linux-kernel - [PATCH RFC v2 4/4] mm/mempolicy: add nodes_empty check in SYSC_migrate

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1509099265-30868-5-git-send-email-xieyisheng1@huawei.com>
Date:   Fri, 27 Oct 2017 18:14:25 +0800
From:   Yisheng Xie <xieyisheng1@...wei.com>
To:     <akpm@...ux-foundation.org>, <vbabka@...e.cz>, <mhocko@...e.com>,
        <mingo@...nel.org>, <rientjes@...gle.com>,
        <n-horiguchi@...jp.nec.com>, <salls@...ucsb.edu>
CC:     <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
        <tanxiaojun@...wei.com>, <linux-api@...r.kernel.org>
Subject: [PATCH RFC v2 4/4] mm/mempolicy: add nodes_empty check in SYSC_migrate_pages

As manpage of migrate_pages, the errno should be set to EINVAL when none
of the specified nodes contain memory. However, when new_nodes is null,
i.e. the specified nodes also do not have memory, as the following case:

	new_nodes = 0;
	old_nodes = 0xf;
	ret = migrate_pages(pid, old_nodes, new_nodes, MAX);

The ret will be 0 and no errno is set.

This patch is to add nodes_empty check to fix above case.

Signed-off-by: Yisheng Xie <xieyisheng1@...wei.com>
---
 mm/mempolicy.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 8798ecb..58352cc 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1402,6 +1402,11 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
 	if (err)
 		goto out;
 
+	if (nodes_empty(*new)) {
+		err = -EINVAL;
+		goto out;
+	}
+
 	/* Find the mm_struct */
 	rcu_read_lock();
 	task = pid ? find_task_by_vpid(pid) : current;
-- 
1.7.12.4