Subject: [PATCH 5.7 055/204] pidfd: Add missing sock updates for pidfd_getfd()

From: Greg Kroah-Hartman <[email-masked]>
Date: Thu, 20 Aug 2020 11:19:12 +0200

From: Kees Cook <[email-masked]>

commit 4969f8a073977123504609d7310b42a588297aa4 upstream.

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-masked]>
Cc: Christoph Hellwig <[email-masked]>
Cc: Sargun Dhillon <[email-masked]>
Cc: Jakub Kicinski <[email-masked]>
Cc: [email-masked]
Cc: [email-masked]
Cc: [email-masked]
Fixes: 8649c322f75c ("pid: Implement pidfd_getfd syscall")
Signed-off-by: Kees Cook <[email-masked]>
Signed-off-by: Greg Kroah-Hartman <[email-masked]>

---
 kernel/pid.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/kernel/pid.c
+++ b/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),
@@ -624,10 +625,12 @@ static int pidfd_getfd(struct pid *pid,
 	}
 
 	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;
 }