CVE-2021-47010
CVSS Score
V3.1EPSS Score
v2023.03.01There is a 0.0% chance that this vulnerability will be exploited in the wild within the next 30 days.
Attack Vector Metrics
Impact Metrics
Description
In the Linux kernel, the following vulnerability has been resolved:
net: Only allow init netns to set default tcp cong to a restricted algo
tcp_set_default_congestion_control() is netns-safe in that it writes
to &net->ipv4.tcp_congestion_control, but it also sets
ca->flags |= TCP_CONG_NON_RESTRICTED which is not namespaced.
This has the unintended side-effect of changing the global
net.ipv4.tcp_allowed_congestion_control sysctl, despite the fact that it
is read-only: 97684f0970f6 ("net: Make tcp_allowed_congestion_control
readonly in non-init netns")
Resolve this netns "leak" by only allowing the init netns to set the
default algorithm to one that is restricted. This restriction could be
removed if tcp_allowed_congestion_control were namespace-ified in the
future.
This bug was uncovered with
https://github.com/JonathonReinhart/linux-netns-sysctl-verify