Merge tag 'v5.13-rc4' into media_tree

Linux 5.13-rc4

* tag 'v5.13-rc4': (976 commits)
  Linux 5.13-rc4
  seccomp: Refactor notification handler to prepare for new semantics
  selftests: kvm: fix overlapping addresses in memslot_perf_test
  KVM: X86: Kill off ctxt->ud
  KVM: X86: Fix warning caused by stale emulation context
  KVM: X86: Use kvm_get_linear_rip() in single-step and #DB/#BP interception
  Documentation: seccomp: Fix user notification documentation
  MAINTAINERS: adjust to removing i2c designware platform data
  perf vendor events powerpc: Fix eventcode of power10 JSON events
  Revert "serial: 8250: 8250_omap: Fix possible interrupt storm"
  i2c: s3c2410: fix possible NULL pointer deref on read message after write
  i2c: mediatek: Disable i2c start_en and clear intr_stat brfore reset
  perf stat: Fix error check for bpf_program__attach
  cifs: change format of CIFS_FULL_KEY_DUMP ioctl
  i2c: i801: Don't generate an interrupt on bus reset
  i2c: mpc: implement erratum A-004447 workaround
  powerpc/fsl: set fsl,i2c-erratum-a004447 flag for P1010 i2c controllers
  powerpc/fsl: set fsl,i2c-erratum-a004447 flag for P2041 i2c controllers
  dt-bindings: i2c: mpc: Add fsl,i2c-erratum-a004447 flag
  i2c: busses: i2c-stm32f4: Remove incorrectly placed ' ' from function name
  ...

1 files changed, 24 insertions, 5 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 222b1d322c96..ef8cf7619baf 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3853,7 +3853,8 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
 
 	if (q->flags & TCQ_F_NOLOCK) {
 		rc = q->enqueue(skb, q, &to_free) & NET_XMIT_MASK;
-		qdisc_run(q);
+		if (likely(!netif_xmit_frozen_or_stopped(txq)))
+			qdisc_run(q);
 
 		if (unlikely(to_free))
 			kfree_skb_list(to_free);
@@ -5025,25 +5026,43 @@ static __latent_entropy void net_tx_action(struct softirq_action *h)
 		sd->output_queue_tailp = &sd->output_queue;
 		local_irq_enable();
 
+		rcu_read_lock();
+
 		while (head) {
 			struct Qdisc *q = head;
 			spinlock_t *root_lock = NULL;
 
 			head = head->next_sched;
 
-			if (!(q->flags & TCQ_F_NOLOCK)) {
-				root_lock = qdisc_lock(q);
-				spin_lock(root_lock);
-			}
 			/* We need to make sure head->next_sched is read
 			 * before clearing __QDISC_STATE_SCHED
 			 */
 			smp_mb__before_atomic();
+
+			if (!(q->flags & TCQ_F_NOLOCK)) {
+				root_lock = qdisc_lock(q);
+				spin_lock(root_lock);
+			} else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
+						     &q->state))) {
+				/* There is a synchronize_net() between
+				 * STATE_DEACTIVATED flag being set and
+				 * qdisc_reset()/some_qdisc_is_busy() in
+				 * dev_deactivate(), so we can safely bail out
+				 * early here to avoid data race between
+				 * qdisc_deactivate() and some_qdisc_is_busy()
+				 * for lockless qdisc.
+				 */
+				clear_bit(__QDISC_STATE_SCHED, &q->state);
+				continue;
+			}
+
 			clear_bit(__QDISC_STATE_SCHED, &q->state);
 			qdisc_run(q);
 			if (root_lock)
 				spin_unlock(root_lock);
 		}
+
+		rcu_read_unlock();
 	}
 
 	xfrm_dev_backlog(sd);