[PATCH net-next v2 2/6] af_unix: introduce unix_skb_to_scm helper

From: Alexander Mikhalitsyn
Date: Tue Jul 01 2025 - 04:41:03 EST


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

Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: Simon Horman <horms@xxxxxxxxxx>
Cc: Leon Romanovsky <leon@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Cc: Lennart Poettering <mzxreary@xxxxxxxxxxx>
Cc: Luca Boccassi <bluca@xxxxxxxxxx>
Cc: David Rheinsberg <david@xxxxxxxxxxxx>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@xxxxxxxxxxxxx>
Reviewed-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Reviewed-by: Christian Brauner <brauner@xxxxxxxxxx>
---
net/unix/af_unix.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index fba50ceab42b..df2174d9904d 100644
--- 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 @@ static int unix_stream_read_generic(struct unix_stream_read_state *state,
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;
}

--
2.43.0