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 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 1EEA7F588C2 for ; Mon, 20 Apr 2026 13:25:17 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 819F210E60D; Mon, 20 Apr 2026 13:25:16 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="ulq90t4p"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id D3A4810E60E for ; Mon, 20 Apr 2026 13:25:15 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id B3E1943D37; Mon, 20 Apr 2026 13:25:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2AF26C2BCB4; Mon, 20 Apr 2026 13:25:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776691515; bh=aAa37wjp9jNLis7FJ8hKBQTsPEvjboH9hfzGfhPVlc4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ulq90t4p8TP055U5GKAZcSdiFezZTxdarUke4u/glSMjPHt8Sg2pcxiUgVOzsxNhd lPdrXttVwX2Srx8gJgqR/rxNAxUGPqyPq/azmT0c5HgCJ5v86118ZPqzagIvB5xuNn IgFTvE46sIicscAoKcNqnhfz6XVA9ErzlpLLoQL+qrsMk3AFQhl1/Tuze8EwK8smNu Bb6IK81B9KmQLnEypZfjoLB12wz7/4zK81gl9i6I6qFETMf5inOu0MP7faugU1mNN0 AzjF/qOC6wJifWuvtLQvKGxSrt+xL/MSzEHmPdvxFP1XCp3oucnEnPuZ5ovhSaM1zT VYZuFWvUiHf5w== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: =?UTF-8?q?Ma=C3=ADra=20Canal?= , Melissa Wen , Sasha Levin , mripard@kernel.org, dave.stevenson@raspberrypi.com, maarten.lankhorst@linux.intel.com, tzimmermann@suse.de, airlied@gmail.com, simona@ffwll.ch, eric@anholt.net, bbrezillon@kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH AUTOSEL 6.18] drm/vc4: Protect madv read in vc4_gem_object_mmap() with madv_lock Date: Mon, 20 Apr 2026 09:17:49 -0400 Message-ID: <20260420132314.1023554-75-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260420132314.1023554-1-sashal@kernel.org> References: <20260420132314.1023554-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.18.23 Content-Transfer-Encoding: 8bit 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: Maíra Canal [ Upstream commit 338c56050d8e892604da97f67bfa8cc4015a955f ] The mmap callback reads bo->madv without holding madv_lock, racing with concurrent DRM_IOCTL_VC4_GEM_MADVISE calls that modify the field under the same lock. Add the missing locking to prevent the data race. Fixes: b9f19259b84d ("drm/vc4: Add the DRM_IOCTL_VC4_GEM_MADVISE ioctl") Reviewed-by: Melissa Wen Link: https://patch.msgid.link/20260330-vc4-misc-fixes-v1-4-92defc940a29@igalia.com Signed-off-by: Maíra Canal Signed-off-by: Sasha Levin --- LLM Generated explanations, may be completely bogus: Error: Failed to generate final synthesis drivers/gpu/drm/vc4/vc4_bo.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/vc4/vc4_bo.c b/drivers/gpu/drm/vc4/vc4_bo.c index 4aaa587be3a5e..a1efda9c39f92 100644 --- a/drivers/gpu/drm/vc4/vc4_bo.c +++ b/drivers/gpu/drm/vc4/vc4_bo.c @@ -738,12 +738,15 @@ static int vc4_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct return -EINVAL; } + mutex_lock(&bo->madv_lock); if (bo->madv != VC4_MADV_WILLNEED) { DRM_DEBUG("mmapping of %s BO not allowed\n", bo->madv == VC4_MADV_DONTNEED ? "purgeable" : "purged"); + mutex_unlock(&bo->madv_lock); return -EINVAL; } + mutex_unlock(&bo->madv_lock); return drm_gem_dma_mmap(&bo->base, vma); } -- 2.53.0