layerscape: add patches-5.4

[openwrt/staging/wigyori.git] / target / linux / layerscape / patches-5.4 / 701-net-0065-sdk_dpaa-ceetm-avoid-use-after-free-scenarios.patch

diff --git a/target/linux/layerscape/patches-5.4/701-net-0065-sdk_dpaa-ceetm-avoid-use-after-free-scenarios.patch b/target/linux/layerscape/patches-5.4/701-net-0065-sdk_dpaa-ceetm-avoid-use-after-free-scenarios.patch
new file mode 100644 (file)
index 0000000..f3d591e
--- /dev/null
+++ b/target/linux/layerscape/patches-5.4/701-net-0065-sdk_dpaa-ceetm-avoid-use-after-free-scenarios.patch
@@ -0,0 +1,67 @@
+From fad6f73dc4367adb852ce6953f93f12cbb97b894 Mon Sep 17 00:00:00 2001
+From: Camelia Groza <camelia.groza@nxp.com>
+Date: Fri, 18 May 2018 10:33:37 +0300
+Subject: [PATCH] sdk_dpaa: ceetm: avoid use-after-free scenarios
+
+Once the pfiofo qdiscs are grafted to the netdev queues, they are destroyed
+by the kernel when required. Remove references to the pfifo qdiscs after
+grafting, in order to avoid double free scenarios.
+
+Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
+---
+ .../ethernet/freescale/sdk_dpaa/dpaa_eth_ceetm.c   | 23 +++++++++++++++++++---
+ 1 file changed, 20 insertions(+), 3 deletions(-)
+
+--- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_ceetm.c
++++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_ceetm.c
+@@ -477,7 +477,9 @@ static void ceetm_destroy(struct Qdisc *
+               if (!priv->root.qdiscs)
+                       break;
+ 
+-              /* Remove the pfifo qdiscs */
++              /* Destroy the pfifo qdiscs in case they haven't been attached
++               * to the netdev queues yet.
++               */
+               for (ntx = 0; ntx < dev->num_tx_queues; ntx++)
+                       if (priv->root.qdiscs[ntx])
+                               qdisc_destroy(priv->root.qdiscs[ntx]);
+@@ -608,7 +610,16 @@ static int ceetm_init_root(struct Qdisc
+               goto err_init_root;
+       }
+ 
+-      /* pre-allocate underlying pfifo qdiscs */
++      /* Pre-allocate underlying pfifo qdiscs.
++       *
++       * We want to offload shaping and scheduling decisions to the hardware.
++       * The pfifo qdiscs will be attached to the netdev queues and will
++       * guide the traffic from the IP stack down to the driver with minimum
++       * interference.
++       *
++       * The CEETM qdiscs and classes will be crossed when the traffic
++       * reaches the driver.
++       */
+       priv->root.qdiscs = kcalloc(dev->num_tx_queues,
+                                   sizeof(priv->root.qdiscs[0]),
+                                   GFP_KERNEL);
+@@ -1280,7 +1291,10 @@ static int ceetm_change(struct Qdisc *sc
+       return ret;
+ }
+ 
+-/* Attach the underlying pfifo qdiscs */
++/* Graft the underlying pfifo qdiscs to the netdev queues.
++ * It's safe to remove our references at this point, since the kernel will
++ * destroy the qdiscs on its own and no cleanup from our part is required.
++ */
+ static void ceetm_attach(struct Qdisc *sch)
+ {
+       struct net_device *dev = qdisc_dev(sch);
+@@ -1296,6 +1310,9 @@ static void ceetm_attach(struct Qdisc *s
+               if (old_qdisc)
+                       qdisc_destroy(old_qdisc);
+       }
++
++      kfree(priv->root.qdiscs);
++      priv->root.qdiscs = NULL;
+ }
+ 
+ static unsigned long ceetm_cls_search(struct Qdisc *sch, u32 handle)