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Message-ID: <20211122174114.84594-9-kuniyu@amazon.co.jp>
Date: Tue, 23 Nov 2021 02:41:09 +0900
From: Kuniyuki Iwashima <kuniyu@...zon.co.jp>
To: "David S. Miller" <davem@...emloft.net>,
Jakub Kicinski <kuba@...nel.org>
CC: Eric Dumazet <eric.dumazet@...il.com>,
Kuniyuki Iwashima <kuniyu@...zon.co.jp>,
Kuniyuki Iwashima <kuni1840@...il.com>,
"Benjamin Herrenschmidt" <benh@...zon.com>,
<netdev@...r.kernel.org>
Subject: [PATCH RESEND v2 net-next 08/13] 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 <kuniyu@...zon.co.jp>
---
net/unix/af_unix.c | 103 +++++++++++++++++++++++++++------------------
1 file changed, 63 insertions(+), 40 deletions(-)
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 4b56979870dd..8e065c1f00ff 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -214,6 +214,21 @@ 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))
@@ -1079,34 +1094,44 @@ 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;
@@ -1130,47 +1155,59 @@ static int unix_bind_bsd(struct sock *sk, struct unix_address *addr)
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;
- }
+
+ if (__unix_find_socket_byname(sock_net(sk), addr->name, addr->len, 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) &&
@@ -1181,26 +1218,12 @@ 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)
--
2.30.2
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