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 081E5D185DA for ; Thu, 8 Jan 2026 11:34:05 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 577F810E6F4; Thu, 8 Jan 2026 11:34:03 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="Dh/yvgFP"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1CFC110E33C; Thu, 8 Jan 2026 11:34:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1767872041; x=1799408041; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=jc56LgLjYKnVgX0BKLfblpQNGyqAU34pv/3BOpItWY8=; b=Dh/yvgFPD5mnAwWWJ+F24o137+SGE7EgEVQlpjDTBHReIYTi1O9pLtRI BPpMwOdUFDDhbRjc3ThqZuAyw/Oe57DC2VkG5ror9z69LipeWw6IETae4 wxTVj00oW2c6W/sY8c+mikeZYXMPc9SPyY5hQBq9J8/hrN5rpLGuS6tLP cA00hCau0Xrjys8LJCrSAUP0g9hmqf+HICaaGNVu/56zjiaPxkejrwS+Z tE4ctPP/RTgDxRUJ5ULrKvLjk2q2tiS6SXiXlPzjXIr2zMzmJdbggwRRd FEVlX+VbLSHfbbiYvT+EuwFiyS6xsiRfTSJC1h9n/iDwyZN3UGzr+4Xwb Q==; X-CSE-ConnectionGUID: L4Zv38F4Qp+vFkpqxjIXRA== X-CSE-MsgGUID: 43EamcM3TVKf8smS38K3Mg== X-IronPort-AV: E=McAfee;i="6800,10657,11664"; a="71824650" X-IronPort-AV: E=Sophos;i="6.21,210,1763452800"; d="scan'208";a="71824650" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jan 2026 03:34:01 -0800 X-CSE-ConnectionGUID: CQLjPiwZRGyRJhYvOefAlQ== X-CSE-MsgGUID: qWNH+cnaRsCmI98m6tEeJA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,210,1763452800"; d="scan'208";a="208024040" Received: from yadavs-z690i-a-ultra-plus.iind.intel.com ([10.190.216.90]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jan 2026 03:33:59 -0800 From: Sanjay Yadav To: dri-devel@lists.freedesktop.org Cc: intel-xe@lists.freedesktop.org, stable@vger.kernel.org, =?UTF-8?q?Christian=20K=C3=B6nig?= , Arunpravin Paneer Selvam , Matthew Auld Subject: [PATCH v2 1/2] drm/buddy: Prevent BUG_ON by validating rounded allocation Date: Thu, 8 Jan 2026 17:02:29 +0530 Message-ID: <20260108113227.2101872-5-sanjay.kumar.yadav@intel.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260108113227.2101872-4-sanjay.kumar.yadav@intel.com> References: <20260108113227.2101872-4-sanjay.kumar.yadav@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" When DRM_BUDDY_CONTIGUOUS_ALLOCATION is set, the requested size is rounded up to the next power-of-two via roundup_pow_of_two(). Similarly, for non-contiguous allocations with large min_block_size, the size is aligned up via round_up(). Both operations can produce a rounded size that exceeds mm->size, which later triggers BUG_ON(order > mm->max_order). Example scenarios: - 9G CONTIGUOUS allocation on 10G VRAM memory: roundup_pow_of_two(9G) = 16G > 10G - 9G allocation with 8G min_block_size on 10G VRAM memory: round_up(9G, 8G) = 16G > 10G Fix this by checking the rounded size against mm->size. For non-contiguous or range allocations where size > mm->size is invalid, return -EINVAL immediately. For contiguous allocations without range restrictions, allow the request to fall through to the existing __alloc_contig_try_harder() fallback. This ensures invalid user input returns an error or uses the fallback path instead of hitting BUG_ON. v2: (Matt A) - Add Fixes, Cc stable, and Closes tags for context Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6712 Fixes: 0a1844bf0b53 ("drm/buddy: Improve contiguous memory allocation") Cc: # v6.7+ Cc: Christian König Cc: Arunpravin Paneer Selvam Suggested-by: Matthew Auld Signed-off-by: Sanjay Yadav Reviewed-by: Matthew Auld Reviewed-by: Arunpravin Paneer Selvam --- drivers/gpu/drm/drm_buddy.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c index 2f279b46bd2c..5141348fc6c9 100644 --- a/drivers/gpu/drm/drm_buddy.c +++ b/drivers/gpu/drm/drm_buddy.c @@ -1155,6 +1155,15 @@ int drm_buddy_alloc_blocks(struct drm_buddy *mm, order = fls(pages) - 1; min_order = ilog2(min_block_size) - ilog2(mm->chunk_size); + if (order > mm->max_order || size > mm->size) { + if ((flags & DRM_BUDDY_CONTIGUOUS_ALLOCATION) && + !(flags & DRM_BUDDY_RANGE_ALLOCATION)) + return __alloc_contig_try_harder(mm, original_size, + original_min_size, blocks); + + return -EINVAL; + } + do { order = min(order, (unsigned int)fls(pages) - 1); BUG_ON(order > mm->max_order); -- 2.52.0