[PATCH 4.19 311/639] staging: android: vsoc: fix copy_from_user overrun

[Greg Kroah-Hartman]

From: Vincent Stehlà <vincent.stehle@xxxxxxxxxxx>

[ Upstream commit 060ea4271a82270be6d44e8e9aefe8f155fb5626 ]

The `np->permission' structure is smaller than the `np' structure but
sizeof(*np) worth of data is copied in there. Fix the size passed to
copy_from_user() to avoid overrun.

Fixes: 3d2ec9dcd553 ("staging: Android: Add 'vsoc' driver for cuttlefish.")
Signed-off-by: Vincent Stehlà <vincent.stehle@xxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/staging/android/vsoc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/android/vsoc.c b/drivers/staging/android/vsoc.c
index 22571abcaa4e8..034d86869772e 100644
--- a/drivers/staging/android/vsoc.c
+++ b/drivers/staging/android/vsoc.c
@@ -260,7 +260,8 @@ do_create_fd_scoped_permission(struct vsoc_device_region *region_p,
 	atomic_t *owner_ptr = NULL;
 	struct vsoc_device_region *managed_region_p;
 
-	if (copy_from_user(&np->permission, &arg->perm, sizeof(*np)) ||
+	if (copy_from_user(&np->permission,
+			   &arg->perm, sizeof(np->permission)) ||
 	    copy_from_user(&managed_fd,
 			   &arg->managed_region_fd, sizeof(managed_fd))) {
 		return -EFAULT;
-- 
2.20.1