af_unix: introduce unix_skb_to_scm helper

Instead of open-coding let's consolidate this logic in a separate
helper. This will simplify further changes.

Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Kuniyuki Iwashima <kuniyu@google.com>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Cc: Luca Boccassi <bluca@debian.org>
Cc: David Rheinsberg <david@readahead.eu>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Link: https://lore.kernel.org/20250703222314.309967-3-aleksandr.mikhalitsyn@canonical.com
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index fba50ceab42b3c077cecd4a934b022f6b7aebe5b..df2174d9904dbff4d17797e421152811b951bb47 100644 (file)
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1955,6 +1955,12 @@ static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool sen
        return err;
 }
 
+static void unix_skb_to_scm(struct sk_buff *skb, struct scm_cookie *scm)
+{
+       scm_set_cred(scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
+       unix_set_secdata(scm, skb);
+}
+
 /**
  * unix_maybe_add_creds() - Adds current task uid/gid and struct pid to skb if needed.
  * @skb: skb to attach creds to.
@@ -2565,8 +2571,7 @@ int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
 
        memset(&scm, 0, sizeof(scm));
 
-       scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
-       unix_set_secdata(&scm, skb);
+       unix_skb_to_scm(skb, &scm);
 
        if (!(flags & MSG_PEEK)) {
                if (UNIXCB(skb).fp)
@@ -2951,8 +2956,7 @@ unlock:
                                break;
                } else if (unix_may_passcred(sk)) {
                        /* Copy credentials */
-                       scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
-                       unix_set_secdata(&scm, skb);
+                       unix_skb_to_scm(skb, &scm);
                        check_creds = true;
                }