Linux Kernel: Recursive Multicast Port Cleanup Stack Overflow
CVE-2026-99031 Published on October 23, 2026
net: bridge: avoid recursive multicast port cleanup
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.
Products Associated with CVE-2026-99031
stack.watch emails you whenever new vulnerabilities are published in Linux Kernel or Canonical Ubuntu Linux. Just hit a watch button to start following.
