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 585C035E953; Thu, 2 Apr 2026 15:50:33 +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=1775145034; cv=none; b=YpKwYi2c9vi8LhX7qT2CtPSpFbrakrfreIN2u+4n22M4/8B6bet02yQzY+vWLFJjKUcC89b6IdFDm1d40CAGoVQy5WNlBQVEgIC7w4Rn7N1kBXDHvpcZhn12akzbKlzdFhlzhQn/LGIhIEwGTrKKdDLZr7Wu3lIcv7rY/8I/na0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775145034; c=relaxed/simple; bh=zC9NdznL7SwECGii6q9vWpfRFEHrBpEzALMlj8xuFmM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=u7ayjs39fVD25+oA0bjrD25go3OrEZaIav8rGigUxJWdzrVbRtCoyCwhD9db3avfeJmvySECOR1BaMQBJP0OL73vGPZjA8vC/ExFiwXhQPG6wio5Eo+aFjvehvBgokiA8mD+rNZwkMNPN0rzr4qj7H7+oW1txnAcdDlw4pcQRQc= 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=BlU96qds; 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="BlU96qds" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1775145034; x=1806681034; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=zC9NdznL7SwECGii6q9vWpfRFEHrBpEzALMlj8xuFmM=; b=BlU96qdsVyx7b23WQvpZSkz9pkftZDvHeNGq0gFIesiZP9cK/kufo07I D+/BORJoq9yz3Z/aoitN/aHv6Y2WFhGBK6a+Cu7p1lAM8T8ubMFk6Wg2V vco+z9K/cLJ74WaRkWs8Tg7uml4HpO1+buQGkIesugLhtBkOJsjT3jP1a ICpsz/LnsTH0MVDTGu8hbknwU6yjFzjmfgW7NOBHvRpV309b5MBv1rxQm FHYLKOe897uZMEDUD3XvzBQBFPZ7Ljx0qwoF6sRqc6bmX/QuYZSWPZ4We 0hlsx1L9ZaJOp5r+PNxeXqImZZu/Rz5wGOfImulqJwQBFjE1hY8Th3Fqw A==; X-CSE-ConnectionGUID: WciEjiLsSLyApjtub2TU9w== X-CSE-MsgGUID: OYTbYKXnTpWL6ZVMb74yFw== X-IronPort-AV: E=McAfee;i="6800,10657,11747"; a="75927960" X-IronPort-AV: E=Sophos;i="6.23,156,1770624000"; d="scan'208";a="75927960" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Apr 2026 08:50:33 -0700 X-CSE-ConnectionGUID: J+InQzxSSVSKedTNLrkoCA== X-CSE-MsgGUID: TUfszvUQQWmO5UXZ2Q6mOg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,156,1770624000"; d="scan'208";a="224157545" Received: from boxer.igk.intel.com ([10.102.20.173]) by fmviesa008.fm.intel.com with ESMTP; 02 Apr 2026 08:50:30 -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 v6 net 1/8] xsk: tighten UMEM headroom validation to account for tailroom and min frame Date: Thu, 2 Apr 2026 17:49:51 +0200 Message-Id: <20260402154958.562179-2-maciej.fijalkowski@intel.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20260402154958.562179-1-maciej.fijalkowski@intel.com> References: <20260402154958.562179-1-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..58da2f4f4397 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