From nobody Wed Apr 8 15:52:32 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 9081AC38A02 for ; Sun, 30 Oct 2022 15:45:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229849AbiJ3PpC (ORCPT ); Sun, 30 Oct 2022 11:45:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229770AbiJ3Pox (ORCPT ); Sun, 30 Oct 2022 11:44:53 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07A03B1DE for ; Sun, 30 Oct 2022 08:44:53 -0700 (PDT) Received: from dimapc.. (unknown [109.252.112.196]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: dmitry.osipenko) by madras.collabora.co.uk (Postfix) with ESMTPSA id E00E066022A2; Sun, 30 Oct 2022 15:44:50 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1667144691; bh=Jr+CDx/FOmbAS4EXsPeToboJf/vzEdDZoQONhOc44DE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D77hkyxoateNQYLF7wJaHR+9csvedoBuzF1VEUTMenUkMjtdSeyXUAhgE0j4RXuLL Linbwa8HPzpUigLIVoxs7LY25ZnDHWu77L1e1Q7YGyXwmOKgD3BcSzOhrRNW06qo8h vIMEKpXsMe8QU+z9CDPFk7/fR+FFtgzo3b4+FJjHQYU9K1kXH8ISUBV8sOjaF86c1g oPB4Zkj4zO4tGmixIgmZ0m4jNShlzyv6vRfkWt4KlbW+uX+eJypQ916ceOZdx6DhKc dbOzHIpE1tWqNwSK2G/EjpcU6QwFq2DrhD7r7oTmaWUaCYVeTLqy3SkZoLn2Oi//WB i4qutZJMPkWVA== From: Dmitry Osipenko To: Maarten Lankhorst , Maxime Ripard , Sumit Semwal , Thomas Zimmermann , =?UTF-8?q?Christian=20K=C3=B6nig?= , David Airlie , Daniel Vetter , noralf@tronnes.org, Dan Carpenter Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/2] drm/client: Prevent NULL dereference in drm_client_buffer_delete() Date: Sun, 30 Oct 2022 18:44:12 +0300 Message-Id: <20221030154412.8320-3-dmitry.osipenko@collabora.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221030154412.8320-1-dmitry.osipenko@collabora.com> References: <20221030154412.8320-1-dmitry.osipenko@collabora.com> 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" The drm_gem_vunmap() will crash with a NULL dereference if the passed object pointer is NULL. It wasn't a problem before we added the locking support to drm_gem_vunmap function because the mapping argument was always NULL together with the object. Make drm_client_buffer_delete() to check whether GEM is NULL before trying to unmap the GEM, it will happen on framebuffer creation error. Reported-by: Dan Carpenter Link: https://lore.kernel.org/dri-devel/Y1kFEGxT8MVlf32V@kili/ Fixes: 79e2cf2e7a19 ("drm/gem: Take reservation lock for vmap/vunmap operat= ions") Signed-off-by: Dmitry Osipenko Reviewed-by: Christian K=C3=B6nig --- drivers/gpu/drm/drm_client.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c index 38e1be991caa..fd67efe37c63 100644 --- a/drivers/gpu/drm/drm_client.c +++ b/drivers/gpu/drm/drm_client.c @@ -235,10 +235,10 @@ static void drm_client_buffer_delete(struct drm_clien= t_buffer *buffer) { struct drm_device *dev =3D buffer->client->dev; =20 - drm_gem_vunmap_unlocked(buffer->gem, &buffer->map); - - if (buffer->gem) + if (buffer->gem) { + drm_gem_vunmap_unlocked(buffer->gem, &buffer->map); drm_gem_object_put(buffer->gem); + } =20 if (buffer->handle) drm_mode_destroy_dumb(dev, buffer->handle, buffer->client->file); --=20 2.37.3