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 D76E72D0606; Thu, 12 Mar 2026 20:24:34 +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=1773347074; cv=none; b=G1o/z29k4PVE00JIDE8xQNer9d9N1E+/HTM+lD9ff25UtxoIkU00EdIibjifwdAiiJesyojZZnYfVdh5bjab9tVU/ShQtjJT2DKTP3QKg6S9KDkvgtFY9pHv90+XRi21J57gvHhwEM3BVEx8kfi/pMmvdiYi59BCoKiFB+LK/W4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773347074; c=relaxed/simple; bh=T9kEJNonYVDLJr/jYYgITPEukiPgXL6MSqAFcXHLgFk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YUQnb/GvMXpx2tGukiItlY4AGXiKJrElu7aqdvh2ec1frMEB2Ddqh5soCSPgaS2MeaWOlQbqYOMTIO84whI+ANn7xl0zVosYFjRx+3B8RtvnwdXHVFL5Ynv/9R5m1hOTI/A0RLXs3dD5GJ/0u2qCcp0nFa3Fh9UpsPIalK4mp9s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=O0BM+1RH; 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="O0BM+1RH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3415EC4CEF7; Thu, 12 Mar 2026 20:24:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1773347074; bh=T9kEJNonYVDLJr/jYYgITPEukiPgXL6MSqAFcXHLgFk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=O0BM+1RHjbyFHlu2oYfuPRJJcJ33WAB6jM7wyXZgFvEkFO1EhUO3AzNy5VG+F4xuY qBb8lz+M4+PvEkLjpaGyZLPfsKu6OBngoVgb2BE74F4harc8pmJ57xBp9eewRnK2SZ S34SvK2OBVqjCmyQ7qnBH46RJt4VtNK2o3XZsiNo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Nikhil P. Rao" , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12 188/265] xsk: Fix zero-copy AF_XDP fragment drop Date: Thu, 12 Mar 2026 21:09:35 +0100 Message-ID: <20260312201025.104015013@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260312201018.128816016@linuxfoundation.org> References: <20260312201018.128816016@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nikhil P. Rao [ Upstream commit f7387d6579d65efd490a864254101cb665f2e7a7 ] AF_XDP should ensure that only a complete packet is sent to application. In the zero-copy case, if the Rx queue gets full as fragments are being enqueued, the remaining fragments are dropped. For the multi-buffer case, add a check to ensure that the Rx queue has enough space for all fragments of a packet before starting to enqueue them. Fixes: 24ea50127ecf ("xsk: support mbuf on ZC RX") Signed-off-by: Nikhil P. Rao Link: https://patch.msgid.link/20260225000456.107806-3-nikhil.rao@amd.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/xdp/xsk.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 158c92918bc3a..ed1aeaded9be7 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -159,25 +159,31 @@ static int xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) struct xdp_buff_xsk *pos, *tmp; struct list_head *xskb_list; u32 contd = 0; + u32 num_desc; int err; - if (frags) - contd = XDP_PKT_CONTD; + if (likely(!frags)) { + err = __xsk_rcv_zc(xs, xskb, len, contd); + if (err) + goto err; + return 0; + } - err = __xsk_rcv_zc(xs, xskb, len, contd); - if (err) + contd = XDP_PKT_CONTD; + num_desc = xdp_get_shared_info_from_buff(xdp)->nr_frags + 1; + if (xskq_prod_nb_free(xs->rx, num_desc) < num_desc) { + xs->rx_queue_full++; + err = -ENOBUFS; goto err; - if (likely(!frags)) - return 0; + } + __xsk_rcv_zc(xs, xskb, len, contd); xskb_list = &xskb->pool->xskb_list; list_for_each_entry_safe(pos, tmp, xskb_list, list_node) { if (list_is_singular(xskb_list)) contd = 0; len = pos->xdp.data_end - pos->xdp.data; - err = __xsk_rcv_zc(xs, pos, len, contd); - if (err) - goto err; + __xsk_rcv_zc(xs, pos, len, contd); list_del_init(&pos->list_node); } -- 2.51.0