&unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
struct dentry *dentry = unix_sk(s)->path.dentry;
- if (dentry && d_backing_inode(dentry) == i) {
+ if (dentry && d_real_inode(dentry) == i) {
sock_hold(s);
goto found;
}
{
struct unix_sock *u = unix_sk(sk);
- if (mutex_lock_interruptible(&u->readlock))
+ if (mutex_lock_interruptible(&u->iolock))
return -EINTR;
sk->sk_peek_off = val;
- mutex_unlock(&u->readlock);
+ mutex_unlock(&u->iolock);
return 0;
}
spin_lock_init(&u->lock);
atomic_long_set(&u->inflight, 0);
INIT_LIST_HEAD(&u->link);
- mutex_init(&u->readlock); /* single task reading lock */
+ mutex_init(&u->iolock); /* single task reading lock */
+ mutex_init(&u->bindlock); /* single task binding lock */
init_waitqueue_head(&u->peer_wait);
init_waitqueue_func_entry(&u->peer_wake, unix_dgram_peer_wake_relay);
unix_insert_socket(unix_sockets_unbound(sk), sk);
int err;
unsigned int retries = 0;
- err = mutex_lock_interruptible(&u->readlock);
+ err = mutex_lock_interruptible(&u->bindlock);
if (err)
return err;
spin_unlock(&unix_table_lock);
err = 0;
-out: mutex_unlock(&u->readlock);
+out: mutex_unlock(&u->bindlock);
return err;
}
err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path);
if (err)
goto fail;
- inode = d_backing_inode(path.dentry);
+ inode = d_real_inode(path.dentry);
err = inode_permission(inode, MAY_WRITE);
if (err)
goto put_fail;
unsigned int hash;
struct unix_address *addr;
struct hlist_head *list;
+ struct path path = { NULL, NULL };
err = -EINVAL;
if (sunaddr->sun_family != AF_UNIX)
goto out;
addr_len = err;
- err = mutex_lock_interruptible(&u->readlock);
+ if (sun_path[0]) {
+ umode_t mode = S_IFSOCK |
+ (SOCK_INODE(sock)->i_mode & ~current_umask());
+ err = unix_mknod(sun_path, mode, &path);
+ if (err) {
+ if (err == -EEXIST)
+ err = -EADDRINUSE;
+ goto out;
+ }
+ }
+
+ err = mutex_lock_interruptible(&u->bindlock);
if (err)
- goto out;
+ goto out_put;
err = -EINVAL;
if (u->addr)
atomic_set(&addr->refcnt, 1);
if (sun_path[0]) {
- struct path path;
- umode_t mode = S_IFSOCK |
- (SOCK_INODE(sock)->i_mode & ~current_umask());
- err = unix_mknod(sun_path, mode, &path);
- if (err) {
- if (err == -EEXIST)
- err = -EADDRINUSE;
- unix_release_addr(addr);
- goto out_up;
- }
addr->hash = UNIX_HASH_SIZE;
- hash = d_backing_inode(path.dentry)->i_ino & (UNIX_HASH_SIZE-1);
+ hash = d_real_inode(path.dentry)->i_ino & (UNIX_HASH_SIZE - 1);
spin_lock(&unix_table_lock);
u->path = path;
list = &unix_socket_table[hash];
out_unlock:
spin_unlock(&unix_table_lock);
out_up:
- mutex_unlock(&u->readlock);
+ mutex_unlock(&u->bindlock);
+out_put:
+ if (err)
+ path_put(&path);
out:
return err;
}
UNIXCB(skb).fp = NULL;
for (i = scm->fp->count-1; i >= 0; i--)
- unix_notinflight(scm->fp->fp[i]);
+ unix_notinflight(scm->fp->user, scm->fp->fp[i]);
}
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)
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]);
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->user, scm->fp->fp[i]);
return max_level;
}
goto out_unlock;
}
- if (unlikely(unix_peer(other) != sk && unix_recvq_full(other))) {
+ /* other == sk && unix_peer(other) != sk if
+ * - unix_peer(sk) == NULL, destination address bound to sk
+ * - unix_peer(sk) == sk by time of get but disconnected before lock
+ */
+ if (other != sk &&
+ unlikely(unix_peer(other) != sk && unix_recvq_full(other))) {
if (timeo) {
timeo = unix_wait_for_peer(other, timeo);
if (false) {
alloc_skb:
unix_state_unlock(other);
- mutex_unlock(&unix_sk(other)->readlock);
+ mutex_unlock(&unix_sk(other)->iolock);
newskb = sock_alloc_send_pskb(sk, 0, 0, flags & MSG_DONTWAIT,
&err, 0);
if (!newskb)
goto err;
}
- /* we must acquire readlock as we modify already present
+ /* we must acquire iolock as we modify already present
* skbs in the sk_receive_queue and mess with skb->len
*/
- err = mutex_lock_interruptible(&unix_sk(other)->readlock);
+ err = mutex_lock_interruptible(&unix_sk(other)->iolock);
if (err) {
err = flags & MSG_DONTWAIT ? -EAGAIN : -ERESTARTSYS;
goto err;
}
unix_state_unlock(other);
- mutex_unlock(&unix_sk(other)->readlock);
+ mutex_unlock(&unix_sk(other)->iolock);
other->sk_data_ready(other);
scm_destroy(&scm);
err_state_unlock:
unix_state_unlock(other);
err_unlock:
- mutex_unlock(&unix_sk(other)->readlock);
+ mutex_unlock(&unix_sk(other)->iolock);
err:
kfree_skb(newskb);
if (send_sigpipe && !(flags & MSG_NOSIGNAL))
if (flags&MSG_OOB)
goto out;
- err = mutex_lock_interruptible(&u->readlock);
+ err = mutex_lock_interruptible(&u->iolock);
if (unlikely(err)) {
/* recvmsg() in non blocking mode is supposed to return -EAGAIN
* sk_rcvtimeo is not honored by mutex_lock_interruptible()
out_free:
skb_free_datagram(sk, skb);
out_unlock:
- mutex_unlock(&u->readlock);
+ mutex_unlock(&u->iolock);
out:
return err;
}
* Sleep until more data has arrived. But check for races..
*/
static long unix_stream_data_wait(struct sock *sk, long timeo,
- struct sk_buff *last, unsigned int last_len)
+ struct sk_buff *last, unsigned int last_len,
+ bool freezable)
{
struct sk_buff *tail;
DEFINE_WAIT(wait);
sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
unix_state_unlock(sk);
- timeo = freezable_schedule_timeout(timeo);
+ if (freezable)
+ timeo = freezable_schedule_timeout(timeo);
+ else
+ timeo = schedule_timeout(timeo);
unix_state_lock(sk);
if (sock_flag(sk, SOCK_DEAD))
unsigned int splice_flags;
};
-static int unix_stream_read_generic(struct unix_stream_read_state *state)
+static int unix_stream_read_generic(struct unix_stream_read_state *state,
+ bool freezable)
{
struct scm_cookie scm;
struct socket *sock = state->socket;
size_t size = state->size;
unsigned int last_len;
- err = -EINVAL;
- if (sk->sk_state != TCP_ESTABLISHED)
+ if (unlikely(sk->sk_state != TCP_ESTABLISHED)) {
+ err = -EINVAL;
goto out;
+ }
- err = -EOPNOTSUPP;
- if (flags & MSG_OOB)
+ if (unlikely(flags & MSG_OOB)) {
+ err = -EOPNOTSUPP;
goto out;
+ }
target = sock_rcvlowat(sk, flags & MSG_WAITALL, size);
timeo = sock_rcvtimeo(sk, noblock);
/* Lock the socket to prevent queue disordering
* while sleeps in memcpy_tomsg
*/
- mutex_lock(&u->readlock);
+ mutex_lock(&u->iolock);
if (flags & MSG_PEEK)
skip = sk_peek_offset(sk, flags);
goto unlock;
unix_state_unlock(sk);
- err = -EAGAIN;
- if (!timeo)
+ if (!timeo) {
+ err = -EAGAIN;
break;
- mutex_unlock(&u->readlock);
+ }
+
+ mutex_unlock(&u->iolock);
timeo = unix_stream_data_wait(sk, timeo, last,
- last_len);
+ last_len, freezable);
if (signal_pending(current)) {
err = sock_intr_errno(timeo);
+ scm_destroy(&scm);
goto out;
}
- mutex_lock(&u->readlock);
+ mutex_lock(&u->iolock);
continue;
unlock:
unix_state_unlock(sk);
}
} while (size);
- mutex_unlock(&u->readlock);
+ mutex_unlock(&u->iolock);
if (state->msg)
scm_recv(sock, state->msg, &scm, flags);
else
.flags = flags
};
- return unix_stream_read_generic(&state);
+ return unix_stream_read_generic(&state, true);
}
static ssize_t skb_unix_socket_splice(struct sock *sk,
int ret;
struct unix_sock *u = unix_sk(sk);
- mutex_unlock(&u->readlock);
+ mutex_unlock(&u->iolock);
ret = splice_to_pipe(pipe, spd);
- mutex_lock(&u->readlock);
+ mutex_lock(&u->iolock);
return ret;
}
flags & SPLICE_F_NONBLOCK)
state.flags = MSG_DONTWAIT;
- return unix_stream_read_generic(&state);
+ return unix_stream_read_generic(&state, false);
}
static int unix_shutdown(struct socket *sock, int mode)
projects / firefly-linux-kernel-4.4.55.git / blobdiff