CVE-2026-98084 bpf: backtracking shouldn't clear outer frame R1-R5 for callbacks

In the Linux kernel, the following vulnerability has been resolved: bpf: backtracking shouldn't clear outer frame R1-R5 for callbacks When processing calls to bpfloop verifier marks R1 and R4 as precise. R1 tracks loop iterations number and because of the 'callbackdepth R1' mechanics in...

CVE-2026-98084

The Linux kernel contains a vulnerability in the BPF verifier related to bpf_loop(). When processing callbacks, the verifier is intended to mark register R1 (which tracks loop iterations) as precise to satisfy callback_depth