From 12f21c49ad83eba93d0485b8c9edcc28201bee93 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Wed, 24 Nov 2021 11:14:26 +0900 Subject: af_unix: Allocate unix_address in unix_bind_(bsd|abstract)(). To terminate address with '\0' in unix_bind_bsd(), we add unix_create_addr() and call it in unix_bind_bsd() and unix_bind_abstract(). Also, unix_bind_abstract() does not return -EEXIST. Only kern_path_create() and vfs_mknod() in unix_bind_bsd() can return it, so we move the last error check in unix_bind() to unix_bind_bsd(). Signed-off-by: Kuniyuki Iwashima Signed-off-by: Jakub Kicinski --- net/unix/af_unix.c | 107 +++++++++++++++++++++++++++++++++-------------------- 1 file changed, 67 insertions(+), 40 deletions(-) (limited to 'net/unix') diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 69782e8e6ad3..2710e7dfc638 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -214,6 +214,22 @@ struct sock *unix_peer_get(struct sock *s) } EXPORT_SYMBOL_GPL(unix_peer_get); +static struct unix_address *unix_create_addr(struct sockaddr_un *sunaddr, + int addr_len) +{ + struct unix_address *addr; + + addr = kmalloc(sizeof(*addr) + addr_len, GFP_KERNEL); + if (!addr) + return NULL; + + refcount_set(&addr->refcnt, 1); + addr->len = addr_len; + memcpy(addr->name, sunaddr, addr_len); + + return addr; +} + static inline void unix_release_addr(struct unix_address *addr) { if (refcount_dec_and_test(&addr->refcnt)) @@ -1083,34 +1099,46 @@ out: mutex_unlock(&u->bindlock); return err; } -static int unix_bind_bsd(struct sock *sk, struct unix_address *addr) +static int unix_bind_bsd(struct sock *sk, struct sockaddr_un *sunaddr, + int addr_len) { - struct unix_sock *u = unix_sk(sk); umode_t mode = S_IFSOCK | (SOCK_INODE(sk->sk_socket)->i_mode & ~current_umask()); + struct unix_sock *u = unix_sk(sk); struct user_namespace *ns; // barf... - struct path parent; + struct unix_address *addr; struct dentry *dentry; + struct path parent; unsigned int hash; int err; + unix_mkname_bsd(sunaddr, addr_len); + addr_len = strlen(sunaddr->sun_path) + + offsetof(struct sockaddr_un, sun_path) + 1; + + addr = unix_create_addr(sunaddr, addr_len); + if (!addr) + return -ENOMEM; + /* * Get the parent directory, calculate the hash for last * component. */ dentry = kern_path_create(AT_FDCWD, addr->name->sun_path, &parent, 0); - if (IS_ERR(dentry)) - return PTR_ERR(dentry); - ns = mnt_user_ns(parent.mnt); + if (IS_ERR(dentry)) { + err = PTR_ERR(dentry); + goto out; + } /* * All right, let's create it. */ + ns = mnt_user_ns(parent.mnt); err = security_path_mknod(&parent, dentry, mode, 0); if (!err) err = vfs_mknod(ns, d_inode(parent.dentry), dentry, mode, 0); if (err) - goto out; + goto out_path; err = mutex_lock_interruptible(&u->bindlock); if (err) goto out_unlink; @@ -1134,47 +1162,61 @@ out_unlock: out_unlink: /* failed after successful mknod? unlink what we'd created... */ vfs_unlink(ns, d_inode(parent.dentry), dentry, NULL); -out: +out_path: done_path_create(&parent, dentry); - return err; +out: + unix_release_addr(addr); + return err == -EEXIST ? -EADDRINUSE : err; } -static int unix_bind_abstract(struct sock *sk, struct unix_address *addr) +static int unix_bind_abstract(struct sock *sk, struct sockaddr_un *sunaddr, + int addr_len) { struct unix_sock *u = unix_sk(sk); + struct unix_address *addr; int err; + addr = unix_create_addr(sunaddr, addr_len); + if (!addr) + return -ENOMEM; + err = mutex_lock_interruptible(&u->bindlock); if (err) - return err; + goto out; if (u->addr) { - mutex_unlock(&u->bindlock); - return -EINVAL; + err = -EINVAL; + goto out_mutex; } addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0)); addr->hash ^= sk->sk_type; spin_lock(&unix_table_lock); + if (__unix_find_socket_byname(sock_net(sk), addr->name, addr->len, - addr->hash)) { - spin_unlock(&unix_table_lock); - mutex_unlock(&u->bindlock); - return -EADDRINUSE; - } + addr->hash)) + goto out_spin; + __unix_set_addr(sk, addr, addr->hash); spin_unlock(&unix_table_lock); mutex_unlock(&u->bindlock); return 0; + +out_spin: + spin_unlock(&unix_table_lock); + err = -EADDRINUSE; +out_mutex: + mutex_unlock(&u->bindlock); +out: + unix_release_addr(addr); + return err; } static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) { struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; - char *sun_path = sunaddr->sun_path; struct sock *sk = sock->sk; - struct unix_address *addr; int err; if (addr_len == offsetof(struct sockaddr_un, sun_path) && @@ -1185,27 +1227,12 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) if (err) return err; - if (sun_path[0]) { - unix_mkname_bsd(sunaddr, addr_len); - addr_len = strlen(sunaddr->sun_path) + - offsetof(struct sockaddr_un, sun_path) + 1; - } - - addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); - if (!addr) - return -ENOMEM; - - memcpy(addr->name, sunaddr, addr_len); - addr->len = addr_len; - refcount_set(&addr->refcnt, 1); - - if (sun_path[0]) - err = unix_bind_bsd(sk, addr); + if (sunaddr->sun_path[0]) + err = unix_bind_bsd(sk, sunaddr, addr_len); else - err = unix_bind_abstract(sk, addr); - if (err) - unix_release_addr(addr); - return err == -EEXIST ? -EADDRINUSE : err; + err = unix_bind_abstract(sk, sunaddr, addr_len); + + return err; } static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) -- cgit