Re: [PATCH] nouveau/gsp/r535: Fix a NULL vs error pointer bug

[Danilo Krummrich]

On 11/8/23 08:40, Dan Carpenter wrote:

The r535_gsp_cmdq_get() function returns error pointers but this code
checks for NULL.  Also we need to propagate the error pointer back to
the callers in r535_gsp_rpc_get().  Returning NULL will lead to a NULL
pointer dereference.

Fixes: 176fdcbddfd2 ("drm/nouveau/gsp/r535: add support for booting GSP-RM")
Signed-off-by: Dan Carpenter 


Reviewed-by: Danilo Krummrich 


---
  drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c 
b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c
index e31f9641114b..f8409e2f9fef 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c
@@ -689,8 +689,8 @@ r535_gsp_rpc_get(struct nvkm_gsp *gsp, u32 fn, u32 argc)
struct nvfw_gsp_rpc *rpc;
  
  	rpc = r535_gsp_cmdq_get(gsp, ALIGN(sizeof(*rpc) + argc, sizeof(u64)));

-   if (!rpc)
-   return NULL;
+   if (IS_ERR(rpc))
+   return ERR_CAST(rpc);
  
  	rpc->header_version = 0x0300;

rpc->signature = ('C' << 24) | ('P' << 16) | ('R' << 8) | 'V';

[PATCH] nouveau/gsp/r535: Fix a NULL vs error pointer bug

[Dan Carpenter]

The r535_gsp_cmdq_get() function returns error pointers but this code
checks for NULL.  Also we need to propagate the error pointer back to
the callers in r535_gsp_rpc_get().  Returning NULL will lead to a NULL
pointer dereference.

Fixes: 176fdcbddfd2 ("drm/nouveau/gsp/r535: add support for booting GSP-RM")
Signed-off-by: Dan Carpenter 
---
 drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c 
b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c
index e31f9641114b..f8409e2f9fef 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c
@@ -689,8 +689,8 @@ r535_gsp_rpc_get(struct nvkm_gsp *gsp, u32 fn, u32 argc)
struct nvfw_gsp_rpc *rpc;
 
rpc = r535_gsp_cmdq_get(gsp, ALIGN(sizeof(*rpc) + argc, sizeof(u64)));
-   if (!rpc)
-   return NULL;
+   if (IS_ERR(rpc))
+   return ERR_CAST(rpc);
 
rpc->header_version = 0x0300;
rpc->signature = ('C' << 24) | ('P' << 16) | ('R' << 8) | 'V';
-- 
2.39.2