From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933743AbaH0MQS (ORCPT ); Wed, 27 Aug 2014 08:16:18 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:7807 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933368AbaH0MQP (ORCPT ); Wed, 27 Aug 2014 08:16:15 -0400 Message-ID: <53FDCBF1.2020606@huawei.com> Date: Wed, 27 Aug 2014 20:15:45 +0800 From: Wang Nan User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: Masami Hiramatsu CC: Ingo Molnar , Thomas Gleixner , "Andi Kleen" , Pei Feiyue , , Subject: Re: [PATCH] kprobes/x86: opt: free optinsn cache when range check fails References: <1406550019-70935-1-git-send-email-wangnan0@huawei.com> <53D6FC38.8070801@hitachi.com> In-Reply-To: <53D6FC38.8070801@hitachi.com> Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.111.69.90] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014/7/29 9:43, Masami Hiramatsu wrote: > (2014/07/28 21:20), Wang Nan wrote: >> This patch frees optinsn slot when range check error to prevent memory >> leaks. Before this patch, cache entry in kprobe_insn_cache won't be >> freed if kprobe optimizing fails due to range check failure. >> >> Signed-off-by: Wang Nan > > Oops, thank you for finding it! > > Acked-by: Masami Hiramatsu > Hi Masami Hiramatsu, I don't find this patch in newest upstream. Is there any problem? > BTW, would you really have hit this error? > I'd like to know the case if this really happens. > >> --- >> arch/x86/kernel/kprobes/opt.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c >> index f304773..f1314d0 100644 >> --- a/arch/x86/kernel/kprobes/opt.c >> +++ b/arch/x86/kernel/kprobes/opt.c >> @@ -338,8 +338,10 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op) >> * a relative jump. >> */ >> rel = (long)op->optinsn.insn - (long)op->kp.addr + RELATIVEJUMP_SIZE; >> - if (abs(rel) > 0x7fffffff) >> + if (abs(rel) > 0x7fffffff) { >> + __arch_remove_optimized_kprobe(op, 0); >> return -ERANGE; >> + } >> >> buf = (u8 *)op->optinsn.insn; >> >> > >