linux-kernel - [PATCH] mm/mempolicy: fix get

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>] [day] [month] [year] [list]

Message-Id: <20220601093211.2970565-1-tianyu.li@arm.com>
Date:   Wed,  1 Jun 2022 17:32:11 +0800
From:   Tianyu Li <tianyu.li@....com>
To:     Andrew Morton <akpm@...ux-foundation.org>,
        Arnd Bergmann <arnd@...db.de>,
        linux-mm@...ck.org (open list:MEMORY MANAGEMENT),
        linux-kernel@...r.kernel.org (open list)
Cc:     nd@....com, Tianyu Li <tianyu.li@....com>
Subject: [PATCH] mm/mempolicy: fix get_nodes out of bound access

When user specified more nodes than supported,
get_nodes will access nmask array out of bound.

Fixes: e130242dc351 ("mm: simplify compat numa syscalls")
Signed-off-by: Tianyu Li <tianyu.li@....com>
---
 mm/mempolicy.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 0b4ba3ee810e..9f27dc4b66ba 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1388,7 +1388,7 @@ static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
 		unsigned long bits = min_t(unsigned long, maxnode, BITS_PER_LONG);
 		unsigned long t;
 
-		if (get_bitmap(&t, &nmask[maxnode / BITS_PER_LONG], bits))
+		if (get_bitmap(&t, &nmask[(maxnode - 1) / BITS_PER_LONG], bits))
 			return -EFAULT;
 
 		if (maxnode - bits >= MAX_NUMNODES) {
-- 
2.25.1