cgroup: avoid pointless cred reference count bump

of->file->f_cred already holds a reference count that is stable during
the operation.

Link: https://lore.kernel.org/r/20241125-work-cred-v2-24-68b9d38bb5b2@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 1a94e8b154beeed45d69056917f3dd9fc6d950fa..d9061bd55436b502e065b477a903ed682d722c2e 100644 (file)
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -5216,11 +5216,11 @@ static ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf,
         * permissions using the credentials from file open to protect against
         * inherited fd attacks.
         */
-       saved_cred = override_creds(get_new_cred(of->file->f_cred));
+       saved_cred = override_creds(of->file->f_cred);
        ret = cgroup_attach_permissions(src_cgrp, dst_cgrp,
                                        of->file->f_path.dentry->d_sb,
                                        threadgroup, ctx->ns);
-       put_cred(revert_creds(saved_cred));
+       revert_creds(saved_cred);
        if (ret)
                goto out_finish;