From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752300AbeCCULW (ORCPT ); Sat, 3 Mar 2018 15:11:22 -0500 Received: from mail-wr0-f193.google.com ([209.85.128.193]:33868 "EHLO mail-wr0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752129AbeCCULU (ORCPT ); Sat, 3 Mar 2018 15:11:20 -0500 X-Google-Smtp-Source: AG47ELvMRsPncBmgZnufvfxAa+ITUqevghaYxcUkspjZbsPifI5xJJzIql6GyyQ3zx+NYKOTNbQRVg== Date: Sat, 3 Mar 2018 23:11:16 +0300 From: Alexey Dobriyan To: akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, yeohc@au1.ibm.com, jann@thejh.net Subject: [PATCH] mm: relax ptrace mode in process_vm_readv(2) Message-ID: <20180303201116.GA10031@avx2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.7.2 (2016-11-26) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is more natural to check for read-from-memory permissions in case of process_vm_readv() as PTRACE_MODE_ATTACH is equivalent to write permissions. Signed-off-by: Alexey Dobriyan --- mm/process_vm_access.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -204,7 +204,7 @@ static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter, goto free_proc_pages; } - mm = mm_access(task, PTRACE_MODE_ATTACH_REALCREDS); + mm = mm_access(task, vm_write ? PTRACE_MODE_ATTACH_REALCREDS : PTRACE_MODE_READ_REALCREDS); if (!mm || IS_ERR(mm)) { rc = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH; /*