT ); Tue, 26 Jul 2016 02:54:05 -0400 Received: from gauss.fritz.box (unknown [IPv6:2001:a62:22e:fe01:292b:df9b:2cc9:507d]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: zzam) by smtp.gentoo.org (Postfix) with ESMTPSA id 051F4340B46; Tue, 26 Jul 2016 06:54:02 +0000 (UTC) From: Matthias Schwarzott To: linux-media@vger.kernel.org Cc: mchehab@osg.samsung.com, crope@iki.fi, Matthias Schwarzott Subject: [PATCH] si2165: avoid division by zero Date: Tue, 26 Jul 2016 08:53:40 +0200 Message-Id: <20160726065340.7396-1-zzam@gentoo.org> X-Mailer: git-send-email 2.9.2 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-PMX-Version: 6.0.0.2142326, Antispam-Engine: 2.7.2.2107409, Antispam-Data: 2016.7.26.64216 X-PMX-Spam: Gauge=IIIIIIII, Probability=8%, Report=' MULTIPLE_RCPTS 0.1, HTML_00_01 0.05, HTML_00_10 0.05, BODYTEXTP_SIZE_3000_LESS 0, BODY_SIZE_1500_1599 0, BODY_SIZE_2000_LESS 0, BODY_SIZE_5000_LESS 0, BODY_SIZE_7000_LESS 0, ECARD_WORD 0, LEGITIMATE_NEGATE 0, MULTIPLE_RCPTS_RND 0, NO_URI_HTTPS 0, SINGLE_URI_IN_BODY 0, URI_ENDS_IN_HTML 0, __ANY_URI 0, __CP_URI_IN_BODY 0, __HAS_CC_HDR 0, __HAS_FROM 0, __HAS_MSGID 0, __HAS_X_MAILER 0, __HAS_X_MAILING_LIST 0, __MIME_TEXT_ONLY 0, __MULTIPLE_RCPTS_CC_X2 0, __SANE_MSGID 0, __SINGLE_URI_TEXT 0, __SUBJ_ALPHA_END 0, __TO_MALFORMED_2 0, __TO_NO_NAME 0, __URI_IN_BODY 0, __URI_NO_WWW 0, __URI_NS , __URI_WITH_PATH 0' When si2165_init fails, the clk values in state are still at zero. But the dvb-core ignores the return value of init will call tune afterwards. This will trigger a division by zero when tuning. At least check for the variables to be non-zero before dividing. This happened for a system with WinTV HVR-4400 PCIe-card after suspend-to-disk. Do suspend-to-disk without accessing the DVB device before. After wakeup try to tune. si2165_init fails at checking the chip_mode and aborts. Then si2165_set_if_freq_shift will fail with div-by-zero. Signed-off-by: Matthias Schwarzott --- drivers/media/dvb-frontends/si2165.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/media/dvb-frontends/si2165.c b/drivers/media/dvb-frontends/si2165.c index 8bf716a..849c3c4 100644 --- a/drivers/media/dvb-frontends/si2165.c +++ b/drivers/media/dvb-frontends/si2165.c @@ -751,6 +751,9 @@ static int si2165_set_oversamp(struct si2165_state *state, u32 dvb_rate) u64 oversamp; u32 reg_value; + if (!dvb_rate) + return -EINVAL; + oversamp = si2165_get_fe_clk(state); oversamp <<= 23; do_div(oversamp, dvb_rate); @@ -775,6 +778,9 @@ static int si2165_set_if_freq_shift(struct si2165_state *state) return -EINVAL; } + if (!fe_clk) + return -EINVAL; + fe->ops.tuner_ops.get_if_frequency(fe, &IF); if_freq_shift = IF; if_freq_shift <<= 29;