netdev - [PATCH 16/16] net/dns_resolver: use credential guards in dns

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Message-Id: <20251103-work-creds-guards-simple-v1-16-a3e156839e7f@kernel.org>
Date: Mon, 03 Nov 2025 12:27:04 +0100
From: Christian Brauner <brauner@...nel.org>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org, 
 linux-aio@...ck.org, linux-unionfs@...r.kernel.org, 
 linux-erofs@...ts.ozlabs.org, linux-nfs@...r.kernel.org, 
 linux-cifs@...r.kernel.org, samba-technical@...ts.samba.org, 
 cgroups@...r.kernel.org, netdev@...r.kernel.org, 
 Christian Brauner <brauner@...nel.org>
Subject: [PATCH 16/16] net/dns_resolver: use credential guards in
 dns_query()

Use credential guards for scoped credential override with automatic
restoration on scope exit.

Signed-off-by: Christian Brauner <brauner@...nel.org>
---
 net/dns_resolver/dns_query.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/dns_resolver/dns_query.c b/net/dns_resolver/dns_query.c
index 82b084cc1cc6..53da62984447 100644
--- a/net/dns_resolver/dns_query.c
+++ b/net/dns_resolver/dns_query.c
@@ -78,7 +78,6 @@ int dns_query(struct net *net,
 {
 	struct key *rkey;
 	struct user_key_payload *upayload;
-	const struct cred *saved_cred;
 	size_t typelen, desclen;
 	char *desc, *cp;
 	int ret, len;
@@ -124,9 +123,8 @@ 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(dns_resolver_cache);
-	rkey = request_key_net(&key_type_dns_resolver, desc, net, options);
-	revert_creds(saved_cred);
+	scoped_with_creds(dns_resolver_cache)
+		rkey = request_key_net(&key_type_dns_resolver, desc, net, options);
 	kfree(desc);
 	if (IS_ERR(rkey)) {
 		ret = PTR_ERR(rkey);

-- 
2.47.3