diff options
| author | Xi Wang <xi.wang@gmail.com> | 2011-12-27 09:43:19 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-12-28 14:08:08 -0500 |
| commit | ba1cffe0257bcd4d0070bc0e64f8ead97fefd148 (patch) | |
| tree | 5584b7816f7eb46953611ec35628c6924ea5a2af /net/ax25 | |
| parent | fa84309533025eb3f03dc1d2d2be1c3ca206882a (diff) | |
| download | lwn-ba1cffe0257bcd4d0070bc0e64f8ead97fefd148.tar.gz lwn-ba1cffe0257bcd4d0070bc0e64f8ead97fefd148.zip | |
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>
Diffstat (limited to 'net/ax25')
| -rw-r--r-- | net/ax25/af_ax25.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c index b863c1877c80..3cd0a0dc91cb 100644 --- a/net/ax25/af_ax25.c +++ b/net/ax25/af_ax25.c @@ -545,15 +545,16 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname, ax25_cb *ax25; struct net_device *dev; char devname[IFNAMSIZ]; - int opt, res = 0; + unsigned long opt; + int res = 0; if (level != SOL_AX25) return -ENOPROTOOPT; - if (optlen < sizeof(int)) + if (optlen < sizeof(unsigned int)) return -EINVAL; - if (get_user(opt, (int __user *)optval)) + if (get_user(opt, (unsigned int __user *)optval)) return -EFAULT; lock_sock(sk); @@ -609,7 +610,7 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname, break; case AX25_IDLE: - if (opt < 0 || opt > ULONG_MAX / (60 * HZ)) { + if (opt > ULONG_MAX / (60 * HZ)) { res = -EINVAL; break; } @@ -617,7 +618,7 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname, break; case AX25_BACKOFF: - if (opt < 0 || opt > 2) { + if (opt > 2) { res = -EINVAL; break; } |