linux-kernel - [PATCH v2 11/29] binfmt_misc: avoid pointless cred reference count bump

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Message-Id: <20241125-work-cred-v2-11-68b9d38bb5b2@kernel.org>
Date: Mon, 25 Nov 2024 15:10:07 +0100
From: Christian Brauner <brauner@...nel.org>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Amir Goldstein <amir73il@...il.com>, Miklos Szeredi <miklos@...redi.hu>, 
 Al Viro <viro@...iv.linux.org.uk>, Jens Axboe <axboe@...nel.dk>, 
 linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org, 
 Christian Brauner <brauner@...nel.org>
Subject: [PATCH v2 11/29] binfmt_misc: avoid pointless cred reference count
 bump

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

Signed-off-by: Christian Brauner <brauner@...nel.org>
---
 fs/binfmt_misc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index 5692c512b740bb8f11d5da89a2e5f388aafebc13..31660d8cc2c610bd42f00f1de7ed6c39618cc5db 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -826,9 +826,9 @@ static ssize_t bm_register_write(struct file *file, const char __user *buffer,
 		 * didn't matter much as only a privileged process could open
 		 * the register file.
 		 */
-		old_cred = override_creds(get_new_cred(file->f_cred));
+		old_cred = override_creds(file->f_cred);
 		f = open_exec(e->interpreter);
-		put_cred(revert_creds(old_cred));
+		revert_creds(old_cred);
 		if (IS_ERR(f)) {
 			pr_notice("register: failed to install interpreter file %s\n",
 				 e->interpreter);

-- 
2.45.2