From 9f5af546e6acc30f075828cb58c7f09665033967 Mon Sep 17 00:00:00 2001 From: Annie Cherkaev Date: Sat, 15 Jul 2017 15:08:58 -0600 Subject: isdn/i4l: fix buffer overflow 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 Signed-off-by: Annie Cherkaev Cc: Karsten Keil Cc: Kees Cook Cc: stable@kernel.org Signed-off-by: Linus Torvalds --- drivers/isdn/i4l/isdn_common.c | 1 + drivers/isdn/i4l/isdn_net.c | 5 ++--- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/isdn/i4l/isdn_common.c b/drivers/isdn/i4l/isdn_common.c index 89b09c51ab7c..38a5bb764c7b 100644 --- a/drivers/isdn/i4l/isdn_common.c +++ b/drivers/isdn/i4l/isdn_common.c @@ -1376,6 +1376,7 @@ 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))) -- cgit