From: mvs <mvs@openbsd.org>
Date: Thu, 1 Apr 2021 08:39:52 +0000 (+0000)
Subject: Push kernel lock down to umb_rtrequest().
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=99ae0d529b6d032ce4069677ab2067bf7b453da4;p=openbsd

Push kernel lock down to umb_rtrequest().

We are going to unlock PF_ROUTE sockets. This means `if_rtrequest'
handler will be performed without kernel lock.

umb_rtrequest() calls umb_send_inet_proposal() which touches kernel lock
protected `ipv{4,6}dns' array. Also umb_rtrequest() is the only handler
which requires kernel lock to be held. So push the lock down to
umb_rtrequest() instead of grab it around `if_rtrequest' call.

This hunk was commited separately for decreases PF_ROUTE sockets
unlocking diff.

ok gerhard@ deraadt@
---

diff --git a/sys/dev/usb/if_umb.c b/sys/dev/usb/if_umb.c
index 655a7f5829e..eba04afddfc 100644
--- a/sys/dev/usb/if_umb.c
+++ b/sys/dev/usb/if_umb.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_umb.c,v 1.42 2021/03/30 20:58:19 sthen Exp $ */
+/*	$OpenBSD: if_umb.c,v 1.43 2021/04/01 08:39:52 mvs Exp $ */
 
 /*
  * Copyright (c) 2016 genua mbH
@@ -1053,10 +1053,12 @@ umb_rtrequest(struct ifnet *ifp, int req, struct rtentry *rt)
 	struct umb_softc *sc = ifp->if_softc;
 
 	if (req == RTM_PROPOSAL) {
+		KERNEL_LOCK();
 		umb_send_inet_proposal(sc, AF_INET);
 #ifdef INET6
 		umb_send_inet_proposal(sc, AF_INET6);
 #endif
+		KERNEL_UNLOCK();
 		return;
 	}