[PATCH 9/9] drm/nouveau/therm: Move an assignment statement behind a null pointer check in two functions

[Markus Elfring]

Date: Sun, 16 Apr 2023 10:50:12 +0200

The address of a data structure member was determined before
a corresponding null pointer check in the implementation of
the functions “nvkm_fanpwm_create” and “nvkm_fantog_create”.

Thus avoid the risk for undefined behaviour by moving the assignment
for the data structure member “fan” behind two null pointer checks.

This issue was detected by using the Coccinelle software.

Fixes: da06b46b720687117178d3ee85a601762f1c36b5 ("drm/nouveau/therm: cosmetic changes")
Signed-off-by: Markus Elfring <elfring at users.sourceforge.net>
---
 drivers/gpu/drm/nouveau/nvkm/subdev/therm/fanpwm.c | 2 +-
 drivers/gpu/drm/nouveau/nvkm/subdev/therm/fantog.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fanpwm.c b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fanpwm.c
index 340f37a299dc..b13ba9b2f6be 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fanpwm.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fanpwm.c
@@ -98,10 +98,10 @@ nvkm_fanpwm_create(struct nvkm_therm *therm, struct dcb_gpio_func *func)
 		return -ENODEV;

 	fan = kzalloc(sizeof(*fan), GFP_KERNEL);
-	therm->fan = &fan->base;
 	if (!fan)
 		return -ENOMEM;

+	therm->fan = &fan->base;
 	fan->base.type = "PWM";
 	fan->base.get = nvkm_fanpwm_get;
 	fan->base.set = nvkm_fanpwm_set;
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fantog.c b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fantog.c
index ff9fbe7950e5..bfdf4ca5625c 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fantog.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fantog.c
@@ -100,10 +100,10 @@ nvkm_fantog_create(struct nvkm_therm *therm, struct dcb_gpio_func *func)
 	}

 	fan = kzalloc(sizeof(*fan), GFP_KERNEL);
-	therm->fan = &fan->base;
 	if (!fan)
 		return -ENOMEM;

+	therm->fan = &fan->base;
 	fan->base.type = "toggle";
 	fan->base.get = nvkm_fantog_get;
 	fan->base.set = nvkm_fantog_set;
--
2.40.0