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

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-25 · updated 2026-10-19

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 products

Linux kernel: 6.15 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.3. Check the vendor advisory for mitigations.

References

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