From ba1cffe0257bcd4d0070bc0e64f8ead97fefd148 Mon Sep 17 00:00:00 2001 From: Xi Wang Date: Tue, 27 Dec 2011 09:43:19 +0000 Subject: [PATCH] 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 Cc: Ralf Baechle Signed-off-by: David S. Miller --- net/ax25/af_ax25.c | 11 ++++++----- 1 file 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; } -- 2.30.2