From: Colin Ian King colin.king@canonical.com
Various usif_ioctl helper functions do not initialize the return variable ret and some of the error handling return paths just return garbage values that were on the stack (or in a register). I believe that in all the cases, the initial ret variable should be set to -EINVAL and subsequent paths through these helper functions set it appropriately otherwise.
Found via static analysis using cppcheck:
[drivers/gpu/drm/nouveau/nouveau_usif.c:138]: (error) Uninitialized variable: ret [drivers/gpu/drm/nouveau/nouveau_usif.c:179]: (error) Uninitialized variable: ret [drivers/gpu/drm/nouveau/nouveau_usif.c:202]: (error) Uninitialized variable: ret [drivers/gpu/drm/nouveau/nouveau_usif.c:241]: (error) Uninitialized variable: ret [drivers/gpu/drm/nouveau/nouveau_usif.c:157]: (error) Uninitialized variable: ret [drivers/gpu/drm/nouveau/nouveau_usif.c:288]: (error) Uninitialized variable: ret
Signed-off-by: Colin Ian King colin.king@canonical.com --- drivers/gpu/drm/nouveau/nouveau_usif.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_usif.c b/drivers/gpu/drm/nouveau/nouveau_usif.c index cb1182d..01b50a2 100644 --- a/drivers/gpu/drm/nouveau/nouveau_usif.c +++ b/drivers/gpu/drm/nouveau/nouveau_usif.c @@ -129,7 +129,7 @@ usif_notify_new(struct drm_file *f, void *data, u32 size, void *argv, u32 argc) struct nvif_notify_req_v0 v0; } *req; struct usif_notify *ntfy; - int ret; + int ret = -EINVAL;
if (nvif_unpack(args->v0, 0, 0, true)) { if (usif_notify_find(f, args->v0.index)) @@ -170,7 +170,7 @@ usif_notify_del(struct drm_file *f, void *data, u32 size, void *argv, u32 argc) struct nvif_ioctl_ntfy_del_v0 v0; } *args = data; struct usif_notify *ntfy; - int ret; + int ret = -EINVAL;
if (nvif_unpack(args->v0, 0, 0, true)) { if (!(ntfy = usif_notify_find(f, args->v0.index))) @@ -193,7 +193,7 @@ usif_notify_get(struct drm_file *f, void *data, u32 size, void *argv, u32 argc) struct nvif_ioctl_ntfy_del_v0 v0; } *args = data; struct usif_notify *ntfy; - int ret; + int ret = -EINVAL;
if (nvif_unpack(args->v0, 0, 0, true)) { if (!(ntfy = usif_notify_find(f, args->v0.index))) @@ -232,7 +232,7 @@ usif_notify_put(struct drm_file *f, void *data, u32 size, void *argv, u32 argc) struct nvif_ioctl_ntfy_put_v0 v0; } *args = data; struct usif_notify *ntfy; - int ret; + int ret = -EINVAL;
if (nvif_unpack(args->v0, 0, 0, true)) { if (!(ntfy = usif_notify_find(f, args->v0.index))) @@ -269,7 +269,7 @@ usif_object_new(struct drm_file *f, void *data, u32 size, void *argv, u32 argc) struct nvif_ioctl_new_v0 v0; } *args = data; struct usif_object *object; - int ret; + int ret = -EINVAL;
if (!(object = kmalloc(sizeof(*object), GFP_KERNEL))) return -ENOMEM;