[PATCH 4.14 06/21] sctp: not allow to set asoc prsctp_enable by sockopt

Greg Kroah-Hartman
2018-11-21T19:09:34Z

From: Xin Long <lucien.xin@gmail.com>

[ Upstream commit cc3ccf26f0649089b3a34a2781977755ea36e72c ]

As rfc7496#section4.5 says about SCTP_PR_SUPPORTED:

This socket option allows the enabling or disabling of the
negotiation of PR-SCTP support for future associations. For existing
associations, it allows one to query whether or not PR-SCTP support
was negotiated on a particular association.

It means only sctp sock's prsctp_enable can be set.

Note that for the limitation of SCTP_{CURRENT|ALL}_ASSOC, we will
add it when introducing SCTP_{FUTURE|CURRENT|ALL}_ASSOC for linux
sctp in another patchset.

v1->v2:
- drop the params.assoc_id check as Neil suggested.

Fixes: 28aa4c26fce2 ("sctp: add SCTP_PR_SUPPORTED on sctp sockopt")
Reported-by: Ying Xu <yinxu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/sctp/socket.c | 26 +++++---------------------
1 file changed, 5 insertions(+), 21 deletions(-)

--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3750,32 +3750,16 @@ static int sctp_setsockopt_pr_supported(
unsigned int optlen)
{
struct sctp_assoc_value params;
- struct sctp_association *asoc;
- int retval = -EINVAL;

if (optlen != sizeof(params))
- goto out;
+ return -EINVAL;

- if (copy_from_user(&params, optval, optlen)) {
- retval = -EFAULT;
- goto out;
- }
+ if (copy_from_user(&params, optval, optlen))
+ return -EFAULT;

- asoc = sctp_id2assoc(sk, params.assoc_id);
- if (asoc) {
- asoc->prsctp_enable = !!params.assoc_value;
- } else if (!params.assoc_id) {
- struct sctp_sock *sp = sctp_sk(sk);
+ sctp_sk(sk)->ep->prsctp_enable = !!params.assoc_value;

- sp->ep->prsctp_enable = !!params.assoc_value;
- } else {
- goto out;
- }
-
- retval = 0;
-
-out:
- return retval;
+ return 0;
}

static int sctp_setsockopt_default_prinfo(struct sock *sk,