[PATCH 4.19 57/72] sctp: change to hold sk after auth shkey is created successfully

From: Greg Kroah-Hartman
Date: Tue Jul 02 2019 - 04:07:50 EST


From: Xin Long <lucien.xin@xxxxxxxxx>

[ Upstream commit 25bff6d5478b2a02368097015b7d8eb727c87e16 ]

Now in sctp_endpoint_init(), it holds the sk then creates auth
shkey. But when the creation fails, it doesn't release the sk,
which causes a sk defcnf leak,

Here to fix it by only holding the sk when auth shkey is created
successfully.

Fixes: a29a5bd4f5c3 ("[SCTP]: Implement SCTP-AUTH initializations.")
Reported-by: syzbot+afabda3890cc2f765041@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: syzbot+276ca1c77a19977c0130@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Acked-by: Neil Horman <nhorman@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sctp/endpointola.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/net/sctp/endpointola.c
+++ b/net/sctp/endpointola.c
@@ -126,10 +126,6 @@ static struct sctp_endpoint *sctp_endpoi
/* Initialize the bind addr area */
sctp_bind_addr_init(&ep->base.bind_addr, 0);

- /* Remember who we are attached to. */
- ep->base.sk = sk;
- sock_hold(ep->base.sk);
-
/* Create the lists of associations. */
INIT_LIST_HEAD(&ep->asocs);

@@ -167,6 +163,10 @@ static struct sctp_endpoint *sctp_endpoi
ep->prsctp_enable = net->sctp.prsctp_enable;
ep->reconf_enable = net->sctp.reconf_enable;

+ /* Remember who we are attached to. */
+ ep->base.sk = sk;
+ sock_hold(ep->base.sk);
+
return ep;

nomem_hmacs: