From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.20]) (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 E4E9235B64D; Mon, 23 Mar 2026 19:25:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.20 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774293914; cv=none; b=I2rzYFTxzaqkAAgRTw4coqCPS1thzBnRvtTVbF2PodP7xcZ6WdcnWR5F72ecU032sdo/2EKjftedfE0RVlDcpJ6G1YeRGinBb5yuYgo9qSOH522lwBfZd8dXxK28frZzMomg6WAs8hjapwsIs72EPaEut8QkpfOvt2csEbvH0VA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774293914; c=relaxed/simple; bh=xC5R5MNUphmIdYDIVuEk8r8YygGU53qCKz4Rg+iTYsk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=fiRhn7Y1Xf3DQ/SSEhQXY7a3CPon77bD0QdrJsWXTQ4aJsiBSF1SPFMmWe2yZIsW+VsyhAphRn1x3F4UiEQYwwcvoNrseM2g4ie/sscNm6GWoVFYvGbMnyxVR44OLvVz2y3mrOHZaKjvmI4y+4HD4tFeEzEvwpBqHU5CaKjMYms= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=TsMK/B4a; arc=none smtp.client-ip=198.175.65.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="TsMK/B4a" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1774293913; x=1805829913; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=xC5R5MNUphmIdYDIVuEk8r8YygGU53qCKz4Rg+iTYsk=; b=TsMK/B4aZ+81VoC+oC8KThtMtBqkQFzNuoeZcEaruFkGR3ttHtPa7HaS axa3S8Nc7HwSblz3iBJNc8QkzAzrKouBpAnsoO4mQIfBNy8eK6IHQI5Dh ikvbs0bBus1HHH9eZUohig+7xJBSuJlTbdP9kI119AyCTIAD4KjKxcAgp 0JEd498XShOPYdKp4ahrQDOHKThUz/bi01jnhATng8mGsN+ExVAXkEnEA iT84PrYNRS0wvTuODaFa5dRMnFGa2M7E7/8IP1oqIPyeKq+cdKltarjbq Z23eK66YTQu80G6BiMZPABTcqXv/Y8Zuk70o7IQrbmgglG0BVzwL23Cht A==; X-CSE-ConnectionGUID: oXKK1dZcQuuIz5FxZZ7l1w== X-CSE-MsgGUID: o8cjKfmERBWQC2W+LyVTag== X-IronPort-AV: E=McAfee;i="6800,10657,11738"; a="75013307" X-IronPort-AV: E=Sophos;i="6.23,137,1770624000"; d="scan'208";a="75013307" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Mar 2026 12:25:13 -0700 X-CSE-ConnectionGUID: Zre272SXR2CJHmQ+CntO1g== X-CSE-MsgGUID: GEcKIbGGQYOundakmPOpUg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,137,1770624000"; d="scan'208";a="228187875" Received: from boxer.igk.intel.com ([10.102.20.173]) by orviesa003.jf.intel.com with ESMTP; 23 Mar 2026 12:25:10 -0700 From: Maciej Fijalkowski To: netdev@vger.kernel.org Cc: bpf@vger.kernel.org, magnus.karlsson@intel.com, stfomichev@gmail.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, larysa.zaremba@intel.com, aleksander.lobakin@intel.com, bjorn@kernel.org, Maciej Fijalkowski , Stanislav Fomichev Subject: [PATCH v3 net 1/8] xsk: tighten UMEM headroom validation to account for tailroom and min frame Date: Mon, 23 Mar 2026 20:24:50 +0100 Message-Id: <20260323192457.504631-2-maciej.fijalkowski@intel.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20260323192457.504631-1-maciej.fijalkowski@intel.com> References: <20260323192457.504631-1-maciej.fijalkowski@intel.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The current headroom validation in xdp_umem_reg() could leave us with insufficient space dedicated to even receive minimum-sized ethernet frame. Furthermore if multi-buffer would come to play then skb_shared_info stored at the end of XSK frame would be corrupted. HW typically works with 128-aligned sizes so let us provide this value as bare minimum. Multi-buffer setting is known later in the configuration process so besides accounting for 128 bytes, let us also take care of tailroom space upfront. Reviewed-by: Björn Töpel Acked-by: Stanislav Fomichev Fixes: 99e3a236dd43 ("xsk: Add missing check on user supplied headroom size") Signed-off-by: Maciej Fijalkowski --- net/xdp/xdp_umem.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index 066ce07c506d..98c1eacf8c40 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -203,7 +203,8 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) if (!unaligned_chunks && chunks_rem) return -EINVAL; - if (headroom >= chunk_size - XDP_PACKET_HEADROOM) + if (headroom >= chunk_size - XDP_PACKET_HEADROOM - + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) - 128) return -EINVAL; if (mr->flags & XDP_UMEM_TX_METADATA_LEN) { -- 2.43.0