From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-516909-1519835056-2-5487168364027846731 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.249, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES unknown, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='uk', MailFrom='org' X-Spam-charsets: cc='UTF-8', plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1519835055; b=UsTGGzzbfUYgiF4IqpIk66jxl1WUzWrNBjv3gMbqj6w+sgF 6NqJJPjsOtI4NxEIuhGMGJTiYC3rJluGoZCwMNk6jZcbI9AnYBgvXLmQOEBFqTDm Va32dmQJxbphlmaKDiaBkQ65Q7tnVT0OIjXZNuPFDYIGYoh5CeQTTuLQqtkHGoSz Z9ApvYGOZA7AiCz2Ys9u3Ry2VuAd/5myNULLEGN0eKuOLRBpzG+4qlBODOC3qDof RiB29cHIloIjm24ga/brtNYWC4OjUKqS1e9DKwlMy40BK7aVCY0owquKEWQkR9gW 3W6rApNugY1FM+S73Qt2uH/rfVYJdEeEe1kVkUg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-type:content-transfer-encoding :mime-version:from:to:cc:date:message-id:subject:in-reply-to :sender:list-id; s=arctest; t=1519835055; bh=MAi84YeOo6JMZwJKilO Q23xZu0J9R7FNuIygZ5j6is0=; b=e+Mdc8QcUeQQTeP2ZJxfKXG0W+RnGyzs7gX g/KFnJKDix3iLg2AzirxFoCvAApS04aGJb1/ZLuoZZJK70liIUdy+axWW5cNCRNW LkBq3z2WiL+1lXpPWWgfmSa+7ToZY5FRInAy68cbXan/RNw9SBasepI/6qWwx3iL /L1O4tqtbnayloYUTorKl4x+zS/LgQOZEkmMoMGuB4r9jW0csb1XfGWWnoilbd+h cJ5Ic6DoFar1T7cK++1uD+OeAs4/s7Yzey0wwsqeS9uayRsezBzlcXDcoByJKfKm WnyPmkr76XaTRTC2xBRBF4HXgKD9EF0Bkg+zwLKpO6nmIPJHngA== ARC-Authentication-Results: i=1; mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Authentication-Results: mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935190AbeB1QUm (ORCPT ); Wed, 28 Feb 2018 11:20:42 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35375 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935188AbeB1QUk (ORCPT ); Wed, 28 Feb 2018 11:20:40 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Chris Wilson" , "Daniel Vetter" , "Daniel Kurtz" , "Sean Paul" , "=?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?=" , "Joonas Lahtinen" Date: Wed, 28 Feb 2018 15:20:18 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 019/254] drm/i915: Prevent zero length "index" write In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 3.16.55-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Ville Syrjälä commit 56350fb8978bbf4aafe08f21234e161dd128b417 upstream. The hardware always writes one or two bytes in the index portion of an indexed transfer. Make sure the message we send as the index doesn't have a zero length. Cc: Daniel Kurtz Cc: Chris Wilson Cc: Daniel Vetter Cc: Sean Paul Fixes: 56f9eac05489 ("drm/i915/intel_i2c: use INDEX cycles for i2c read transactions") Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20171123194157.25367-3-ville.syrjala@linux.intel.com Reviewed-by: Chris Wilson (cherry picked from commit bb9e0d4bca50f429152e74a459160b41f3d60fb2) Signed-off-by: Joonas Lahtinen Signed-off-by: Ben Hutchings --- drivers/gpu/drm/i915/intel_i2c.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -449,7 +449,8 @@ gmbus_is_index_read(struct i2c_msg *msgs { return (i + 1 < num && msgs[i].addr == msgs[i + 1].addr && - !(msgs[i].flags & I2C_M_RD) && msgs[i].len <= 2 && + !(msgs[i].flags & I2C_M_RD) && + (msgs[i].len == 1 || msgs[i].len == 2) && (msgs[i + 1].flags & I2C_M_RD)); }