From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCHv2] net: bpf: reject invalid shifts Date: Wed, 13 Jan 2016 00:00:16 -0500 (EST) Message-ID: <20160113.000016.2304166666171388740.davem@davemloft.net> References: <1452651098.1223.41.camel@edumazet-glaptop2.roam.corp.google.com> <20160112.214315.2135966842775837844.davem@davemloft.net> <1452658064.1223.58.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: daniel@iogearbox.net, netdev@vger.kernel.org, ast@kernel.org, rabin@rab.in, alexei.starovoitov@gmail.com, linux-arm-kernel@lists.infradead.org To: eric.dumazet@gmail.com Return-path: In-Reply-To: <1452658064.1223.58.camel@edumazet-glaptop2.roam.corp.google.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org List-Id: netdev.vger.kernel.org From: Eric Dumazet Date: Tue, 12 Jan 2016 20:07:44 -0800 > On Tue, 2016-01-12 at 21:43 -0500, David Miller wrote: >> From: Eric Dumazet >> Date: Tue, 12 Jan 2016 18:11:38 -0800 >> >> > As I said, it is possible some guys never noticed their BPF program >> > were 'broken' because this invalid shift was hidden in a dead code >> > part. >> >> We should not hide bugs and unintended uses of operations with >> undefined behavior. > > JUMP 2: > SHR 45 > 2: RET 10 > > > was a valid program. > > But a dumb loader decided to know better. I guess you are uninterested in knowing your programs contains such garbage.