CVE-2026-74344
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk3th percentile - higher than 3% of all known CVEs
Summary
In the Linux kernel BPF mechanism, when freeing bpf_rb_root, the red-black tree node pointers are not cleared. If the object survives the free, it may contain stale pointers to the freed structure, which upon address reuse can lead to incorrect tree removal.
Risk Assessment
This can lead to memory corruption, incorrect BPF program behavior, or potential privilege escalation in BPF environments.
Recommendation
Apply the Linux kernel patch that clears rb nodes and releases the owner before dropping the object.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: bpf: Clear rb node linkage when freeing bpf_rb_root bpf_rb_root_free() detaches the root by copying the current rb_root_cached and then replacing the live root with RB_ROOT_CACHED. It then walks the copied root and drops each object contained in the tree. This leaves the rb node state intact while dropping the object. If the object is refcounted and survives the drop, its bpf_rb_node_kern still contains an owner pointer to the freed root and stale rb tree linkage. If a later bpf_rb_root allocation reuses the same address, bpf_rbtree_remove() can incorrectly pass the owner check and call rb_erase_cached() on a node whose rb pointers belong to the old tree. Mirror the list draining behavior by marking nodes as busy while the root is being detached, then clear the rb node and release the owner before dropping the containing object. This makes surviving nodes unowned and safe to reject from remove or accept for a later add.