ax25: avoid overflows in ax25_setsockopt()
authorXi Wang <xi.wang@gmail.com>
Tue, 27 Dec 2011 09:43:19 +0000 (09:43 +0000)
committerDavid S. Miller <davem@davemloft.net>
Wed, 28 Dec 2011 19:08:08 +0000 (14:08 -0500)
commitba1cffe0257bcd4d0070bc0e64f8ead97fefd148
tree5584b7816f7eb46953611ec35628c6924ea5a2af
parentfa84309533025eb3f03dc1d2d2be1c3ca206882a
ax25: avoid overflows in ax25_setsockopt()

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 <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ax25/af_ax25.c