linux-kernel - [PATCH v2 26/29] dns_resolver: avoid pointless cred reference count bump

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Message-Id: <20241125-work-cred-v2-26-68b9d38bb5b2@kernel.org>
Date: Mon, 25 Nov 2024 15:10:22 +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 26/29] dns_resolver: avoid pointless cred reference
 count bump

The dns_resolver_cache creds hold a long-term reference that is stable
during the operation.

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

diff --git a/net/dns_resolver/dns_query.c b/net/dns_resolver/dns_query.c
index 0b0789fe2194151102d5234aca3fc2dae9a1ed69..82b084cc1cc6349bb532d5ada555b0bcbb1cdbea 100644
--- a/net/dns_resolver/dns_query.c
+++ b/net/dns_resolver/dns_query.c
@@ -124,9 +124,9 @@ int dns_query(struct net *net,
 	/* make the upcall, using special credentials to prevent the use of
 	 * add_key() to preinstall malicious redirections
 	 */
-	saved_cred = override_creds(get_new_cred(dns_resolver_cache));
+	saved_cred = override_creds(dns_resolver_cache);
 	rkey = request_key_net(&key_type_dns_resolver, desc, net, options);
-	put_cred(revert_creds(saved_cred));
+	revert_creds(saved_cred);
 	kfree(desc);
 	if (IS_ERR(rkey)) {
 		ret = PTR_ERR(rkey);

-- 
2.45.2