CVE-2026-23437

Summary

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

net: shaper: protect late read accesses to the hierarchy

We look up a netdev during prep of Netlink ops (pre- callbacks) and take a ref to it. Then later in the body of the callback we take its lock or RCU which are the actual protections.

This is not proper, a conversion from a ref to a locked netdev must include a liveness check (a check if the netdev hasn't been unregistered already). Fix the read cases (those under RCU). Writes needs a separate change to protect from creating the hierarchy after flush has already run.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux4b623f9f0f59652ea71fcb27d60b4c3b65126dbb < 581eee0890a8bde44f1fb78ad3e70502a897d583affected
LinuxLinux4b623f9f0f59652ea71fcb27d60b4c3b65126dbb < 348758ba74e6a348299965b16a97cfb817545cc0affected
LinuxLinux4b623f9f0f59652ea71fcb27d60b4c3b65126dbb < 0f9ea7141f365b4f27226898e62220fb98ef8dc6affected
LinuxLinux6.13affected
LinuxLinux0 < 6.13unaffected
LinuxLinux6.18.20 <= 6.18.*unaffected
LinuxLinux6.19.10 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References