From: Annie Cherkaev <annie.cherk@gmail.com>
Date: Sat, 15 Jul 2017 15:08:58 -0600
Subject: [PATCH] isdn/i4l: fix buffer overflow
References: bnc#1060662
Patch-mainline: v4.12.5
Git-commit: 9f5af546e6acc30f075828cb58c7f09665033967
commit 9f5af546e6acc30f075828cb58c7f09665033967 upstream.
This fixes a potential buffer overflow in isdn_net.c caused by an
unbounded strcpy.
[ ISDN seems to be effectively unmaintained, and the I4L driver in
particular is long deprecated, but in case somebody uses this..
- Linus ]
Signed-off-by: Jiten Thakkar <jitenmt@gmail.com>
Signed-off-by: Annie Cherkaev <annie.cherk@gmail.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/isdn/i4l/isdn_common.c | 1 +
drivers/isdn/i4l/isdn_net.c | 5 ++---
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/isdn/i4l/isdn_common.c b/drivers/isdn/i4l/isdn_common.c
index 9b856e1890d1..e4c43a17b333 100644
--- a/drivers/isdn/i4l/isdn_common.c
+++ b/drivers/isdn/i4l/isdn_common.c
@@ -1379,6 +1379,7 @@ isdn_ioctl(struct file *file, uint cmd, ulong arg)
if (arg) {
if (copy_from_user(bname, argp, sizeof(bname) - 1))
return -EFAULT;
+ bname[sizeof(bname)-1] = 0;
} else
return -EINVAL;
ret = mutex_lock_interruptible(&dev->mtx);
diff --git a/drivers/isdn/i4l/isdn_net.c b/drivers/isdn/i4l/isdn_net.c
index c151c6daa67e..f63a110b7bcb 100644
--- a/drivers/isdn/i4l/isdn_net.c
+++ b/drivers/isdn/i4l/isdn_net.c
@@ -2611,10 +2611,9 @@ isdn_net_newslave(char *parm)
char newname[10];
if (p) {
- /* Slave-Name MUST not be empty */
- if (!strlen(p + 1))
+ /* Slave-Name MUST not be empty or overflow 'newname' */
+ if (strscpy(newname, p + 1, sizeof(newname)) <= 0)
return NULL;
- strcpy(newname, p + 1);
*p = 0;
/* Master must already exist */
if (!(n = isdn_net_findif(parm)))
--
2.14.2