[PATCH] drm/amdkfd: check for null dev to avoid a null pointer dereference

[Colin King]

From: Colin Ian King <colin.king at canonical.com>

The call to kfd_device_by_id can potentially return null, so check that
dev is null and return with -EINVAL to avoid a null pointer dereference.

Detected by CoverityScan CID#1454629 ("Dereference null return value")

Fixes: 5d71dbc3a588 ("drm/amdkfd: Implement image tiling mode support v2")
Signed-off-by: Colin Ian King <colin.king at canonical.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index e4a8c2e52cb2..660b3fbade41 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -892,6 +892,8 @@ static int kfd_ioctl_get_tile_config(struct file *filep,
 	int err = 0;
 
 	dev = kfd_device_by_id(args->gpu_id);
+	if (!dev)
+		return -EINVAL;
 
 	dev->kfd2kgd->get_tile_config(dev->kgd, &config);
 
-- 
2.14.1