Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757521Ab1DXMBY (ORCPT ); Sun, 24 Apr 2011 08:01:24 -0400 Received: from mail-pv0-f174.google.com ([74.125.83.174]:46792 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756605Ab1DXMBX (ORCPT ); Sun, 24 Apr 2011 08:01:23 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=lzZritXQV8+fbN61V6ei7SDC2YvjgS+rt7pMK/Lr4+IVEFukfH02/WDgig4bj3+BHJ UFSbJ6tr6+/f0bmIeKGKR0O/guo+dPPKcHoMxlG63EyY8nu8lgT5SyIZhudNaNExetsJ UPzVT9pYC/xWyvREcDPvGn2JOcgrV/Tn3YfC8= From: bookjovi@gmail.com To: bookjovi@gmail.com Cc: Andrew Morton (commit_signer:19/51=37%), Al Viro (commit_signer:17/51=33%), David Rientjes (commit_signer:7/51=14%), KOSAKI Motohiro (commit_signer:5/51=10%), Stephen Wilson (commit_signer:4/51=8%), linux-kernel@vger.kernel.org (open list) Subject: [PATCH] proc: put check_mem_permission before __get_free_page in mem_read Date: Sun, 17 Apr 2011 20:20:01 -0400 Message-Id: <1303086002-6961-1-git-send-email-bookjovi@gmail.com> X-Mailer: git-send-email 1.7.2.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1577 Lines: 69 From: Jovi Zhang It should be better if put check_mem_permission before __get_free_page in mem_read, to be same as function mem_write. Signed-off-by: Jovi Zhang --- fs/proc/base.c | 24 ++++++++++-------------- 1 files changed, 10 insertions(+), 14 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index dfa5327..d66126d 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -831,23 +831,21 @@ static ssize_t mem_read(struct file * file, char __user * buf, if (!task) goto out_no_task; - ret = -ENOMEM; - page = (char *)__get_free_page(GFP_TEMPORARY); - if (!page) - goto out; - mm = check_mem_permission(task); ret = PTR_ERR(mm); if (IS_ERR(mm)) - goto out_free; + goto out_task; ret = -EIO; - if (file->private_data != (void*)((long)current->self_exec_id)) - goto out_put; + goto out_mm; + + ret = -ENOMEM; + page = (char *)__get_free_page(GFP_TEMPORARY); + if (!page) + goto out_mm; ret = 0; - while (count > 0) { int this_len, retval; @@ -870,12 +868,10 @@ static ssize_t mem_read(struct file * file, char __user * buf, count -= retval; } *ppos = src; - -out_put: - mmput(mm); -out_free: free_page((unsigned long) page); -out: +out_mm: + mmput(mm); +out_task: put_task_struct(task); out_no_task: return ret; -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/