5.4-stable patches

added patches:
	net-sched-sch_taprio-reset-child-qdiscs-before-freeing-them.patch

diff --git a/queue-5.4/net-sched-sch_taprio-reset-child-qdiscs-before-freeing-them.patch b/queue-5.4/net-sched-sch_taprio-reset-child-qdiscs-before-freeing-them.patch
new file mode 100644 (file)
index 0000000..84649b0
--- /dev/null
+++ b/queue-5.4/net-sched-sch_taprio-reset-child-qdiscs-before-freeing-them.patch
@@ -0,0 +1,65 @@
+From foo@baz Wed Dec 30 04:10:55 PM CET 2020
+From: Davide Caratti <dcaratti@redhat.com>
+Date: Wed, 16 Dec 2020 19:33:29 +0100
+Subject: net/sched: sch_taprio: reset child qdiscs before freeing them
+
+From: Davide Caratti <dcaratti@redhat.com>
+
+[ Upstream commit 44d4775ca51805b376a8db5b34f650434a08e556 ]
+
+syzkaller shows that packets can still be dequeued while taprio_destroy()
+is running. Let sch_taprio use the reset() function to cancel the advance
+timer and drop all skbs from the child qdiscs.
+
+Fixes: 5a781ccbd19e ("tc: Add support for configuring the taprio scheduler")
+Link: https://syzkaller.appspot.com/bug?id=f362872379bf8f0017fb667c1ab158f2d1e764ae
+Reported-by: syzbot+8971da381fb5a31f542d@syzkaller.appspotmail.com
+Signed-off-by: Davide Caratti <dcaratti@redhat.com>
+Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
+Link: https://lore.kernel.org/r/63b6d79b0e830ebb0283e020db4df3cdfdfb2b94.1608142843.git.dcaratti@redhat.com
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ net/sched/sch_taprio.c |   17 ++++++++++++++++-
+ 1 file changed, 16 insertions(+), 1 deletion(-)
+
+--- a/net/sched/sch_taprio.c
++++ b/net/sched/sch_taprio.c
+@@ -1597,6 +1597,21 @@ free_sched:
+       return err;
+ }
+ 
++static void taprio_reset(struct Qdisc *sch)
++{
++      struct taprio_sched *q = qdisc_priv(sch);
++      struct net_device *dev = qdisc_dev(sch);
++      int i;
++
++      hrtimer_cancel(&q->advance_timer);
++      if (q->qdiscs) {
++              for (i = 0; i < dev->num_tx_queues && q->qdiscs[i]; i++)
++                      qdisc_reset(q->qdiscs[i]);
++      }
++      sch->qstats.backlog = 0;
++      sch->q.qlen = 0;
++}
++
+ static void taprio_destroy(struct Qdisc *sch)
+ {
+       struct taprio_sched *q = qdisc_priv(sch);
+@@ -1607,7 +1622,6 @@ static void taprio_destroy(struct Qdisc
+       list_del(&q->taprio_list);
+       spin_unlock(&taprio_list_lock);
+ 
+-      hrtimer_cancel(&q->advance_timer);
+ 
+       taprio_disable_offload(dev, q, NULL);
+ 
+@@ -1954,6 +1968,7 @@ static struct Qdisc_ops taprio_qdisc_ops
+       .init           = taprio_init,
+       .change         = taprio_change,
+       .destroy        = taprio_destroy,
++      .reset          = taprio_reset,
+       .peek           = taprio_peek,
+       .dequeue        = taprio_dequeue,
+       .enqueue        = taprio_enqueue,

diff --git a/queue-5.4/series b/queue-5.4/series
new file mode 100644 (file)
index 0000000..d37879e
--- /dev/null
+++ b/queue-5.4/series
@@ -0,0 +1 @@
+net-sched-sch_taprio-reset-child-qdiscs-before-freeing-them.patch