From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Lee Jones <lee.jones@linaro.org>, linux-kernel@vger.kernel.org
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: [PATCH v1 1/1] mfd: Remove software node conditionally and locate at right place
Date: Mon, 10 May 2021 17:15:52 +0300 [thread overview]
Message-ID: <20210510141552.57045-1-andriy.shevchenko@linux.intel.com> (raw)
Currently the software node is removed in error case and at ->remove()
stage unconditionally, that ruins the symmetry. Besides, in some cases,
when mfd_add_device() fails, the device_remove_software_node() call
may lead to NULL pointer dereference:
BUG: kernel NULL pointer dereference, address: 00000000
...
EIP: strlen+0x12/0x20
...
kernfs_name_hash+0x13/0x70
kernfs_find_ns+0x32/0xc0
kernfs_remove_by_name_ns+0x2a/0x90
sysfs_remove_link+0x16/0x30
software_node_notify.cold+0x34/0x6b
device_remove_software_node+0x5a/0x90
mfd_add_device.cold+0x30a/0x427
Fix all these by guarding device_remove_software_node() with a conditional
and locating it at the right place.
Fixes: 42e59982917a ("mfd: core: Add support for software nodes")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
drivers/mfd/mfd-core.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index 6f02b8022c6d..79f5c6a18815 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -266,18 +266,18 @@ static int mfd_add_device(struct device *parent, int id,
if (has_acpi_companion(&pdev->dev)) {
ret = acpi_check_resource_conflict(&res[r]);
if (ret)
- goto fail_of_entry;
+ goto fail_res_conflict;
}
}
}
ret = platform_device_add_resources(pdev, res, cell->num_resources);
if (ret)
- goto fail_of_entry;
+ goto fail_res_conflict;
ret = platform_device_add(pdev);
if (ret)
- goto fail_of_entry;
+ goto fail_res_conflict;
if (cell->pm_runtime_no_callbacks)
pm_runtime_no_callbacks(&pdev->dev);
@@ -286,13 +286,15 @@ static int mfd_add_device(struct device *parent, int id,
return 0;
+fail_res_conflict:
+ if (cell->swnode)
+ device_remove_software_node(&pdev->dev);
fail_of_entry:
list_for_each_entry_safe(of_entry, tmp, &mfd_of_node_list, list)
if (of_entry->dev == &pdev->dev) {
list_del(&of_entry->list);
kfree(of_entry);
}
- device_remove_software_node(&pdev->dev);
fail_alias:
regulator_bulk_unregister_supply_alias(&pdev->dev,
cell->parent_supplies,
@@ -358,11 +360,12 @@ static int mfd_remove_devices_fn(struct device *dev, void *data)
if (level && cell->level > *level)
return 0;
+ if (cell->swnode)
+ device_remove_software_node(&pdev->dev);
+
regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies,
cell->num_parent_supplies);
- device_remove_software_node(&pdev->dev);
-
platform_device_unregister(pdev);
return 0;
}
--
2.30.2
next reply other threads:[~2021-05-10 14:28 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-10 14:15 Andy Shevchenko [this message]
2021-05-19 12:03 ` [PATCH v1 1/1] mfd: Remove software node conditionally and locate at right place Lee Jones
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