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Diffstat (limited to 'net/unix/af_unix.c')
-rw-r--r--net/unix/af_unix.c67
1 files changed, 45 insertions, 22 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index ef05cd9403d4..c5bf5ef2bf89 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -451,7 +451,7 @@ static void unix_write_space(struct sock *sk)
rcu_read_lock();
if (unix_writable(sk)) {
wq = rcu_dereference(sk->sk_wq);
- if (wq_has_sleeper(wq))
+ if (skwq_has_sleeper(wq))
wake_up_interruptible_sync_poll(&wq->wait,
POLLOUT | POLLWRNORM | POLLWRBAND);
sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
@@ -1513,6 +1513,21 @@ static void unix_destruct_scm(struct sk_buff *skb)
sock_wfree(skb);
}
+/*
+ * The "user->unix_inflight" variable is protected by the garbage
+ * collection lock, and we just read it locklessly here. If you go
+ * over the limit, there might be a tiny race in actually noticing
+ * it across threads. Tough.
+ */
+static inline bool too_many_unix_fds(struct task_struct *p)
+{
+ struct user_struct *user = current_user();
+
+ if (unlikely(user->unix_inflight > task_rlimit(p, RLIMIT_NOFILE)))
+ return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN);
+ return false;
+}
+
#define MAX_RECURSION_LEVEL 4
static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
@@ -1521,6 +1536,9 @@ static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
unsigned char max_level = 0;
int unix_sock_count = 0;
+ if (too_many_unix_fds(current))
+ return -ETOOMANYREFS;
+
for (i = scm->fp->count - 1; i >= 0; i--) {
struct sock *sk = unix_get_socket(scm->fp->fp[i]);
@@ -1542,10 +1560,8 @@ static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
if (!UNIXCB(skb).fp)
return -ENOMEM;
- if (unix_sock_count) {
- for (i = scm->fp->count - 1; i >= 0; i--)
- unix_inflight(scm->fp->fp[i]);
- }
+ for (i = scm->fp->count - 1; i >= 0; i--)
+ unix_inflight(scm->fp->fp[i]);
return max_level;
}
@@ -2092,8 +2108,8 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
struct scm_cookie scm;
struct sock *sk = sock->sk;
struct unix_sock *u = unix_sk(sk);
- int noblock = flags & MSG_DONTWAIT;
- struct sk_buff *skb;
+ struct sk_buff *skb, *last;
+ long timeo;
int err;
int peeked, skip;
@@ -2101,30 +2117,38 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
if (flags&MSG_OOB)
goto out;
- err = mutex_lock_interruptible(&u->readlock);
- if (unlikely(err)) {
- /* recvmsg() in non blocking mode is supposed to return -EAGAIN
- * sk_rcvtimeo is not honored by mutex_lock_interruptible()
- */
- err = noblock ? -EAGAIN : -ERESTARTSYS;
- goto out;
- }
+ timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
- skip = sk_peek_offset(sk, flags);
+ do {
+ mutex_lock(&u->readlock);
- skb = __skb_recv_datagram(sk, flags, &peeked, &skip, &err);
- if (!skb) {
+ skip = sk_peek_offset(sk, flags);
+ skb = __skb_try_recv_datagram(sk, flags, &peeked, &skip, &err,
+ &last);
+ if (skb)
+ break;
+
+ mutex_unlock(&u->readlock);
+
+ if (err != -EAGAIN)
+ break;
+ } while (timeo &&
+ !__skb_wait_for_more_packets(sk, &err, &timeo, last));
+
+ if (!skb) { /* implies readlock unlocked */
unix_state_lock(sk);
/* Signal EOF on disconnected non-blocking SEQPACKET socket. */
if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN &&
(sk->sk_shutdown & RCV_SHUTDOWN))
err = 0;
unix_state_unlock(sk);
- goto out_unlock;
+ goto out;
}
- wake_up_interruptible_sync_poll(&u->peer_wait,
- POLLOUT | POLLWRNORM | POLLWRBAND);
+ if (wq_has_sleeper(&u->peer_wait))
+ wake_up_interruptible_sync_poll(&u->peer_wait,
+ POLLOUT | POLLWRNORM |
+ POLLWRBAND);
if (msg->msg_name)
unix_copy_addr(msg, skb->sk);
@@ -2176,7 +2200,6 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
out_free:
skb_free_datagram(sk, skb);
-out_unlock:
mutex_unlock(&u->readlock);
out:
return err;