The user space API for the response variable is __u32. This patch makes
sure that the whole path through the kernel uses __u32 so that there is
no sign extension or truncation of the user space response.

Suggested-by: Steve Grubb <sgr...@redhat.com>
Link: https://lore.kernel.org/r/12617626.uLZWGnKmhe@x2
Signed-off-by: Richard Guy Briggs <r...@redhat.com>
Link: 
https://lore.kernel.org/r/aa98a3ad00666a6fc0ce411755de4a1a60f5c0cd.1651174324.git....@redhat.com
---
 fs/notify/fanotify/fanotify.h      | 2 +-
 fs/notify/fanotify/fanotify_user.c | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index a3d5b751cac5..70acfd497771 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -425,7 +425,7 @@ FANOTIFY_PE(struct fanotify_event *event)
 struct fanotify_perm_event {
        struct fanotify_event fae;
        struct path path;
-       unsigned short response;        /* userspace answer to the event */
+       __u32 response;                 /* userspace answer to the event */
        unsigned short state;           /* state of the event */
        int fd;         /* fd we passed to userspace for this event */
 };
diff --git a/fs/notify/fanotify/fanotify_user.c 
b/fs/notify/fanotify/fanotify_user.c
index 9b32b76a9c30..694516470660 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -289,7 +289,7 @@ static int create_fd(struct fsnotify_group *group, struct 
path *path,
  */
 static void finish_permission_event(struct fsnotify_group *group,
                                    struct fanotify_perm_event *event,
-                                   unsigned int response)
+                                   __u32 response)
                                    __releases(&group->notification_lock)
 {
        bool destroy = false;
@@ -310,9 +310,9 @@ static int process_access_response(struct fsnotify_group 
*group,
 {
        struct fanotify_perm_event *event;
        int fd = response_struct->fd;
-       int response = response_struct->response;
+       __u32 response = response_struct->response;
 
-       pr_debug("%s: group=%p fd=%d response=%d\n", __func__, group,
+       pr_debug("%s: group=%p fd=%d response=%u\n", __func__, group,
                 fd, response);
        /*
         * make sure the response is valid, if invalid we do nothing and either
-- 
2.27.0

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