Li Qiang
2025-Nov-06 10:02 UTC
[PATCH] drm/nouveau: Add __GFP_NOFAIL for DSM buffer allocation in r535_disp_oneinit()
acpi_evaluate_dsm() expects a valid buffer pointer for the DSM argument.
The current code uses kmalloc() without checking its return value, which
may lead to a NULL pointer dereference under memory pressure.
Since this buffer is small and there is no recovery path available here,
use __GFP_NOFAIL to guarantee allocation success and avoid potential
kernel crashes.
Fixes: 9e99444490238 ("drm/nouveau/disp/r535: initial support")
Signed-off-by: Li Qiang <liqiang01 at kylinos.cn>
---
drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/disp.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/disp.c
b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/disp.c
index 6e63df816d85..f55ff5dea1c5 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/disp.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/disp.c
@@ -1585,7 +1585,8 @@ r535_disp_oneinit(struct nvkm_disp *disp)
union acpi_object argv4 = {
.buffer.type = ACPI_TYPE_BUFFER,
.buffer.length = sizeof(ctrl->backLightData),
- .buffer.pointer = kmalloc(argv4.buffer.length, GFP_KERNEL),
+ .buffer.pointer = kmalloc(argv4.buffer.length,
+ GFP_KERNEL | __GFP_NOFAIL),
}, *obj;
obj = acpi_evaluate_dsm(handle, nbci ? &NBCI_DSM_GUID :
&NVHG_DSM_GUID,
--
2.25.1