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 5F2CC33F8B7; Mon, 20 Apr 2026 15:51:01 +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=1776700261; cv=none; b=fl+C2gLF7hKKxWErAinQklYOrTk/Ngj8I7+/LpcOLfwqHQCkaqki/E1ZMbGl+7SKgUxmqcrTb1sZCSU4jKYag/AIRhOQMfeRRk+TaIL4X99seXvnTtaPqnRm1Corplc0k6yas0O+lNbzYOxq+L9PFLA91/5erBLBvSMD6VoxiZA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776700261; c=relaxed/simple; bh=824ZXpxRoSENmZqkv2Wg2lYCuCDIDA7IQTUhrWfJIGs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=mtw1YSUMmTbCAnSQe98R8Qa5MDTUYKlgYDKQCliCxXik+1n+BZ8JMMO+O8bWMLkFY29YSiTOWhAvu1YWvKKnvR3Xuz8bFeQNJpW69u4Ti15mHEtUMIt/bWRzlvzI07NV8+qo0wUhtBaGWnOUSXukF3i2V79l5H2Cp1GYvN7Lae4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XBfhu8I8; 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="XBfhu8I8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EAA37C19425; Mon, 20 Apr 2026 15:51:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776700261; bh=824ZXpxRoSENmZqkv2Wg2lYCuCDIDA7IQTUhrWfJIGs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XBfhu8I8Rs21f3FuXObM5cvMKjGvFfSu18z3WNBfpNrW1FZ29wI3VaNyFjjTWAZus dZksH9uM/VdjrOmUL/eSE8yZDA4eRmLB8qgukoKTaq4mM3KSLj7zphiSVG16LxfGHw R6oYcHic+2UDY0HFYb4Mb1EwhPqUwwSYS5Q+dOE0= 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 6.19 102/220] xsk: tighten UMEM headroom validation to account for tailroom and min frame Date: Mon, 20 Apr 2026 17:40:43 +0200 Message-ID: <20260420153937.708508266@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260420153934.013228280@linuxfoundation.org> References: <20260420153934.013228280@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 6.19-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