net/sched: ets: clamp quantum in parse and fallback paths
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.2%
exploitation probability
0.2%top 95% of all CVEs
observed exploitation
nono source reports it
In the Linux kernel, the following vulnerability has been resolved:
net/sched: ets: clamp quantum in parse and fallback paths
ets_qdisc_change() falls back to psched_mtu() with no floor for bands
without an explicit quantum. With a crafted size table qdisc_pkt_len
reaches ~2 GiB, so a zero psched_mtu on a headerless device makes the
deficit-refill loop spin under the qdisc lock.
Move the floor into ets_quantum_parse() so explicitly configured quanta
are also clamped to [256, 1<<20], not just the fallback path.
Conditions to recreate the bug:
CONFIG_NET_SCH_ETS=y. Requires CAP_NET_ADMIN (namespace-local via
unshare -Urn suffices).
tc qdisc add dev dummy0 root ets bands 3 strict 2 quanta 1 1
Affected products
Linux · Linux