On Wed, Jan 06, 2016 at 09:31:27PM +0100, Rabin Vincent wrote: > On Tue, Jan 05, 2016 at 09:55:58AM -0800, Alexei Starovoitov wrote: > > this one is better to be addressed in verifier instead of eBPF JITs. > > Please reject it in check_alu_op() instead. > > AFAICS the eBPF verifier is not called on the eBPF filters generated by > the BPF->eBPF conversion in net/core/filter.c, so performing this check > only in check_alu_op() will be insufficient. So I think we'd need to > add this check to bpf_check_classic() too. Or am I missing something?
correct. the check is needed in bpf_check_classic() too and I believe it's ok to tighten it up in this case, since >32 shift is invalid/undefined anyway. We can either accept it as nop or K&=31 or error. I think returning error is more user friendly long term, though there is a small risk of rejecting previously loadable broken programs. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
