CVE-2026-63969

Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix possible infinite loop in rt6_fill_node() Sashiko reported this issue [1]. Apply the same fix as commit f8d8ce1b515a ("ipv6: fix possible infinite loop in fib6_info_uses_dev()"). Writers holding tb6_lock can list_del_rcu(&rt->fib6_siblings) without waiting for RCU readers; rt->fib6_siblings.next then still points into the old ring and this softirq-side walker never reaches &rt->fib6_siblings, causing a CPU stall. fib6_del_route() always WRITE_ONCE()s rt->fib6_nsiblings to 0 before list_del_rcu(), so an inside-loop check is a reliable detach signal. [1] https://sashiko.dev/#/patchset/20260526020227.4857-1-jiayuan.chen%40linux.dev

References

• https://git.kernel.org/stable/c/279853aec9f58d5cd723e6e5617c1c3337b30383
• https://git.kernel.org/stable/c/5e40de719ee76b8d96e2556ce36dbd3bd07bf37d
• https://git.kernel.org/stable/c/9f72412bcf60144f252b0d6205106abf14344abc
• https://git.kernel.org/stable/c/b014a63d2f2c2c767762b548381882dfb1655529
• https://git.kernel.org/stable/c/c65b1f60237daac7c56c2652e064cc566a45dc81