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-rw-r--r--debian/patches/features/all/ena/net-ena-don-t-wake-up-tx-queue-when-down.patch52
1 files changed, 52 insertions, 0 deletions
diff --git a/debian/patches/features/all/ena/net-ena-don-t-wake-up-tx-queue-when-down.patch b/debian/patches/features/all/ena/net-ena-don-t-wake-up-tx-queue-when-down.patch
new file mode 100644
index 000000000..e1b214e80
--- /dev/null
+++ b/debian/patches/features/all/ena/net-ena-don-t-wake-up-tx-queue-when-down.patch
@@ -0,0 +1,52 @@
+From: Sameeh Jubran <sameehj@amazon.com>
+Date: Sun, 15 Sep 2019 17:29:44 +0300
+Subject: [PATCH] net: ena: don't wake up tx queue when down
+Origin: https://git.kernel.org/linus/a53651ec93a8d7ab5b26c5390e0c389048b4b4b6
+Bug-Debian: https://bugs.debian.org/941291
+
+There is a race condition that can occur when calling ena_down().
+The ena_clean_tx_irq() - which is a part of the napi handler -
+function might wake up the tx queue when the queue is supposed
+to be down (during recovery or changing the size of the queues
+for example) This causes the ena_start_xmit() function to trigger
+and possibly try to access the destroyed queues.
+
+The race is illustrated below:
+
+Flow A: Flow B(napi handler)
+ena_down()
+ netif_carrier_off()
+ netif_tx_disable()
+ ena_clean_tx_irq()
+ netif_tx_wake_queue()
+ ena_napi_disable_all()
+ ena_destroy_all_io_queues()
+
+After these flows the tx queue is active and ena_start_xmit() accesses
+the destroyed queue which leads to a kernel panic.
+
+fixes: 1738cd3ed342 (net: ena: Add a driver for Amazon Elastic Network Adapters (ENA))
+
+Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ drivers/net/ethernet/amazon/ena/ena_netdev.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
+index 664e3ed97ea9..d118ed4c57ce 100644
+--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
++++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
+@@ -823,7 +823,8 @@ static int ena_clean_tx_irq(struct ena_ring *tx_ring, u32 budget)
+ above_thresh =
+ ena_com_sq_have_enough_space(tx_ring->ena_com_io_sq,
+ ENA_TX_WAKEUP_THRESH);
+- if (netif_tx_queue_stopped(txq) && above_thresh) {
++ if (netif_tx_queue_stopped(txq) && above_thresh &&
++ test_bit(ENA_FLAG_DEV_UP, &tx_ring->adapter->flags)) {
+ netif_tx_wake_queue(txq);
+ u64_stats_update_begin(&tx_ring->syncp);
+ tx_ring->tx_stats.queue_wakeup++;
+--
+2.17.1
+