diff options
| -rw-r--r-- | include/net/scm.h | 22 | ||||
| -rw-r--r-- | net/unix/af_unix.c | 45 |
2 files changed, 48 insertions, 19 deletions
diff --git a/include/net/scm.h b/include/net/scm.h index 745460fa2f0..68e1e481658 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -53,6 +53,14 @@ static __inline__ void scm_set_cred(struct scm_cookie *scm, cred_to_ucred(pid, cred, &scm->creds); } +static __inline__ void scm_set_cred_noref(struct scm_cookie *scm, + struct pid *pid, const struct cred *cred) +{ + scm->pid = pid; + scm->cred = cred; + cred_to_ucred(pid, cred, &scm->creds); +} + static __inline__ void scm_destroy_cred(struct scm_cookie *scm) { put_pid(scm->pid); @@ -70,6 +78,15 @@ static __inline__ void scm_destroy(struct scm_cookie *scm) __scm_destroy(scm); } +static __inline__ void scm_release(struct scm_cookie *scm) +{ + /* keep ref on pid and cred */ + scm->pid = NULL; + scm->cred = NULL; + if (scm->fp) + __scm_destroy(scm); +} + static __inline__ int scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm) { @@ -108,15 +125,14 @@ static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg, if (!msg->msg_control) { if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp) msg->msg_flags |= MSG_CTRUNC; - scm_destroy(scm); + if (scm && scm->fp) + __scm_destroy(scm); return; } if (test_bit(SOCK_PASSCRED, &sock->flags)) put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(scm->creds), &scm->creds); - scm_destroy_cred(scm); - scm_passec(sock, msg, scm); if (!scm->fp) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index ec68e1c05b8..e6d9d1014ed 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1378,11 +1378,17 @@ static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) return max_level; } -static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds) +static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, + bool send_fds, bool ref) { int err = 0; - UNIXCB(skb).pid = get_pid(scm->pid); - UNIXCB(skb).cred = get_cred(scm->cred); + if (ref) { + UNIXCB(skb).pid = get_pid(scm->pid); + UNIXCB(skb).cred = get_cred(scm->cred); + } else { + UNIXCB(skb).pid = scm->pid; + UNIXCB(skb).cred = scm->cred; + } UNIXCB(skb).fp = NULL; if (scm->fp && send_fds) err = unix_attach_fds(scm, skb); @@ -1407,7 +1413,7 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, int namelen = 0; /* fake GCC */ int err; unsigned hash; - struct sk_buff *skb; + struct sk_buff *skb = NULL; long timeo; struct scm_cookie tmp_scm; int max_level; @@ -1448,7 +1454,7 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, if (skb == NULL) goto out; - err = unix_scm_to_skb(siocb->scm, skb, true); + err = unix_scm_to_skb(siocb->scm, skb, true, false); if (err < 0) goto out_free; max_level = err + 1; @@ -1544,7 +1550,7 @@ restart: unix_state_unlock(other); other->sk_data_ready(other, len); sock_put(other); - scm_destroy(siocb->scm); + scm_release(siocb->scm); return len; out_unlock: @@ -1554,7 +1560,8 @@ out_free: out: if (other) sock_put(other); - scm_destroy(siocb->scm); + if (skb == NULL) + scm_destroy(siocb->scm); return err; } @@ -1566,7 +1573,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, struct sock *sk = sock->sk; struct sock *other = NULL; int err, size; - struct sk_buff *skb; + struct sk_buff *skb = NULL; int sent = 0; struct scm_cookie tmp_scm; bool fds_sent = false; @@ -1631,11 +1638,11 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, size = min_t(int, size, skb_tailroom(skb)); - /* Only send the fds in the first buffer */ - err = unix_scm_to_skb(siocb->scm, skb, !fds_sent); + /* Only send the fds and no ref to pid in the first buffer */ + err = unix_scm_to_skb(siocb->scm, skb, !fds_sent, fds_sent); if (err < 0) { kfree_skb(skb); - goto out_err; + goto out; } max_level = err + 1; fds_sent = true; @@ -1643,7 +1650,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); if (err) { kfree_skb(skb); - goto out_err; + goto out; } unix_state_lock(other); @@ -1660,7 +1667,10 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, sent += size; } - scm_destroy(siocb->scm); + if (skb) + scm_release(siocb->scm); + else + scm_destroy(siocb->scm); siocb->scm = NULL; return sent; @@ -1673,7 +1683,9 @@ pipe_err: send_sig(SIGPIPE, current, 0); err = -EPIPE; out_err: - scm_destroy(siocb->scm); + if (skb == NULL) + scm_destroy(siocb->scm); +out: siocb->scm = NULL; return sent ? : err; } @@ -1777,7 +1789,7 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, siocb->scm = &tmp_scm; memset(&tmp_scm, 0, sizeof(tmp_scm)); } - scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred); + scm_set_cred_noref(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred); unix_set_secdata(siocb->scm, skb); if (!(flags & MSG_PEEK)) { @@ -1939,7 +1951,8 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, } } else { /* Copy credentials */ - scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred); + scm_set_cred_noref(siocb->scm, UNIXCB(skb).pid, + UNIXCB(skb).cred); check_creds = 1; } |