staging/cxt1e1/linux.c: Correct arbitrary memory write in c4_ioctl()

The function c4_ioctl() writes data from user in ifr->ifr_data
to the kernel struct data arg, without any iolen bounds checking.
This can lead to a arbitrary write outside of the struct data arg.
Corrected by adding bounds-checking of iolen before the copy_from_user().

Signed-off-by: Salva Peiró <speiro@ai2.upv.es>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Salva Peiró 2014-03-03 08:44:04 +01:00 committed by Greg Kroah-Hartman
parent 0414855fdc
commit 084b6e7765

View File

@ -866,6 +866,8 @@ c4_ioctl (struct net_device *ndev, struct ifreq *ifr, int cmd)
_IOC_SIZE (iocmd));
#endif
iolen = _IOC_SIZE (iocmd);
if (iolen > sizeof(arg))
return -EFAULT;
data = ifr->ifr_data + sizeof (iocmd);
if (copy_from_user (&arg, data, iolen))
return -EFAULT;