Creating FDB entries is possible from a non-initial user namespace when having CAP_NET_ADMIN, yet, when deleting FDB entries, processes receive an EPERM because the capability is always checked against the initial user namespace. This restricts the FDB management from unprivileged containers. Drop the netlink_capable check in rtnl_fdb_del as it was originally dropped in c5c351088ae7 and reintroduced in 1690be63a27b without intention. This patch was tested using a container on GyroidOS, where it was possible to delete FDB entries from an unprivileged user namespace and private network namespace. Fixes: 1690be63a27b ("bridge: Add vlan support to static neighbors") Reviewed-by: Michael Weiß Tested-by: Harshal Gohel Signed-off-by: Johannes Wiesböck --- v2: - completely drop the capability check in favor of changing to netlink_net_capable - describe intended behavior already possible for adding FDB entries v1: https://lore.kernel.org/all/20250923082153.60030-1-johannes.wiesboeck@aisec.fraunhofer.de/ --- net/core/rtnetlink.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 8040ff7c356e4..576d5ec3bb364 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -4715,9 +4715,6 @@ static int rtnl_fdb_del(struct sk_buff *skb, struct nlmsghdr *nlh, int err; u16 vid; - if (!netlink_capable(skb, CAP_NET_ADMIN)) - return -EPERM; - if (!del_bulk) { err = nlmsg_parse_deprecated(nlh, sizeof(*ndm), tb, NDA_MAX, NULL, extack); -- 2.51.0