From patchwork Mon Nov 4 19:10:21 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sherry Yang X-Patchwork-Id: 13861857 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 916A7D1BDE3 for ; Mon, 4 Nov 2024 19:10:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1C15510E06C; Mon, 4 Nov 2024 19:10:48 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=oracle.com header.i=@oracle.com header.b="d2TFOJ1B"; dkim-atps=neutral Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9194210E06C; Mon, 4 Nov 2024 19:10:46 +0000 (UTC) Received: from pps.filterd (m0246627.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 4A4IMVM6004434; Mon, 4 Nov 2024 19:10:26 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-transfer-encoding:date:from:message-id:mime-version :subject:to; s=corp-2023-11-20; bh=4ZZRS8dHCjLH4dXy/hPA0VAA1ekeT 9riEc6CLiyfZrU=; b=d2TFOJ1B0J47+aoYEBQYYGFfDHArARYLoutE9RXCHBgik hJw9RH3bLFeYBRR8fx86HMUWvuIecGJmmU2Py48bngEIHm5w38h++PInZFr+bhS8 WFGCDvp7Q/1DVH0CErjpd0fQC4nVM+7fUTOv9D5TrA1T2zL+Kt5fnV1ssPKeiBPB 6ZefiK8H9uYqhUM+VZPv1IQTvVgSCKtuNHV/KU8q/CVjJFLLcnkVf+Lrk6qD4UOl J+dE1t2s6C4BjvdDY/mw0I5vRj6u1clyJHp7S5pzMZ3AQ8hewXaILl7VWEdsDgSg W+NAAVArFI25WDUIaDrhqI04Src7Errn3JGXJP5NQ== Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.appoci.oracle.com [147.154.18.20]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 42nanyundg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 04 Nov 2024 19:10:26 +0000 (GMT) Received: from pps.filterd (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 4A4Hu8Ma036171; Mon, 4 Nov 2024 19:10:25 GMT Received: from pps.reinject (localhost [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 42nahcf29j-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 04 Nov 2024 19:10:24 +0000 Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 4A4JAOGu013414; Mon, 4 Nov 2024 19:10:24 GMT Received: from ca-dev112.us.oracle.com (ca-dev112.us.oracle.com [10.129.136.47]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTP id 42nahcf28e-1; Mon, 04 Nov 2024 19:10:24 +0000 From: Sherry Yang To: stable@vger.kernel.org, sashal@kernel.org, gregkh@linuxfoundation.org Cc: sherry.yang@oracle.com, jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com, airlied@linux.ie, daniel@ffwll.ch, tvrtko.ursulin@intel.com, robdclark@chromium.org, chentao@kylinos.cn, chris@chris-wilson.co.uk, mika.kuoppala@linux.intel.com, jason@jlekstrand.net, aravind.iddamsetty@intel.com, umesh.nerlige.ramappa@intel.com, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH 5.15.y] drm/i915: Fix potential context UAFs Date: Mon, 4 Nov 2024 11:10:21 -0800 Message-ID: <20241104191021.3334875-1-sherry.yang@oracle.com> X-Mailer: git-send-email 2.46.0 MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1057,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-11-04_17,2024-11-04_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 spamscore=0 mlxlogscore=999 mlxscore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2409260000 definitions=main-2411040157 X-Proofpoint-ORIG-GUID: bYvtKvEXdYGJo-raSa0RreUwVVwTSiDS X-Proofpoint-GUID: bYvtKvEXdYGJo-raSa0RreUwVVwTSiDS X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Rob Clark commit afce71ff6daa9c0f852df0727fe32c6fb107f0fa upstream. gem_context_register() makes the context visible to userspace, and which point a separate thread can trigger the I915_GEM_CONTEXT_DESTROY ioctl. So we need to ensure that nothing uses the ctx ptr after this. And we need to ensure that adding the ctx to the xarray is the *last* thing that gem_context_register() does with the ctx pointer. Signed-off-by: Rob Clark Fixes: eb4dedae920a ("drm/i915/gem: Delay tracking the GEM context until it is registered") Fixes: a4c1cdd34e2c ("drm/i915/gem: Delay context creation (v3)") Fixes: 49bd54b390c2 ("drm/i915: Track all user contexts per client") Cc: # v5.10+ Reviewed-by: Tvrtko Ursulin Reviewed-by: Andi Shyti [tursulin: Stable and fixes tags add/tidy.] Signed-off-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20230103234948.1218393-1-robdclark@gmail.com (cherry picked from commit bed4b455cf5374e68879be56971c1da563bcd90c) Signed-off-by: Rodrigo Vivi Signed-off-by: Greg Kroah-Hartman [Sherry: bp to fix CVE-2023-52913, ignore context conflicts due to missing commit 49bd54b390c2 "drm/i915: Track all user contexts per client")] Signed-off-by: Sherry Yang --- drivers/gpu/drm/i915/gem/i915_gem_context.c | 24 +++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c index 0eb4a0739fa2..0a7c4548b77f 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c @@ -1436,6 +1436,10 @@ void i915_gem_init__contexts(struct drm_i915_private *i915) init_contexts(&i915->gem.contexts); } +/* + * Note that this implicitly consumes the ctx reference, by placing + * the ctx in the context_xa. + */ static void gem_context_register(struct i915_gem_context *ctx, struct drm_i915_file_private *fpriv, u32 id) @@ -1449,13 +1453,13 @@ static void gem_context_register(struct i915_gem_context *ctx, snprintf(ctx->name, sizeof(ctx->name), "%s[%d]", current->comm, pid_nr(ctx->pid)); - /* And finally expose ourselves to userspace via the idr */ - old = xa_store(&fpriv->context_xa, id, ctx, GFP_KERNEL); - WARN_ON(old); - spin_lock(&i915->gem.contexts.lock); list_add_tail(&ctx->link, &i915->gem.contexts.list); spin_unlock(&i915->gem.contexts.lock); + + /* And finally expose ourselves to userspace via the idr */ + old = xa_store(&fpriv->context_xa, id, ctx, GFP_KERNEL); + WARN_ON(old); } int i915_gem_context_open(struct drm_i915_private *i915, @@ -1932,14 +1936,22 @@ finalize_create_context_locked(struct drm_i915_file_private *file_priv, if (IS_ERR(ctx)) return ctx; + /* + * One for the xarray and one for the caller. We need to grab + * the reference *prior* to making the ctx visble to userspace + * in gem_context_register(), as at any point after that + * userspace can try to race us with another thread destroying + * the context under our feet. + */ + i915_gem_context_get(ctx); + gem_context_register(ctx, file_priv, id); old = xa_erase(&file_priv->proto_context_xa, id); GEM_BUG_ON(old != pc); proto_context_close(pc); - /* One for the xarray and one for the caller */ - return i915_gem_context_get(ctx); + return ctx; } struct i915_gem_context *