Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Check ancestor frames for rbtree callbacks bpf_rbtree_add() invokes its comparator while the caller holds the root lock. The native insertion code retains raw parent and link pointers across the callback, so the verifier prohibits unlocking, consuming tree nodes, or changing RCU state from that callback. in_rbtree_lock_required_cb() only checks the innermost verifier frame. Static subprogram calls are permitted while holding a spin lock, and such a call pushes a frame without in_callback_fn set. Consequently, all callback restrictions disappear in the nested frame. The subprogram can unlock the tree, remove and drop the node being compared, then relock. Native insertion resumes with the stale parent pointer and links freed memory into the tree. Walk all active frames for the rbtree callback instead. Benign static subprograms remain permitted, while callback restrictions follow execution into nested frames.
References
- https://git.kernel.org/stable/c/2410cb2ac0416dd2795a81984c8c73d7250bd8c4
- https://git.kernel.org/stable/c/369f4ce734570bdfedaa4b5ca50e2a3f6a892728
- https://git.kernel.org/stable/c/b545fa447e09e6844868deb2bee228827fe54d15
FAQ
What is CVE-2026-98047?
CVE-2026-98047 is a documented vulnerability. In the Linux kernel, the following vulnerability has been resolved: bpf: Check ancestor frames for rbtree callbacks bpf_rbtree_add() invokes its comparator while the caller holds the root lock. The ...
How severe is CVE-2026-98047?
CVSS scoring is not yet available for CVE-2026-98047. Check NVD for updates.
Is there a patch for CVE-2026-98047?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.