From patchwork Fri Oct 18 05:53:11 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauro Carvalho Chehab X-Patchwork-Id: 13841151 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 7AC76187861; Fri, 18 Oct 2024 05:53:27 +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=1729230807; cv=none; b=KwxE0NV4MLmxeDDhIsexsrzSPqOkD8qFTRheJ6ze9VVpZMwFEzBbInYQwJVuiNgOcntD03eOmv+pFZnJg0lwPZVpnHaTkrMsipFiLrGmKWm5Y40UxlbseqUxDbHogHdxcoZFiS3tueOHcI21r8EqWv2e/bVCivICh0buVDez08c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729230807; c=relaxed/simple; bh=dURN9dIELtyC2m0Zlh5rzANJ1Ev1GACofUTUaXFiXig=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kLePTdgYFRdY6R/V3NnOdem7qgkgY8yAvD6ABIRITVYQdCwvR/fGpwuglXkS5kOO7yY9Ql9Zi3T8XE5AEhgrUU/G590Rx4oS+Bi3a1/Z1A6MU+bttEpoffen2v2woGtT70IVVuMdIwq+vvs+Kb0jgDzwe323HjR+3tzhL5pHriQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FYWWJJ6m; 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="FYWWJJ6m" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C22CAC4CED6; Fri, 18 Oct 2024 05:53:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729230806; bh=dURN9dIELtyC2m0Zlh5rzANJ1Ev1GACofUTUaXFiXig=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FYWWJJ6mf9ei+25Y/KLX5XAHvQZZrcfbkmbsbO5vWYyaJEWjWAUE3NiYmqzjgu2y+ N9SMt+ij9o6yFeEfumEkPcg9OoBzffxNRS+J7IS/c2YCZW4CQElb9eGQZkV20u1+uu wrOPmafBLg9Z6ayfJ1ze95ndteQhUPYFVHQL65t+XaUoN4pBE5raJpDksC1cNeFSfH mNzWFoJ9I3XNgS0x8ZbT2tNxmPJrrL6UrlKhd4Xrg37d7fmVr7Cz3vmikNnLpjDuwD o04QQpjxr1jAzWE4FDEsoHTBcpCZ+NhbMY9sBDlkQpOLK6NrxHV56GUUGcFmzc6+fY tk3ixUG26PRkg== Received: from mchehab by mail.kernel.org with local (Exim 4.98) (envelope-from ) id 1t1fvQ-00000005MeT-27wx; Fri, 18 Oct 2024 07:53:24 +0200 From: Mauro Carvalho Chehab To: Cc: Mauro Carvalho Chehab , Mauro Carvalho Chehab , Steven Toth , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH v2 09/13] media: cx24116: prevent overflows on SNR calculus Date: Fri, 18 Oct 2024 07:53:11 +0200 Message-ID: X-Mailer: git-send-email 2.47.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Sender: Mauro Carvalho Chehab as reported by Coverity, if reading SNR registers fail, a negative number will be returned, causing an underflow when reading SNR registers. Prevent that. Fixes: 8953db793d5b ("V4L/DVB (9178): cx24116: Add module parameter to return SNR as ESNO.") Cc: stable@vger.kernel.org Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb-frontends/cx24116.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/media/dvb-frontends/cx24116.c b/drivers/media/dvb-frontends/cx24116.c index 8b978a9f74a4..f5dd3a81725a 100644 --- a/drivers/media/dvb-frontends/cx24116.c +++ b/drivers/media/dvb-frontends/cx24116.c @@ -741,6 +741,7 @@ static int cx24116_read_snr_pct(struct dvb_frontend *fe, u16 *snr) { struct cx24116_state *state = fe->demodulator_priv; u8 snr_reading; + int ret; static const u32 snr_tab[] = { /* 10 x Table (rounded up) */ 0x00000, 0x0199A, 0x03333, 0x04ccD, 0x06667, 0x08000, 0x0999A, 0x0b333, 0x0cccD, 0x0e667, @@ -749,7 +750,11 @@ static int cx24116_read_snr_pct(struct dvb_frontend *fe, u16 *snr) dprintk("%s()\n", __func__); - snr_reading = cx24116_readreg(state, CX24116_REG_QUALITY0); + ret = cx24116_readreg(state, CX24116_REG_QUALITY0); + if (ret < 0) + return ret; + + snr_reading = ret; if (snr_reading >= 0xa0 /* 100% */) *snr = 0xffff;