CVE-2023-52928 — bpf: Skip invalid kfunc call in backtrack_insn
In the Linux kernel, the following vulnerability has been resolved: bpf: Skip invalid kfunc call in backtrack_insn The verifier skips invalid kfunc call in check_kfunc_call(),…
Published: 2025-03-27 · CVSS: Unscored
In the Linux kernel, the following vulnerability has been resolved: bpf: Skip invalid kfunc call in backtrack_insn The verifier skips invalid kfunc call in check_kfunc_call(), which would be captured in fixup_kfunc_call() if such insn is not eliminated by dead code elimination. However, this can lead to the following warning in backtrack_insn(), also see [1]: ------------[ cut here ]------------ verifier backtracking bug WARNING: CPU: 6 PID: 8646 at kernel/bpf/verifier.c:2756 backtrack_insn kernel/bpf/verifier.c:2756 __mark_chain_precision kernel/bpf/verifier.c:3065 mark_chain_precision kernel/bpf/verifier.c:3165 adjust_reg_min_max_vals kernel/bpf/verifier.c:10715 check_alu_op kernel/bpf/verifier.c:10928 do_check kernel/bpf/verifier.c:13821 [inline] do_check_common kernel/bpf/verifier.c:16289 [...] So make backtracking conservative with this by returning ENOTSUPP. [1] https://lore.kernel.org/bpf/CACkBjsaXNceR8ZjkLG=dT3P=4A8SBsg0Z5h5PWLryF5=ghKq=g@mail.gmail.com/
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7