net/dns_resolver: use credential guards in dns_query()

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

Link: https://patch.msgid.link/20251103-work-creds-guards-simple-v1-16-a3e156839e7f@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2025-11-03 12:27:04 +01:00
parent b66c7af4d8
commit 4037e28cd4
No known key found for this signature in database
GPG Key ID: 91C61BC06578DCA2
1 changed files with 2 additions and 4 deletions

View File

@ -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);