pidfd: Add missing sock updates for pidfd_getfd()

The sock counting (sock_update_netprioidx() and sock_update_classid())
was missing from pidfd's implementation of received fd installation. Add
a call to the new __receive_sock() helper.

Cc: Christian Brauner <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Sargun Dhillon <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Fixes: 8649c32 ("pid: Implement pidfd_getfd syscall")
Signed-off-by: Kees Cook <[email protected]>

Author: kees

kernel/pid.c

@@ -42,6 +42,7 @@
 #include <linux/sched/signal.h>
 #include <linux/sched/task.h>
 #include <linux/idr.h>
+#include <net/sock.h>
 
 struct pid init_struct_pid = {
 	.count		= REFCOUNT_INIT(1),
@@ -642,10 +643,12 @@ static int pidfd_getfd(struct pid *pid, int fd)
 	}
 
 	ret = get_unused_fd_flags(O_CLOEXEC);
-	if (ret < 0)
+	if (ret < 0) {
 		fput(file);
-	else
+	} else {
+		__receive_sock(file);
 		fd_install(ret, file);
+	}
 
 	return ret;
 }