phy: cadence: Sierra: fix error handling bugs in probe()

There are two bugs in the error handling:
1: If devm_of_phy_provider_register() fails then there was no cleanup.
2: The error handling called of_node_put(child) improperly leading to
   a use after free.  We are only holding the reference inside the loop
   so the last two gotos after the loop lead to a use after free bug.
   Fix this by cleaning up the partial allocations (or partial iterations)
   in the loop before doing the goto.

Fixes: a43f72ae136a ("phy: cadence: Sierra: Change MAX_LANES of Sierra to 16")
Fixes: 44d30d622821 ("phy: cadence: Add driver for Sierra PHY")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20220115115146.GC7552@kili
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/phy/cadence/phy-cadence-sierra.c b/drivers/phy/cadence/phy-cadence-sierra.c
index da24acd266666a1fc0f03e8c623e08017ffaae9a..e265647e29a249f0336c047fe58b410885c57b3a 100644 (file)
--- a/drivers/phy/cadence/phy-cadence-sierra.c
+++ b/drivers/phy/cadence/phy-cadence-sierra.c
@@ -1338,7 +1338,7 @@ static int cdns_sierra_phy_probe(struct platform_device *pdev)
        struct device *dev = &pdev->dev;
        const struct cdns_sierra_data *data;
        unsigned int id_value;
-       int i, ret, node = 0;
+       int ret, node = 0;
        void __iomem *base;
        struct device_node *dn = dev->of_node, *child;
 
@@ -1416,7 +1416,8 @@ static int cdns_sierra_phy_probe(struct platform_device *pdev)
                        dev_err(dev, "failed to get reset %s\n",
                                child->full_name);
                        ret = PTR_ERR(sp->phys[node].lnk_rst);
-                       goto put_child2;
+                       of_node_put(child);
+                       goto put_control;
                }
 
                if (!sp->autoconf) {
@@ -1424,7 +1425,9 @@ static int cdns_sierra_phy_probe(struct platform_device *pdev)
                        if (ret) {
                                dev_err(dev, "missing property in node %s\n",
                                        child->name);
-                               goto put_child;
+                               of_node_put(child);
+                               reset_control_put(sp->phys[node].lnk_rst);
+                               goto put_control;
                        }
                }
 
@@ -1434,7 +1437,9 @@ static int cdns_sierra_phy_probe(struct platform_device *pdev)
 
                if (IS_ERR(gphy)) {
                        ret = PTR_ERR(gphy);
-                       goto put_child;
+                       of_node_put(child);
+                       reset_control_put(sp->phys[node].lnk_rst);
+                       goto put_control;
                }
                sp->phys[node].phy = gphy;
                phy_set_drvdata(gphy, &sp->phys[node]);
@@ -1446,26 +1451,28 @@ static int cdns_sierra_phy_probe(struct platform_device *pdev)
        if (sp->num_lanes > SIERRA_MAX_LANES) {
                ret = -EINVAL;
                dev_err(dev, "Invalid lane configuration\n");
-               goto put_child2;
+               goto put_control;
        }
 
        /* If more than one subnode, configure the PHY as multilink */
        if (!sp->autoconf && sp->nsubnodes > 1) {
                ret = cdns_sierra_phy_configure_multilink(sp);
                if (ret)
-                       goto put_child2;
+                       goto put_control;
        }
 
        pm_runtime_enable(dev);
        phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
-       return PTR_ERR_OR_ZERO(phy_provider);
-
-put_child:
-       node++;
-put_child2:
-       for (i = 0; i < node; i++)
-               reset_control_put(sp->phys[i].lnk_rst);
-       of_node_put(child);
+       if (IS_ERR(phy_provider)) {
+               ret = PTR_ERR(phy_provider);
+               goto put_control;
+       }
+
+       return 0;
+
+put_control:
+       while (--node >= 0)
+               reset_control_put(sp->phys[node].lnk_rst);
 clk_disable:
        cdns_sierra_phy_disable_clocks(sp);
        reset_control_assert(sp->apb_rst);