linux-kernel - [PATCH 1/1] cifs: potential memory leaks when parsing mnt opts

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-next>] [day] [month] [year] [list]

Message-Id: <1426979310-31201-1-git-send-email-tsgatesv@gmail.com>
Date:	Sat, 21 Mar 2015 19:08:30 -0400
From:	Taesoo Kim <tsgatesv@...il.com>
To:	sfrench@...ba.org, linux-cifs@...r.kernel.org,
	samba-technical@...ts.samba.org, linux-kernel@...r.kernel.org
Cc:	taesoo@...ech.edu, changwoo@...ech.edu, sanidhya@...ech.edu,
	blee@...ech.edu, csong84@...ech.edu,
	Taesoo Kim <tsgatesv@...il.com>
Subject: [PATCH 1/1] cifs: potential memory leaks when parsing mnt opts

For example, when mount opt is redundently specified
(e.g., "user=A,user=B,user=C"), kernel kept allocating new key/val
with kstrdup() and overwrite previous ptr (to be freed).

Althouhg mkfs.cifs in userspace performs a bit of sanitization
(e.g., forcing one user option), current implementation is not
robust. Other options such as iocharset and domainanme are similary
vulnerable.

Signed-off-by: Taesoo Kim <tsgatesv@...il.com>
---
 fs/cifs/connect.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index d3aa999..4cb8450 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1599,6 +1599,8 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
 				pr_warn("CIFS: username too long\n");
 				goto cifs_parse_mount_err;
 			}
+
+			kfree(vol->username);
 			vol->username = kstrdup(string, GFP_KERNEL);
 			if (!vol->username)
 				goto cifs_parse_mount_err;
@@ -1700,6 +1702,7 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
 				goto cifs_parse_mount_err;
 			}
 
+			kfree(vol->domainname);
 			vol->domainname = kstrdup(string, GFP_KERNEL);
 			if (!vol->domainname) {
 				pr_warn("CIFS: no memory for domainname\n");
@@ -1731,6 +1734,7 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
 			}
 
 			 if (strncasecmp(string, "default", 7) != 0) {
+				kfree(vol->iocharset);
 				vol->iocharset = kstrdup(string,
 							 GFP_KERNEL);
 				if (!vol->iocharset) {
-- 
2.3.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/