CVE-2026-98317

In the Linux kernel, the following vulnerability has been resolved:

neighbour: Enforce min/max to NDTPA INTERVAL PROBE TIME MS.

NDTPA INTERVAL PROBE TIME MS sets .type and .min but misses .validation type, so no validation is applied:

--json '{"name": "arp cache", "parms": {"interval-probe-time-ms": 0}}'

jq '.[] | select(.name == "arp cache" and has("config")) | .parms["interval-probe-time-ms"]' 0

Moreover, nla get msecs() uses msecs to jiffies(), and u64 is silently cast to u32, so a larger value can bypass the min check:

e.g. 4294967296 == 0x100000000

--json '{"name": "arp cache", "parms": {"interval-probe-time-ms": 4294967296}}'

jq '.[] | select(.name == "arp cache" and has("config")) | .parms["interval-probe-time-ms"]' 0

msecs to jiffies() returns MAX JIFFY OFFSET if the value is larger than INT MAX. Also, INT MAX ms overflows int NEIGH VAR() when HZ > 1000 (Alpha, MIPS), and passing a negative integer to queue delayed work(unsigned long delay) causes sign extension, which wraps around the expiry time to the past, resulting in it being handled as 0 delay in the timer wheel.

Let's use NLA POLICY FULL RANGE() and limit the max to 1 day.

The same max check is applied to sysctl as well.

Note that this controls the probe interval for NTF MANAGED entries, so the max of 1 day is unlikely to break any deployments.