[DCCP] getsockopt: Fix DCCP_SOCKOPT_[SEND,RECV]_CSCOV (39ebc027) · Commits · 戴 / test

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:

Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by:

David S. Miller <davem@davemloft.net>

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,

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