Re: [PATCH -next] ax25: avoid overflows in ax25_setsockopt()
From: David Miller <davem@davemloft.net>
Date: 2011-12-28 19:08:19
Also in:
linux-hams
From: Xi Wang <xi.wang@gmail.com> Date: Tue, 27 Dec 2011 14:43:19 -0500
Commit be639ac6 ("NET: AX.25: Check ioctl arguments to avoid overflows
further down the road") rejects very large arguments, but doesn't
completely fix overflows on 64-bit systems. Consider the AX25_T2 case.
int opt;
...
if (opt < 1 || opt > ULONG_MAX / HZ) {
res = -EINVAL;
break;
}
ax25->t2 = opt * HZ;
The 32-bit multiplication opt * HZ would overflow before being assigned
to 64-bit ax25->t2. This patch changes "opt" to unsigned long.
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Cc: Ralf Baechle <redacted>Applied.