CVE-2026-99031

About vulnerability

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

net: bridge: avoid recursive multicast port cleanup

br_multicast_sg_del_exclude_ports() removes automatically added STAR_EXCL port groups by calling br_multicast_del_pg(). For S,G entries, that deletion calls back into br_multicast_sg_del_exclude_ports(), so a large number of STAR_EXCL ports consumes one kernel stack frame per port and can hit the stack guard page.

Keep the complete port-group deletion path for cleanup, but suppress the S,G exclude-port cleanup while that helper is already walking the same entry. Normal deletion callers retain the existing behavior.

Affected product:

AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , Debian 11 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU

Affected packages:

kernel @ 5.14.0 (+4 more)