From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 11 Jan 2012 07:46:27 +0000 (+0300)
Subject: cifs: integer overflow in parse_dacl()
X-Git-Tag: archive/raspbian/4.9.13-1+rpi1~10^2~11968^2~4^2
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks:///%22http:/www.example.com/cgi/%22https:/%22bookmarks:/?a=commitdiff_plain;h=7250170c9ed00f3b74b11b98afefab45020672dd;p=linux-4.9.git

cifs: integer overflow in parse_dacl()

On 32 bit systems num_aces * sizeof(struct cifs_ace *) could overflow
leading to a smaller ppace buffer than we expected.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
---

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index 72ddf23ef6f7..c1b254487388 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -909,6 +909,8 @@ static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
 		umode_t group_mask = S_IRWXG;
 		umode_t other_mask = S_IRWXU | S_IRWXG | S_IRWXO;
 
+		if (num_aces > ULONG_MAX / sizeof(struct cifs_ace *))
+			return;
 		ppace = kmalloc(num_aces * sizeof(struct cifs_ace *),
 				GFP_KERNEL);
 		if (!ppace) {