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 2CFF93F4DF4; Wed, 20 May 2026 17:50:32 +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=1779299433; cv=none; b=CkuZ8Vzb24EEsxKM8ntQoHiDaE47hqpYNx4pI1CMJQ7iEcMZNt9EelW7R7qEvX+kEHtiFPc5jLynTsojQJnNnErVb1WDzEz/lU1zfFByNFlQQtrV18PEb4HzVWvuNhJLxEpY1ze/I+kpXOK6hcK0xGw7mVy17+UkTAXSJltY0Jg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299433; c=relaxed/simple; bh=g+G2Q62K3fre8+ZvT6ANeayCzIHyK60RN7U/hjzFMdE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IiuS3Ji13pBRasQMmZrNg/tT+LD6lefm0yzADalcrb4w0SQToDmBOv1EE63oxzectavJwlTsGyfrJE0+rL1m5oXJHTp696PiytkyRzzoGd6QpNpSpeP4VTXPgB7GVRMpcF9n4HhgEaSgnMsqfdOyGZrdLt6fnILePCUav6fnrQc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=b+BAJl5A; 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="b+BAJl5A" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 939FA1F000E9; Wed, 20 May 2026 17:50:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779299432; bh=oRRF0aPbxAPkra9Jdk3xzFm9jlBoUMrAWy0n8ViWyQ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=b+BAJl5ANPKv/zsBpLqFizoefF5RvUOCTfVAssqj0bstvrcQyc69+By7CIkaTDpTV 10TEq3ngZouHo6ZU4AfbpvmM9wRfD4lRb14YXZq07NXmw9vHyGZOiIfK7JWTQu2KiQ vaDQNIAcme0ao00UVLKLvbpX8/I4LwBxw6XJdAYY= 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 6.18 770/957] net/sched: netem: check for negative latency and jitter Date: Wed, 20 May 2026 18:20:53 +0200 Message-ID: <20260520162151.262084830@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 90be9fedb218ee95a1cf59050d1306fbfb0e8b87 ] Reject requests with negative latency or jitter. A negative value added to current timestamp (u64) wraps to an enormous time_to_send, disabling dequeue. The original UAPI used u32 for these values; the conversion to 64-bit time values via TCA_NETEM_LATENCY64 and TCA_NETEM_JITTER64 allowed signed values to reach the kernel without validation. Jitter is already silently clamped by an abs() in netem_change(); that abs() can be removed in a follow-up once this rejection is in place. Fixes: 99803171ef04 ("netem: add uapi to express delay and jitter in nanoseconds") Signed-off-by: Stephen Hemminger Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260418032027.900913-7-stephen@networkplumber.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/sched/sch_netem.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index 6e221bdfb3871..47db6da905c58 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -825,6 +825,16 @@ static int get_dist_table(struct disttable **tbl, const struct nlattr *attr) return 0; } +static int validate_time(const struct nlattr *attr, const char *name, + struct netlink_ext_ack *extack) +{ + if (nla_get_s64(attr) < 0) { + NL_SET_ERR_MSG_ATTR_FMT(extack, attr, "negative %s", name); + return -EINVAL; + } + return 0; +} + static int validate_slot(const struct nlattr *attr, struct netlink_ext_ack *extack) { const struct tc_netem_slot *c = nla_data(attr); @@ -1067,6 +1077,18 @@ static int netem_change(struct Qdisc *sch, struct nlattr *opt, goto table_free; } + if (tb[TCA_NETEM_LATENCY64]) { + ret = validate_time(tb[TCA_NETEM_LATENCY64], "latency", extack); + if (ret) + goto table_free; + } + + if (tb[TCA_NETEM_JITTER64]) { + ret = validate_time(tb[TCA_NETEM_JITTER64], "jitter", extack); + if (ret) + goto table_free; + } + sch_tree_lock(sch); /* backup q->clg and q->loss_model */ old_clg = q->clg; -- 2.53.0