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Diffstat (limited to 'net/unix/af_unix.c')
-rw-r--r--net/unix/af_unix.c133
1 files changed, 85 insertions, 48 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index a4631477cedf..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);
@@ -953,32 +953,20 @@ fail:
return NULL;
}
-static int unix_mknod(const char *sun_path, umode_t mode, struct path *res)
+static int unix_mknod(struct dentry *dentry, struct path *path, umode_t mode,
+ struct path *res)
{
- struct dentry *dentry;
- struct path path;
- int err = 0;
- /*
- * Get the parent directory, calculate the hash for last
- * component.
- */
- dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0);
- err = PTR_ERR(dentry);
- if (IS_ERR(dentry))
- return err;
+ int err;
- /*
- * All right, let's create it.
- */
- err = security_path_mknod(&path, dentry, mode, 0);
+ err = security_path_mknod(path, dentry, mode, 0);
if (!err) {
- err = vfs_mknod(d_inode(path.dentry), dentry, mode, 0);
+ err = vfs_mknod(d_inode(path->dentry), dentry, mode, 0);
if (!err) {
- res->mnt = mntget(path.mnt);
+ res->mnt = mntget(path->mnt);
res->dentry = dget(dentry);
}
}
- done_path_create(&path, dentry);
+
return err;
}
@@ -989,10 +977,12 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
struct unix_sock *u = unix_sk(sk);
struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
char *sun_path = sunaddr->sun_path;
- int err;
+ int err, name_err;
unsigned int hash;
struct unix_address *addr;
struct hlist_head *list;
+ struct path path;
+ struct dentry *dentry;
err = -EINVAL;
if (sunaddr->sun_family != AF_UNIX)
@@ -1008,14 +998,34 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
goto out;
addr_len = err;
+ name_err = 0;
+ dentry = NULL;
+ if (sun_path[0]) {
+ /* Get the parent directory, calculate the hash for last
+ * component.
+ */
+ dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0);
+
+ if (IS_ERR(dentry)) {
+ /* delay report until after 'already bound' check */
+ name_err = PTR_ERR(dentry);
+ dentry = NULL;
+ }
+ }
+
err = mutex_lock_interruptible(&u->readlock);
if (err)
- goto out;
+ goto out_path;
err = -EINVAL;
if (u->addr)
goto out_up;
+ if (name_err) {
+ err = name_err == -EEXIST ? -EADDRINUSE : name_err;
+ goto out_up;
+ }
+
err = -ENOMEM;
addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
if (!addr)
@@ -1026,11 +1036,11 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
addr->hash = hash ^ sk->sk_type;
atomic_set(&addr->refcnt, 1);
- if (sun_path[0]) {
- struct path path;
+ if (dentry) {
+ struct path u_path;
umode_t mode = S_IFSOCK |
(SOCK_INODE(sock)->i_mode & ~current_umask());
- err = unix_mknod(sun_path, mode, &path);
+ err = unix_mknod(dentry, &path, mode, &u_path);
if (err) {
if (err == -EEXIST)
err = -EADDRINUSE;
@@ -1038,9 +1048,9 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
goto out_up;
}
addr->hash = UNIX_HASH_SIZE;
- hash = d_backing_inode(path.dentry)->i_ino & (UNIX_HASH_SIZE-1);
+ hash = d_backing_inode(dentry)->i_ino & (UNIX_HASH_SIZE - 1);
spin_lock(&unix_table_lock);
- u->path = path;
+ u->path = u_path;
list = &unix_socket_table[hash];
} else {
spin_lock(&unix_table_lock);
@@ -1063,6 +1073,10 @@ out_unlock:
spin_unlock(&unix_table_lock);
out_up:
mutex_unlock(&u->readlock);
+out_path:
+ if (dentry)
+ done_path_create(&path, dentry);
+
out:
return err;
}
@@ -1499,6 +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)
@@ -1507,6 +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]);
@@ -1528,10 +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;
}
@@ -2078,8 +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;
@@ -2087,30 +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);
@@ -2162,7 +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;
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-07-20 15:23:41 +0200