From nobody Sat Apr 11 03:52:12 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6937CC25B0E for ; Tue, 16 Aug 2022 12:39:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232208AbiHPMjN (ORCPT ); Tue, 16 Aug 2022 08:39:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234664AbiHPMjD (ORCPT ); Tue, 16 Aug 2022 08:39:03 -0400 Received: from mx.swemel.ru (mx.swemel.ru [95.143.211.150]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60AE698D02 for ; Tue, 16 Aug 2022 05:39:00 -0700 (PDT) From: Denis Arefev DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=swemel.ru; s=mail; t=1660653538; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=JLCOqrmDxlScPWlMM0m9RZxSSqsKrmtABPqJmneo9vE=; b=lPvfMm6cXnmUBjJ+mYGDCPWs8YhvsFE1jDJeZQszcdhtyBjJkdfWhb2x/VmHT0nQ4nF9Kl g7/0lqEmD2bJmvP5gcTXIp8L2cnjw2c4HYs3MQbo4hgMDv1dRmnOHjilgsZJ0zI4F9XxKO lAzoq3CSGXd7EA6mS2cU+kimz1gfdXk= To: Jani Nikula Cc: Joonas Lahtinen , Rodrigo Vivi , David Airlie , Daniel Vetter , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org Subject: [PATCH] i915-pmu: Add extra check engine Date: Tue, 16 Aug 2022 15:38:57 +0300 Message-Id: <20220816123858.42489-1-arefev@swemel.ru> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Return value of a function 'intel_engine_lookup_user' is dereferenced at i9= 15_pmu.c:708 without checking for null, but it is usually checked for this function Found by Linux Verification Center (linuxtesting.org) with SVACE. Signed-off-by: Denis Arefev --- drivers/gpu/drm/i915/i915_pmu.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pm= u.c index 69c0fa20eba1..33db49ffac3d 100644 --- a/drivers/gpu/drm/i915/i915_pmu.c +++ b/drivers/gpu/drm/i915/i915_pmu.c @@ -704,8 +704,10 @@ static void i915_pmu_disable(struct perf_event *event) * Decrement the reference count and clear the enabled * bitmask when the last listener on an event goes away. */ - if (--engine->pmu.enable_count[sample] =3D=3D 0) - engine->pmu.enable &=3D ~BIT(sample); + if (engine !=3D NULL) { + if (--engine->pmu.enable_count[sample] =3D=3D 0) + engine->pmu.enable &=3D ~BIT(sample); + } } =20 GEM_BUG_ON(bit >=3D ARRAY_SIZE(pmu->enable_count)); --=20 2.25.1