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From:   =?UTF-8?q?Vincent=20Stehl=C3=A9?= <vincent.stehle@laposte.net>
To:     devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org
Cc:     =?UTF-8?q?Vincent=20Stehl=C3=A9?= <vincent.stehle@laposte.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: [PATCH] staging: android: vsoc: fix copy_from_user overrun
Date:   Sun, 14 Apr 2019 17:37:26 +0200
Message-Id: <20190414153726.25362-1-vincent.stehle@laposte.net>
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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: 3d2ec9dcd5539d42 ("staging: Android: Add 'vsoc' driver for cuttlefish.")
Signed-off-by: Vincent Stehlé <vincent.stehle@laposte.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 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 8a75bd27c4133..00a1ec7b91549 100644
--- a/drivers/staging/android/vsoc.c
+++ b/drivers/staging/android/vsoc.c
@@ -259,7 +259,8 @@ 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