From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 BE590521231; Wed, 30 Sep 2026 18:33:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790793222; cv=none; b=ouWpBvZJzEzAdxmVIJ1Dw1stka12QHh+iN2TMjDTMrG+wTSRKMaFskbVSp3kyyqeI2lRRqAQ0tQgSr0GijChul7zx/EJhWPTGa3GdIptpfdElMYAnRb/gbcKF36HVOvAQU9fntmi8OPUwuhm/L7s++4eDpzNMzogekX3npWF9a4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790793222; c=relaxed/simple; bh=5fff91DlHi5NpjDOf85EF5YZ3iEbKPdgEg2cU71/dbw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Q+lnnovRrQ3Q27RycQi0hgGbv6s1DLqCMiadkT+n70/MITtRTw2hNzQ/xp75IvT/x5u5OZ144GZ+R6W4xH5bEUG6FJ7F/wz1/BK5haRnlWTZ7RC1z1Z1qwTTWnc3MD19chQWp6twLI0da0Ic0y9f/em9bU+hIDoTroCohg46vpQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lcAQ8Zej; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="lcAQ8Zej" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25E731F00899; Wed, 30 Sep 2026 18:33:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790793220; bh=uChpK+O2IB7590ZBO6F+1dfWGnirmFOKAuNQnPTSbIY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lcAQ8ZejgJJi9F72zH6ADq2WydynX9u6TtuUijm+BBY6idErC4LR9kOzTCVg1XXm2 4ip6WnrDPIK8tL13IpjIsKzoU8JzC7i/VAKnz3DN3PD+/2KSd0et9y6X+VaMbWZ9Yu EkEEhpLtFKTaw4d/YRpQQMjqeAWYpK/7SI44o6lY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Norbert Szetei , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.18 171/395] net: xps: reject an out of range traffic class Date: Wed, 30 Sep 2026 17:27:13 +0200 Message-ID: <20260930152344.361707178@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152340.591469096@linuxfoundation.org> References: <20260930152340.591469096@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-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Norbert Szetei [ Upstream commit 4da3b7b8b50f3e2fde54a4c18a82a8e3f6223910 ] Only the entries below dev->num_tc are valid in dev->tc_to_txq[], and dev->prio_tc_map[] may only name classes below it. netdev_set_num_tc() lowers dev->num_tc without touching either array. netdev_txq_to_tc() walks all TC_MAX_QUEUE slots and netdev_get_prio_tc_map() returns the entry as it stands, so a leftover entry is handed out as a traffic class >= dev->num_tc. Taking that class from netdev_txq_to_tc(), __netif_set_xps_queue() rejects only a negative one and indexes an XPS map sized for dev->num_tc classes: tci = j * num_tc + tc; RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map); attr_map[] holds nr_ids * num_tc entries and j runs over the ids named in the mask, so a class that is not below num_tc pushes tci past the end of the map for the last ids and the store overruns it. Any caller that lowers num_tc leaves such entries behind, and mqprio_destroy() tears down with netdev_set_num_tc(dev, 0) rather than netdev_reset_tc(). After mqprio with 8 classes then 1, tc_to_txq[1..7] still describe txq 1..7. The splat is from an XPS write to txq 2 on a veth with 8 rx queues: attr_map[] has 8 * 1 entries, tci = j + 2, and j == 6 stores one past the end of the 88-byte map: BUG: KASAN: slab-out-of-bounds in __netif_set_xps_queue (net/core/dev.c:2954) Write of size 8 at addr ffff88813016bc58 by task xps_oob/634 __netif_set_xps_queue (net/core/dev.c:2954) xps_rxqs_store (net/core/net-sysfs.c:1880) netdev_queue_attr_store (net/core/net-sysfs.c:1390) Allocated by task 634: __kmalloc_noprof (mm/slub.c:5439) __netif_set_xps_queue (net/core/dev.c:2937) The buggy address is located 0 bytes to the right of allocated 88-byte region [ffff88813016bc00, ffff88813016bc58) Reject a class the map has no room for. Fixes: 184c449f91fe ("net: Add support for XPS with QoS via traffic classes") Signed-off-by: Norbert Szetei Link: https://patch.msgid.link/162DD16F-54C6-444A-9E09-0B8CB3D591F2@doyensec.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/dev.c b/net/core/dev.c index 48983bac5b539..6569605cc666a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2863,7 +2863,7 @@ int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask, dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev; tc = netdev_txq_to_tc(dev, index); - if (tc < 0) + if (tc < 0 || tc >= num_tc) return -EINVAL; } -- 2.53.0