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From: Christian Brauner <brauner@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Amir Goldstein <amir73il@gmail.com>,
	Miklos Szeredi <miklos@szeredi.hu>,
	 Al Viro <viro@zeniv.linux.org.uk>, Jens Axboe <axboe@kernel.dk>,
	 linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	 Christian Brauner <brauner@kernel.org>
Subject: [PATCH v2 24/29] cgroup: avoid pointless cred reference count bump
Date: Mon, 25 Nov 2024 15:10:20 +0100	[thread overview]
Message-ID: <20241125-work-cred-v2-24-68b9d38bb5b2@kernel.org> (raw)
In-Reply-To: <20241125-work-cred-v2-0-68b9d38bb5b2@kernel.org>

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

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

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 1a94e8b154beeed45d69056917f3dd9fc6d950fa..d9061bd55436b502e065b477a903ed682d722c2e 100644
--- 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;
 

-- 
2.45.2


  parent reply	other threads:[~2024-11-25 14:11 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-11-25 14:09 [PATCH v2 00/29] cred: rework {override,revert}_creds() Christian Brauner
2024-11-25 14:09 ` [PATCH v2 01/29] tree-wide: s/override_creds()/override_creds_light(get_new_cred())/g Christian Brauner
2024-11-25 14:09 ` [PATCH v2 02/29] cred: return old creds from revert_creds_light() Christian Brauner
2024-11-25 14:09 ` [PATCH v2 03/29] tree-wide: s/revert_creds()/put_cred(revert_creds_light())/g Christian Brauner
2024-11-25 14:10 ` [PATCH v2 04/29] cred: remove old {override,revert}_creds() helpers Christian Brauner
2024-11-25 14:10 ` [PATCH v2 05/29] tree-wide: s/override_creds_light()/override_creds()/g Christian Brauner
2024-11-25 14:10 ` [PATCH v2 06/29] tree-wide: s/revert_creds_light()/revert_creds()/g Christian Brauner
2024-11-25 14:10 ` [PATCH v2 07/29] firmware: avoid pointless reference count bump Christian Brauner
2024-11-25 14:10 ` [PATCH v2 08/29] sev-dev: avoid pointless cred " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 09/29] target_core_configfs: " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 10/29] aio: " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 11/29] binfmt_misc: " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 12/29] coredump: " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 13/29] nfs/localio: avoid pointless cred reference count bumps Christian Brauner
2024-11-25 14:10 ` [PATCH v2 14/29] nfs/nfs4idmap: avoid pointless reference count bump Christian Brauner
2024-11-25 14:10 ` [PATCH v2 15/29] nfs/nfs4recover: avoid pointless cred " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 16/29] nfsfh: " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 17/29] open: " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 18/29] ovl: " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 19/29] cifs: " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 20/29] " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 21/29] smb: " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 22/29] io_uring: " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 23/29] acct: avoid pointless " Christian Brauner
2024-11-25 14:10 ` Christian Brauner [this message]
2024-11-25 14:10 ` [PATCH v2 25/29] trace: avoid pointless cred " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 26/29] dns_resolver: " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 27/29] cachefiles: " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 28/29] nfsd: " Christian Brauner
2024-11-25 14:10 ` [PATCH v2 29/29] cred: remove unused get_new_cred() Christian Brauner
2024-11-25 15:37 ` [PATCH v2 00/29] cred: rework {override,revert}_creds() Chuck Lever
2024-11-25 16:53 ` Linus Torvalds
2024-11-26  9:57 ` Christian Brauner
2024-11-27  2:03 ` Jens Axboe

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