[PATCH v6 4/7] pidfd: Replace open-coded partial receive_fd()

[Kees Cook]

The sock counting (sock_update_netprioidx() and sock_update_classid()) was
missing from pidfd's implementation of received fd installation. Replace
the open-coded version with a call to the new receive_fd()
helper.

Thanks to Vamshi K Sthambamkadi <vamshi.k.sthambamk...@gmail.com> for
catching a missed fput() in an earlier version of this patch.

Fixes: 8649c322f75c ("pid: Implement pidfd_getfd syscall")
Reviewed-by: Sargun Dhillon <sar...@sargun.me>
Signed-off-by: Kees Cook <keesc...@chromium.org>
---
 kernel/pid.c | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/kernel/pid.c b/kernel/pid.c
index f1496b757162..a31c102f4c87 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -635,17 +635,8 @@ static int pidfd_getfd(struct pid *pid, int fd)
        if (IS_ERR(file))
                return PTR_ERR(file);
 
-       ret = security_file_receive(file);
-       if (ret) {
-               fput(file);
-               return ret;
-       }
-
-       ret = get_unused_fd_flags(O_CLOEXEC);
-       if (ret < 0)
-               fput(file);
-       else
-               fd_install(ret, file);
+       ret = receive_fd(file, O_CLOEXEC);
+       fput(file);
 
        return ret;
 }
-- 
2.25.1