From b62b29e6de6711f5918940aa6ff2bbab6d6af502 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Sun, 10 May 2026 12:29:03 -0700 Subject: [PATCH] net: shaper: enforce singleton NETDEV scope with id 0 The NETDEV scope represents a singleton root shaper in the per-device hierarchy. All code assumes NETDEV shapers have id 0: net_shaper_default_parent() hardcodes parent->id = 0 when returning the NETDEV parent for QUEUE/NODE children, and the UAPI documentation describes NETDEV scope as "the main shaper" (singular, not plural). Make sure we reject non-0 IDs. Fixes: 4b623f9f0f59 ("net-shapers: implement NL get operation") Signed-off-by: Jakub Kicinski Link: https://patch.msgid.link/20260510192904.3987113-10-kuba@kernel.org Signed-off-by: Paolo Abeni --- net/shaper/shaper.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/shaper/shaper.c b/net/shaper/shaper.c index eb049847fed6..4ae3ee6764a0 100644 --- a/net/shaper/shaper.c +++ b/net/shaper/shaper.c @@ -482,6 +482,12 @@ static int net_shaper_parse_handle(const struct nlattr *attr, else if (handle->scope == NET_SHAPER_SCOPE_NODE) id = NET_SHAPER_ID_UNSPEC; + if (id && handle->scope == NET_SHAPER_SCOPE_NETDEV) { + NL_SET_ERR_MSG_ATTR(info->extack, id_attr, + "Netdev scope is a singleton, must use ID 0"); + return -EINVAL; + } + handle->id = id; return 0; }