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 <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>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Annie Cherkaev 2017-07-15 15:08:58 -06:00 committed by Linus Torvalds
parent 4d3f5d04d6
commit 9f5af546e6
2 changed files with 3 additions and 3 deletions

View File

@ -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);

View File

@ -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)))