[PATCH 5.15 260/917] thermal/core: Fix null pointer dereference in thermal_release()

Greg Kroah-Hartman
2021-11-16T01:02:07Z

From: Yuanzheng Song <songyuanzheng@huawei.com>

[ Upstream commit 1dd7128b839f631b31a9e9dce3aaf639bef74e9d ]

If both dev_set_name() and device_register() failed, then null pointer
dereference occurs in thermal_release() which will use strncmp() to
compare the name.

So fix it by adding dev_set_name() return value check.

Signed-off-by: Yuanzheng Song <songyuanzheng@huawei.com>
Link: https://lore.kernel.org/r/20211015083230.67658-1-songyuanzheng@huawei.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/thermal/thermal_core.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 51374f4e1ccaf..d094ebbde0ed7 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -902,6 +902,10 @@ __thermal_cooling_device_register(struct device_node *np,
goto out_kfree_cdev;
cdev->id = ret;

+ ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
+ if (ret)
+ goto out_ida_remove;
+
cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
if (!cdev->type) {
ret = -ENOMEM;
@@ -916,7 +920,6 @@ __thermal_cooling_device_register(struct device_node *np,
cdev->device.class = &thermal_class;
cdev->devdata = devdata;
thermal_cooling_device_setup_sysfs(cdev);
- dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
ret = device_register(&cdev->device);
if (ret)
goto out_kfree_type;
@@ -1227,6 +1230,10 @@ thermal_zone_device_register(const char *type, int trips, int mask,
tz->id = id;
strlcpy(tz->type, type, sizeof(tz->type));

+ result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
+ if (result)
+ goto remove_id;
+
if (!ops->critical)
ops->critical = thermal_zone_device_critical;

@@ -1248,7 +1255,6 @@ thermal_zone_device_register(const char *type, int trips, int mask,
/* A new thermal zone needs to be updated anyway. */
atomic_set(&tz->need_update, 1);

- dev_set_name(&tz->device, "thermal_zone%d", tz->id);
result = device_register(&tz->device);
if (result)
goto release_device;
--
2.33.0