diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2024-06-20 22:56:23 +0200 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2024-06-25 11:10:19 +0200 |
| commit | 22e5751b0524fedd4f345412d8d3394387471ab7 (patch) | |
| tree | 1fb44e4934b36a9e237bb5da8f98fe2d61869d6f /net/unix | |
| parent | af_unix: Remove put_pid()/put_cred() in copy_peercred(). (diff) | |
| download | linux-22e5751b0524fedd4f345412d8d3394387471ab7.tar.xz linux-22e5751b0524fedd4f345412d8d3394387471ab7.zip | |
af_unix: Don't use spin_lock_nested() in copy_peercred().
When (AF_UNIX, SOCK_STREAM) socket connect()s to a listening socket,
the listener's sk_peer_pid/sk_peer_cred are copied to the client in
copy_peercred().
Then, two sk_peer_locks are held there; one is client's and another
is listener's.
However, the latter is not needed because we hold the listner's
unix_state_lock() there and unix_listen() cannot update the cred
concurrently.
Let's drop the unnecessary spin_lock() and use the bare spin_lock()
for the client to protect concurrent read by getsockopt(SO_PEERCRED).
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net/unix')
| -rw-r--r-- | net/unix/af_unix.c | 13 |
1 files changed, 3 insertions, 10 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 3d0ace7ca017..103a7909cb1a 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -772,19 +772,12 @@ static void update_peercred(struct sock *sk) static void copy_peercred(struct sock *sk, struct sock *peersk) { - if (sk < peersk) { - spin_lock(&sk->sk_peer_lock); - spin_lock_nested(&peersk->sk_peer_lock, SINGLE_DEPTH_NESTING); - } else { - spin_lock(&peersk->sk_peer_lock); - spin_lock_nested(&sk->sk_peer_lock, SINGLE_DEPTH_NESTING); - } + lockdep_assert_held(&unix_sk(peersk)->lock); - sk->sk_peer_pid = get_pid(peersk->sk_peer_pid); + spin_lock(&sk->sk_peer_lock); + sk->sk_peer_pid = get_pid(peersk->sk_peer_pid); sk->sk_peer_cred = get_cred(peersk->sk_peer_cred); - spin_unlock(&sk->sk_peer_lock); - spin_unlock(&peersk->sk_peer_lock); } static int unix_listen(struct socket *sock, int backlog) |