From nobody Mon Jun 29 19:37:06 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 2AF8EC433F5 for ; Thu, 3 Feb 2022 15:23:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351798AbiBCPXV (ORCPT ); Thu, 3 Feb 2022 10:23:21 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:26155 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231181AbiBCPXT (ORCPT ); Thu, 3 Feb 2022 10:23:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1643901798; 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=FyaICBNYXFogXQpGuOXvlvkFpwrbiEbZFhG8GrBvphk=; b=F07RxNi0SjZh2ANuhrls5fm7sqOcOObbOCVsHcZ95Q5jH3BBjPgA6FPl/+3s+92Qyfkhqx c9hDRHu6BaJxG9SoFXv7ol9CFvF6iqFAs23yl0RXRuFFiElCsUI3nX6agPAkUz9QuCErLi IoQaq5lEXCMNnthE8WNQMNM7Q+kwbPs= Received: from mail-qt1-f197.google.com (mail-qt1-f197.google.com [209.85.160.197]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-8-gxxQFHh2MraLoSyhY3zw3w-1; Thu, 03 Feb 2022 10:23:17 -0500 X-MC-Unique: gxxQFHh2MraLoSyhY3zw3w-1 Received: by mail-qt1-f197.google.com with SMTP id w25-20020ac84d19000000b002d2966d66a8so2165621qtv.18 for ; Thu, 03 Feb 2022 07:23:17 -0800 (PST) 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=FyaICBNYXFogXQpGuOXvlvkFpwrbiEbZFhG8GrBvphk=; b=zJuBpvf4nc2nSOj27pkR1FQONi4B1V9fn7JTtcMLqEoKJ28mteIpyZdKwjYyinygre KKlxOlSEjjiY0APPqlvMI8bb8qBKaZj8vwU7APf1fkomSkbEElxedyfoe37YE1w934Yj r0RCSeH9E7TY0FgK7dGy+41kRe39VwFFcMfls7ALFcx3ME+fDKB3o5c7hbwNl6rwL72m 33PJfPs6rI4jfqoMowe6iXdcbliaSy2wcSud8dBG4DGuOr7YFzvvG6A8jkefhjyE9F9v Z43LLp+u+nC+uykCkcGdss+nVwkZ8Y25u5LEg5r8gXnehWV7RMlSk5BSqRniWA1vv8bl MTqg== X-Gm-Message-State: AOAM532KkQ6l3UDqRSYJPyijFCubsTTF4cjjfwChu1VRn42IOrYvZ6mL fr/l80CyIiDrULBWquxbyImgrNir50jBgyNpQhpffrTRSb/oUasoMNu7oNz21g/TNfuDGNHfDV5 BL2qFs2QutnpLEfEi2E6f+LXP X-Received: by 2002:a05:6214:767:: with SMTP id f7mr31309315qvz.32.1643901797238; Thu, 03 Feb 2022 07:23:17 -0800 (PST) X-Google-Smtp-Source: ABdhPJzKoZK62v8/DrZws5sOsM70Uxo6BwdmPV1YiNBPk723GMaQhV5IIhjTr/Mj5MVVcyOlC4yv6g== X-Received: by 2002:a05:6214:767:: with SMTP id f7mr31309297qvz.32.1643901797012; Thu, 03 Feb 2022 07:23:17 -0800 (PST) Received: from localhost.localdomain.com (024-205-208-113.res.spectrum.com. [24.205.208.113]) by smtp.gmail.com with ESMTPSA id w22sm9746568qtk.7.2022.02.03.07.23.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Feb 2022 07:23:16 -0800 (PST) From: trix@redhat.com To: airlied@redhat.com, tzimmermann@suse.de, airlied@linux.ie, daniel@ffwll.ch, nathan@kernel.org, ndesaulniers@google.com, maxime@cerno.tech Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, Tom Rix Subject: [PATCH] drm/ast: fix using freed memory Date: Thu, 3 Feb 2022 07:23:05 -0800 Message-Id: <20220203152305.1846862-1-trix@redhat.com> X-Mailer: git-send-email 2.26.3 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" From: Tom Rix clang static analysis reports this problem ast_mode.c:1235:3: warning: Use of memory after it is freed drm_connector_update_edid_property(&ast_connector->base, edid); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The second condition on if (!flags && ast_connector->i2c) Means that the edid is not always set. If the previous block fails the freed edid value will be used. So set edid to NULL after freeing. Fixes: 55dc449a7c60 ("drm/ast: Handle failed I2C initialization gracefully") Signed-off-by: Tom Rix Reviewed-by: Nick Desaulniers --- drivers/gpu/drm/ast/ast_mode.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index ab52efb15670e..9131dc8a1a2fc 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -1224,10 +1224,12 @@ static int ast_get_modes(struct drm_connector *conn= ector) return -ENOMEM; =20 flags =3D ast_dp501_read_edid(connector->dev, (u8 *)edid); - if (flags) + if (flags) { ast->dp501_maxclk =3D ast_get_dp501_max_clk(connector->dev); - else + } else { kfree(edid); + edid =3D NULL; + } } if (!flags && ast_connector->i2c) edid =3D drm_get_edid(connector, &ast_connector->i2c->adapter); --=20 2.26.3