ax25: avoid overflows in ax25_setsockopt() (ba1cffe0) · Commits · 戴 / test

Commit ("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

+6 −5

Original line number	Diff line number	Diff line
		@@ -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;
		}

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