CVE-2025-68325

In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_cake: Fix incorrect qlen reduction in cake_drop In cake_drop(), qdisc_tree_reduce_backlog() is used to update the qlen and backlog of the qdisc hierarchy. Its caller, cake_enqueue(), assumes that the parent qdisc will enqueue the current packet. However, this assumption breaks when cake_enqueue() returns NET_XMIT_CN: the parent qdisc stops enqueuing current packet, leaving the tree qlen/backlog accounting inconsistent. This mismatch can lead to a NULL dereference (e.g., when the parent Qdisc is qfq_qdisc). This patch computes the qlen/backlog delta in a more robust way by observing the difference before and after the series of cake_drop() calls, and then compensates the qdisc tree accounting if cake_enqueue() returns NET_XMIT_CN. To ensure correct compensation when ACK thinning is enabled, a new variable is introduced to keep qlen unchanged.

The following products are affected by CVE-2025-68325 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2025-68325.

URL	Resource
https://git.kernel.org/stable/c/0b6216f9b3d1c33c76f74511026e5de5385ee520
https://git.kernel.org/stable/c/3ed6c458530a547ed0c9ea0b02b19bab620be88b
https://git.kernel.org/stable/c/529c284cc2815c8350860e9a31722050fe7117cb
https://git.kernel.org/stable/c/9fefc78f7f02d71810776fdeb119a05a946a27cc