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 56B083F23BF; Wed, 20 May 2026 17:50:24 +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=1779299425; cv=none; b=N3Dez+BwxCOmsAnphmxJnaDKncCa6le4laIzIvCP9VTOD8A5p4zqdnBnju5ZPnTxQSSadw6RUGH0nniSN/cAMGa0vPKdh6mQ46wWy44CHgfU4+imiIQNsJtt2sEPp5JTpkqF4eWUlgSCa3dO54Lll0HFehNXuekokJ2sjZKDprw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299425; c=relaxed/simple; bh=2YNiOURkchvV+4m7XpmvQYs+TEqKHHft4fHry9w0lnY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uF/eo6i+si/kyd+bgqOekYVmuz3v0om4xmQlZwhv63kanidzFYsS4/Vxch1Xw+rwCA8nvmBCjP/rOr1q2po4zJ+8G6l21qkDeks2151eZzBX49BAw6L8OPlQHK4epaYTCv6K8UD6bTvLCWCRLhOlwMlo48mx+edivpma4mZx43c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Ew7cGxC6; 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="Ew7cGxC6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BAE531F000E9; Wed, 20 May 2026 17:50:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779299424; bh=/ETgaT6JWEgAD54VIvxPgnLvw3n47HSgkhV87qk//VI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Ew7cGxC6XHPDPOSLuA+xWjfsnwHL6bEiYXm0JNFRKsQmRbB3hp06ZfDtyPgUmUL86 DYHGDmeKM7fWgj3HDlw8MDBm0go/veaSBB+0bt3D4hOdlHc6gL/8WLLl1P14Qt+O7+ +MZSmGSQDnuo2FTaQRYXey9j2KH/AokrxJbd0PCI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stephen Hemminger , Simon Horman , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.18 768/957] net/sched: netem: validate slot configuration Date: Wed, 20 May 2026 18:20:51 +0200 Message-ID: <20260520162151.218146510@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162134.554764788@linuxfoundation.org> References: <20260520162134.554764788@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stephen Hemminger [ Upstream commit 01801c359a74737b9b1aa28568b60374d857241a ] Reject slot configurations that have no defensible meaning: - negative min_delay or max_delay - min_delay greater than max_delay - negative dist_delay or dist_jitter - negative max_packets or max_bytes Negative or out-of-order delays underflow in get_slot_next(), producing garbage intervals. Negative limits trip the per-slot accounting (packets_left/bytes_left <= 0) on the first packet of every slot, defeating the rate-limiting half of the slot feature. Note that dist_jitter has been silently coerced to its absolute value by get_slot() since the feature was introduced; rejecting negatives here converts that silent coercion into -EINVAL. The abs() can be removed in a follow-up. Fixes: 836af83b54e3 ("netem: support delivering packets in delayed time slots") Signed-off-by: Stephen Hemminger Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260418032027.900913-5-stephen@networkplumber.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/sched/sch_netem.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index 4bf65fcdaff02..41d60e904090d 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -826,6 +826,29 @@ static int get_dist_table(struct disttable **tbl, const struct nlattr *attr) return 0; } +static int validate_slot(const struct nlattr *attr, struct netlink_ext_ack *extack) +{ + const struct tc_netem_slot *c = nla_data(attr); + + if (c->min_delay < 0 || c->max_delay < 0) { + NL_SET_ERR_MSG_ATTR(extack, attr, "negative slot delay"); + return -EINVAL; + } + if (c->min_delay > c->max_delay) { + NL_SET_ERR_MSG_ATTR(extack, attr, "slot min delay greater than max delay"); + return -EINVAL; + } + if (c->dist_delay < 0 || c->dist_jitter < 0) { + NL_SET_ERR_MSG_ATTR(extack, attr, "negative dist delay"); + return -EINVAL; + } + if (c->max_packets < 0 || c->max_bytes < 0) { + NL_SET_ERR_MSG_ATTR(extack, attr, "negative slot limit"); + return -EINVAL; + } + return 0; +} + static void get_slot(struct netem_sched_data *q, const struct nlattr *attr) { const struct tc_netem_slot *c = nla_data(attr); @@ -1039,6 +1062,12 @@ static int netem_change(struct Qdisc *sch, struct nlattr *opt, goto table_free; } + if (tb[TCA_NETEM_SLOT]) { + ret = validate_slot(tb[TCA_NETEM_SLOT], extack); + if (ret) + goto table_free; + } + sch_tree_lock(sch); /* backup q->clg and q->loss_model */ old_clg = q->clg; -- 2.53.0