git: bd0ad8209d55 - stable/13 - altq: Fix panics on rmc_restart()

[Kristof Provost]

The branch stable/13 has been updated by kp:

URL: https://cgit.FreeBSD.org/src/commit/?id=bd0ad8209d55aca19b5f69b2ddc7c956863382b3

commit bd0ad8209d55aca19b5f69b2ddc7c956863382b3
Author:     Kristof Provost <kp at FreeBSD.org>
AuthorDate: 2021-08-21 11:42:27 +0000
Commit:     Kristof Provost <kp at FreeBSD.org>
CommitDate: 2021-08-30 08:02:14 +0000

    altq: Fix panics on rmc_restart()
    
    rmc_restart() is called from a timer, but can trigger traffic. This
    means the curvnet context will not be set.
    Use the vnet associated with the interface we're currently processing to
    set it. We also have to enter net_epoch here, for the same reason.
    
    Reviewed by:    mjg
    MFC after:      1 week
    Sponsored by:   Rubicon Communications, LLC ("Netgate")
    Differential Revision:  https://reviews.freebsd.org/D31642
    
    (cherry picked from commit 159258afb50ad57f7ed27fe86ded83a7b3a26f90)
---
 sys/net/altq/altq_rmclass.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sys/net/altq/altq_rmclass.c b/sys/net/altq/altq_rmclass.c
index a6ede6feebe2..a9af314cd48a 100644
--- a/sys/net/altq/altq_rmclass.c
+++ b/sys/net/altq/altq_rmclass.c
@@ -1554,10 +1554,13 @@ rmc_restart(void *arg)
 {
 	struct rm_class *cl = arg;
 	struct rm_ifdat	*ifd = cl->ifdat_;
+	struct epoch_tracker et;
 	int		 s;
 
 	s = splnet();
+	NET_EPOCH_ENTER(et);
 	IFQ_LOCK(ifd->ifq_);
+	CURVNET_SET(ifd->ifq_->altq_ifp->if_vnet);
 	if (cl->sleeping_) {
 		cl->sleeping_ = 0;
 		cl->undertime_.tv_sec = 0;
@@ -1567,7 +1570,9 @@ rmc_restart(void *arg)
 			(ifd->restart)(ifd->ifq_);
 		}
 	}
+	CURVNET_RESTORE();
 	IFQ_UNLOCK(ifd->ifq_);
+	NET_EPOCH_EXIT(et);
 	splx(s);
 }