4.4-stable review patch. If anyone has any objections, please let me know.
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From: Annie Cherkaev <annie.cherk@xxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Annie Cherkaev <annie.cherk@xxxxxxxxx>
Cc: Karsten Keil <isdn@xxxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/isdn/i4l/isdn_common.c | 1 +
drivers/isdn/i4l/isdn_net.c | 5 ++---
2 files changed, 3 insertions(+), 3 deletions(-)
--- 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,
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);
--- 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)))