From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B11703EDAA1; Mon, 20 Apr 2026 13:25:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776691515; cv=none; b=Op73b8vwmJoGjXvuwZm3fyn0R9vJnU98nx+WfLcARNhVYgg28QInFC9ZGyeiRMaM7K/DvTXYDyLoqRXZGBW5iJ3Q6UMXCk6A1FbKyw8aHZGorsEq7k499R9Ki2nSVuvN2QW21aSqcYQFHiZHKmsncyyqEjchmg7RMBMVSS/aa9I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776691515; c=relaxed/simple; bh=aAa37wjp9jNLis7FJ8hKBQTsPEvjboH9hfzGfhPVlc4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ECOxUsNDj8TeckMTbmK5qaCZ7ydwOaTJVb1a9PNnAEQTgd7Yj0q4JknB7ApB856o4jiylYKE8K49MnVrzPy7d1eGVVnUqKoBPJFJp8KDdhagDc5oMFI64zl7Pv77N2WUujgq7H6FSRb16F2+SiRs8clVra7NzyShnUpxWkxEkw8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ulq90t4p; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ulq90t4p" 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 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