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Commit 39ebc027 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo Committed by David S. Miller
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[DCCP] getsockopt: Fix DCCP_SOCKOPT_[SEND,RECV]_CSCOV 



We were only checking if there was enough space to put the int, but
left len as specified by the (malicious) user, sigh, fix it by setting
len to sizeof(val) and transfering just one int worth of data, the one
asked for.

Also check for negative len values.

Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 53aadcc9

net/dccp/proto.c

+3 −1
Original line number Diff line number Diff line
@@ -575,7 +575,7 @@ static int do_dccp_getsockopt(struct sock *sk, int level, int optname, 
	if (get_user(len, optlen))

		return -EFAULT;



	if (len < sizeof(int))

	if (len < (int)sizeof(int))

		return -EINVAL;



	dp = dccp_sk(sk);
@@ -589,9 +589,11 @@ static int do_dccp_getsockopt(struct sock *sk, int level, int optname, 
					       (__be32 __user *)optval, optlen);

	case DCCP_SOCKOPT_SEND_CSCOV:

		val = dp->dccps_pcslen;

		len = sizeof(val);

		break;

	case DCCP_SOCKOPT_RECV_CSCOV:

		val = dp->dccps_pcrlen;

		len = sizeof(val);

		break;

	case 128 ... 191:

		return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,