[lvc-project] [PATCH] sctp: fix null derefer in sctp_sf_do_5_1D_ce()

[Alexey Simakov]

The check of new_asoc->peer.adaptation_ind can fail,
leaving ai_ev unitilialized. In that case, the code
can jump to the nomem_authdev label and later call
sctp_ulpevent_free() with a null  ai_ev pointer.
Leading to potential null dereference.

Add check of ai_ev pointer before call of
sctp_ulpevent_free function.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 30f6ebf65bc4 ("sctp: add SCTP_AUTH_NO_AUTH type for AUTHENTICATION_EVENT")
Signed-off-by: Alexey Simakov <bigalex934 at gmail.com>
---
 net/sctp/sm_statefuns.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index a0524ba8d787..93cac73472c7 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -885,7 +885,8 @@ enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net,
 	return SCTP_DISPOSITION_CONSUME;
 
 nomem_authev:
-	sctp_ulpevent_free(ai_ev);
+	if (ai_ev)
+		sctp_ulpevent_free(ai_ev);
 nomem_aiev:
 	sctp_ulpevent_free(ev);
 nomem_ev:
-- 
2.34.1

I already have sent this patch from another email, but
he wasnt applicable since company mail server corrupt
it.