From mboxrd@z Thu Jan 1 00:00:00 1970 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 82808C433F5 for ; Tue, 30 Nov 2021 14:26:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242155AbhK3O3b (ORCPT ); Tue, 30 Nov 2021 09:29:31 -0500 Received: from mta-p7.oit.umn.edu ([134.84.196.207]:58238 "EHLO mta-p7.oit.umn.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236374AbhK3O3a (ORCPT ); Tue, 30 Nov 2021 09:29:30 -0500 Received: from localhost (unknown [127.0.0.1]) by mta-p7.oit.umn.edu (Postfix) with ESMTP id 4J3PfB6JhCz9w98y for ; Tue, 30 Nov 2021 14:26:10 +0000 (UTC) X-Virus-Scanned: amavisd-new at umn.edu Received: from mta-p7.oit.umn.edu ([127.0.0.1]) by localhost (mta-p7.oit.umn.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id b_E4O6-wRzs5 for ; Tue, 30 Nov 2021 08:26:10 -0600 (CST) Received: from mail-pg1-f197.google.com (mail-pg1-f197.google.com [209.85.215.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mta-p7.oit.umn.edu (Postfix) with ESMTPS id 4J3PfB42T8z9w98v for ; Tue, 30 Nov 2021 08:26:10 -0600 (CST) DMARC-Filter: OpenDMARC Filter v1.3.2 mta-p7.oit.umn.edu 4J3PfB42T8z9w98v DKIM-Filter: OpenDKIM Filter v2.11.0 mta-p7.oit.umn.edu 4J3PfB42T8z9w98v Received: by mail-pg1-f197.google.com with SMTP id d2-20020a656202000000b00325603f7d0bso4891091pgv.12 for ; Tue, 30 Nov 2021 06:26:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=umn.edu; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=KuQ42+umRcpPW+VMKGxj6sWr71Sv5xh4Rg14DLaks5k=; b=PwoWlRWAMO0iWwLAo/aYQlakXElaCjD6VMo9NBp2f3HZSFUvXsfa1haSpu3NFk/jqH NljBRNM+7/3cQ89MDBH/6XqBC09gzgT/mLtnMdxH4K2ayiigmRu/zgfryY9PbWqCxlxj wsP1JQQ8Be0QOJ32s2uUM+JgauLV4N1tX6MRxaqvbBZVWzPKOM0xaISKrzkQDV0puX7Y RXFJxbQQBqpoasb/eaceP+V2HBd5Tp+1BQFaM9eCgscf1Lq99qVeFpjPP0ZYfONxNT6M pF/QV7sJRxs3Dv0ewAtua/bhkFQHWIrYdh1svhjso2tqPwrsMiUQEHCxdST3i8RflN7K ssFg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=KuQ42+umRcpPW+VMKGxj6sWr71Sv5xh4Rg14DLaks5k=; b=sU7CdSJ81S0QhdHrWGQHgeXsUCoeKxprAbFibfoxf/HqNobaHNr4i7xcFOfsH348+T dICCPxjCMMzAO72b2yo8oOd6bXgE3uBVs3Ov9O9GvIopEGLCTwqyF8zQ0BXyfwaqc7XV pUx3NZaT2imMe05Ey69IVlOoibecCW8wFkfAC2a0aCftRUdCiHIY+y7z3FCl9B22ecJz WlhFahN8WtQgQsaQOwIBZHVt7KJNqezAwG653DqxFNv6/UVvA3cN1XDJoXkT4DW+AkI4 bzwYar1rjkPvI5UtBQJNxo4FE7nvXIzJejK4GU4QIzk00Kt7b3l2WggQ19ZdwAFaohtt QQ0A== X-Gm-Message-State: AOAM532nfS2ShLzXwrM5hZngMBSpOo5E9ndRTHaMaTzGtJ96QsoHnXH6 8e9AgHZlEwlGFc4PPSbmqXMOkycMfO9o5VQgmTMfuWtdD7aG85+rvMCngbZa0ZhH2NxHm5COQKy jjR73vC5YMz03C8sOGkJPrOHYTgjz X-Received: by 2002:a17:90a:2fc7:: with SMTP id n7mr6378167pjm.141.1638282369883; Tue, 30 Nov 2021 06:26:09 -0800 (PST) X-Google-Smtp-Source: ABdhPJx7GdydZXDEWnsAUZ7LT9R88o7lt/wXSRMThDt6spxy2SRR9dULTljXwp0Ihnwi8tcyqu8CCQ== X-Received: by 2002:a17:90a:2fc7:: with SMTP id n7mr6378125pjm.141.1638282369630; Tue, 30 Nov 2021 06:26:09 -0800 (PST) Received: from zqy787-GE5S.lan ([36.7.42.137]) by smtp.gmail.com with ESMTPSA id k19sm21540692pff.20.2021.11.30.06.26.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Nov 2021 06:26:09 -0800 (PST) From: Zhou Qingyang To: zhou1615@umn.edu Cc: kjlu@umn.edu, "James (Qian) Wang" , Liviu Dudau , Mihail Atanassov , Brian Starkey , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH] drm/komeda: Fix an undefined behavior bug in komeda_plane_add() Date: Tue, 30 Nov 2021 22:25:31 +0800 Message-Id: <20211130142531.156863-1-zhou1615@umn.edu> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In komeda_plane_add(), komeda_get_layer_fourcc_list() is assigned to formats and used in drm_universal_plane_init(). drm_universal_plane_init() passes formats to __drm_universal_plane_init(). __drm_universal_plane_init() further passes formats to memcpy() as src parameter, which could lead to an undefined behavior bug on failure of komeda_get_layer_fourcc_list(). Fix this bug by adding a check of formats. This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs. Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. Builds with CONFIG_DRM_KOMEDA=m show no new warnings, and our static analyzer no longer warns about this code. Fixes: 61f1c4a8ab75 ("drm/komeda: Attach komeda_dev to DRM-KMS") Signed-off-by: Zhou Qingyang --- drivers/gpu/drm/arm/display/komeda/komeda_plane.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_plane.c b/drivers/gpu/drm/arm/display/komeda/komeda_plane.c index d63d83800a8a..dd3f17e970dd 100644 --- a/drivers/gpu/drm/arm/display/komeda/komeda_plane.c +++ b/drivers/gpu/drm/arm/display/komeda/komeda_plane.c @@ -265,6 +265,10 @@ static int komeda_plane_add(struct komeda_kms_dev *kms, formats = komeda_get_layer_fourcc_list(&mdev->fmt_tbl, layer->layer_type, &n_formats); + if (!formats) { + err = -ENOMEM; + goto cleanup; + } err = drm_universal_plane_init(&kms->base, plane, get_possible_crtcs(kms, c->pipeline), -- 2.25.1