[PATCH 6/9] drm/nouveau/clk: Move a variable assignment behind a null pointer check in nvkm_pstate_new()

[Markus Elfring]

Date: Sun, 16 Apr 2023 07:45:54 +0200

The address of a data structure member was determined before
a corresponding null pointer check in the implementation of
the function “nvkm_pstate_new”.

Thus avoid the risk for undefined behaviour by moving the assignment
for the variable “cstate” behind the null pointer check.

This issue was detected by using the Coccinelle software.

Fixes: 7c856522069755ab9d163a24ac332cd3cb35fe30 ("drm/nouveau/clk: implement 
power state and engine clock control in core")
Signed-off-by: Markus Elfring <elfr...@users.sourceforge.net>
---
 drivers/gpu/drm/nouveau/nvkm/subdev/clk/base.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/base.c 
b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/base.c
index da07a2fbef06..178dc56909c2 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/base.c
@@ -417,7 +417,6 @@ nvkm_pstate_new(struct nvkm_clk *clk, int idx)
                return 0;

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

@@ -427,6 +426,7 @@ nvkm_pstate_new(struct nvkm_clk *clk, int idx)
        pstate->fanspeed = perfE.fanspeed;
        pstate->pcie_speed = perfE.pcie_speed;
        pstate->pcie_width = perfE.pcie_width;
+       cstate = &pstate->base;
        cstate->voltage = perfE.voltage;
        cstate->domain[nv_clk_src_core] = perfE.core;
        cstate->domain[nv_clk_src_shader] = perfE.shader;
--
2.40.0