From: Dave Airlie <airlied@xxxxxxxxxx>
I think there are limit checks in places for most things but the
new api wants to not have them.
Add a limit check and use the vmemdup_user helper instead.
Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx>
---
drivers/gpu/drm/nouveau/nouveau_drv.h | 19 +++++--------------
1 file changed, 5 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h
index 54063b094a69..8a7357688aff 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drv.h
+++ b/drivers/gpu/drm/nouveau/nouveau_drv.h
@@ -189,21 +189,12 @@ u_free(void *addr)
static inline void *
u_memcpya(uint64_t user, unsigned nmemb, unsigned size)
{
- void *mem;
- void __user *userptr = (void __force __user *)(uintptr_t)user;
+ void __user *userptr = u64_to_user_ptr(user);
+ size_t bytes;
- size *= nmemb;
-
- mem = kvmalloc(size, GFP_KERNEL);
- if (!mem)
- return ERR_PTR(-ENOMEM);
-
- if (copy_from_user(mem, userptr, size)) {
- u_free(mem);
- return ERR_PTR(-EFAULT);
- }
-
- return mem;
+ if (unlikely(check_mul_overflow(nmemb, size, &bytes)))
+ return NULL;
+ return vmemdup_user(userptr, bytes);
}
#include <nvif/object.h>
--
2.41.0
