copy_one_buf() is copying uninitialized stack memory to userspace due to
the compiler not initializing holes in statically allocated structures.
Fix it by initializing `v` with memset().

Cc: sta...@vger.kernel.org
Fixes: 5c7640ab6258 ("switch compat_drm_infobufs() to drm_ioctl_kernel()")
Suggested-by: Dan Carpenter <dan.carpen...@oracle.com>
Signed-off-by: Peilin Ye <yepeilin...@gmail.com>
---
 drivers/gpu/drm/drm_bufs.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index a0735fbc144b..f99cd4a3f951 100644
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -1349,10 +1349,14 @@ static int copy_one_buf(void *data, int count, struct 
drm_buf_entry *from)
 {
        struct drm_buf_info *request = data;
        struct drm_buf_desc __user *to = &request->list[count];
-       struct drm_buf_desc v = {.count = from->buf_count,
-                                .size = from->buf_size,
-                                .low_mark = from->low_mark,
-                                .high_mark = from->high_mark};
+       struct drm_buf_desc v;
+
+       memset(&v, 0, sizeof(v));
+
+       v.count = from->buf_count;
+       v.size = from->buf_size;
+       v.low_mark = from->low_mark;
+       v.high_mark = from->high_mark;
 
        if (copy_to_user(to, &v, offsetof(struct drm_buf_desc, flags)))
                return -EFAULT;
-- 
2.25.1

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