From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 E05DB2F21 for ; Thu, 3 Feb 2022 15:23:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1643901803; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=FyaICBNYXFogXQpGuOXvlvkFpwrbiEbZFhG8GrBvphk=; b=IXf23GRhnf1Q0dIMTGx7m3brSMqYpw6Qa4e+LZNmzKnWaldcG/mKN1KfEGxO9dJLYMZVOO Cd4BKIer66Fjr63TkOMCt/lSw3SBHdYxnOuuCs+iDeGEvPRM9nkdUUxfkyifvrF77OikA7 yRG14/QPqV87N/V0QDt6Rs2PWMl1u+8= Received: from mail-qt1-f200.google.com (mail-qt1-f200.google.com [209.85.160.200]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-645-C1R4BmqcPCSRvBDxeIoWvw-1; Thu, 03 Feb 2022 10:23:17 -0500 X-MC-Unique: C1R4BmqcPCSRvBDxeIoWvw-1 Received: by mail-qt1-f200.google.com with SMTP id s1-20020ac85ec1000000b002cf7c93d56dso2165158qtx.21 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=1NfwhnUfhwBGQIqn0L1QnzbwtS7AibvSZLwsUmcXUEKe3a4DpTNe4YfGFuMG/EzGko k9R/dejDheyBgJpynJbbKyvNhE4rYNawcR8KwFIEzGIC79LKBYUnFVxYMp5vkN2Y1Aty tPFQ106UdyUX1Koinl/Eyonog+cDkOLpACql7M4dYOCW2M/Jz0I2ctX7c2T12lJEkt+f st0Pl37KnNIpWLITINHzr9e0BKpFKmNFqN19G9KLOGLwnTX+DFHnduTwU5hqhjKQfrA1 DivKXrtwKf8fU/+ys7vH3gJRfXaaX49C43wyxrPwCsScaaw1IuM7BkA7Y/twysAoN1En bxgQ== X-Gm-Message-State: AOAM5330W2017ulhvTRugNvlfoRtFaWUsuOU5H5N+KEUAlrD+PGslH/H hDHVfFhPUMhY2MR6L2a0+/5lYFU0GP1zLbPZW4lKuy/dbuzjwiEfxO0AgWXkGMFVdXV8JX9+I0R u2Msub7WdP5skHQ== X-Received: by 2002:a05:6214:767:: with SMTP id f7mr31309314qvz.32.1643901797237; 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 Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=trix@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" 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 --- 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 *connector) return -ENOMEM; flags = ast_dp501_read_edid(connector->dev, (u8 *)edid); - if (flags) + if (flags) { ast->dp501_maxclk = ast_get_dp501_max_clk(connector->dev); - else + } else { kfree(edid); + edid = NULL; + } } if (!flags && ast_connector->i2c) edid = drm_get_edid(connector, &ast_connector->i2c->adapter); -- 2.26.3