CVE-2026-98060bpf: Reject resilient lock operations in rbtree callbacks

Official description

In the Linux kernel, the following vulnerability has been resolved: bpf: Reject resilient lock operations in rbtree callbacks __bpf_rbtree_add() keeps parent and link pointers live across calls to the program-supplied comparison callback. The verifier therefore requires the root's lock to remain held throughout the callback. The helper path enforces this rule for bpf_spin_lock() and bpf_spin_unlock(), but the resilient lock kfunc argument path does not. Since resilient locks may protect BPF rbtree roots, a callback can release the root lock and let another CPU remove and free the node referenced by the in-progress tree walk. The walk then resumes using freed pointers. Reject resilient lock kfuncs in an rbtree comparison callback, matching the existing policy for the spin lock helpers. Resilient-lock-protected trees remain valid when their comparison callbacks leave lock state alone.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/cc2e065ed206aecd9b94564779244f3ffb26e356
• https://git.kernel.org/stable/c/71930202a0a0c49f0a3b45b41907a074cb780266
• https://git.kernel.org/stable/c/7b7b8b5960102566bd625ae829d1f330c5b5d104