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 D5BB232E696; Mon, 20 Apr 2026 16:00:59 +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=1776700859; cv=none; b=ct43MQ9RoWRHq3aHBoeVzA7JDDgHLsU8iQ5aFHP0lHvaAeWAfmxZC6ihzcYvURfcmRB78KpVAw8uulnzPopLhpf9dmmeJguYpkE7ACr1l+NrYD2Ba4nUiLcPlw9icmAoK8ESYg0np8HcRa1bm9hNgbxHGwGNLFgwb/3sHjQjrJ0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776700859; c=relaxed/simple; bh=snOFseOE/OfJ0J7/DD5CZKyzg1yhvgj9RV9ZMdE5VOY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=aLMnmnVTYSDr0qp1ElLam0WNijB0jOIWH8jcPbANDLtfnTVN7IyjTuy4BBBqqc4PDAXwyamhxQjiIuXu1Ozn4JjpKaq04xZk9WbMEbDmZNBQELp6ZZNJNcSAGr//WFSDFnv4kG5f2xfwrv04Qf5FppcWdbkcaa7FOzqUYVT9oEE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Y0izfqBz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Y0izfqBz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2FF22C19425; Mon, 20 Apr 2026 16:00:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776700859; bh=snOFseOE/OfJ0J7/DD5CZKyzg1yhvgj9RV9ZMdE5VOY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y0izfqBzzOmCdYcnoDIf+eKLvyteom57oxFd+6+6ZzL9TQWVqgx5CkeQCfjYjA1cg 24fLMSxZFgWSA9kHdmA+LscDuofuHY7Cmz3oD1u8cKHA86+ojMciTUbsY3JSwLUg6y v14aqfNAzk8H5wLHJM2apSl9VB2e/8s6ySYDblEI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Stanislav Fomichev , Maciej Fijalkowski , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.18 088/198] xsk: tighten UMEM headroom validation to account for tailroom and min frame Date: Mon, 20 Apr 2026 17:41:07 +0200 Message-ID: <20260420153938.776212279@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260420153935.605963767@linuxfoundation.org> References: <20260420153935.605963767@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maciej Fijalkowski [ Upstream commit a315e022a72d95ef5f1d4e58e903cb492b0ad931 ] 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 Link: https://patch.msgid.link/20260402154958.562179-2-maciej.fijalkowski@intel.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- 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 9f76ca591d54f..9ec7bd948acc7 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -202,7 +202,8 @@ 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) { -- 2.53.0