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author | Al Viro <viro@ZenIV.linux.org.uk> | 2017-12-05 23:27:57 +0000 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-17 15:07:59 +0100 |
commit | e587b76e655441b7f3239dfb999c444c8573820c (patch) | |
tree | b252a87d76c3374a0704c2d3132c54d1e4ae1e62 | |
parent | fc2f802193ccecf710ab608712b5b102dd9efc75 (diff) | |
download | linux-stable-e587b76e655441b7f3239dfb999c444c8573820c.tar.gz linux-stable-e587b76e655441b7f3239dfb999c444c8573820c.tar.bz2 linux-stable-e587b76e655441b7f3239dfb999c444c8573820c.zip |
fix kcm_clone()
commit a5739435b5a3b8c449f8844ecd71a3b1e89f0a33 upstream.
1) it's fput() or sock_release(), not both
2) don't do fd_install() until the last failure exit.
3) not a bug per se, but... don't attach socket to struct file
until it's set up.
Take reserving descriptor into the caller, move fd_install() to the
caller, sanitize failure exits and calling conventions.
Acked-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | net/kcm/kcmsock.c | 71 |
1 files changed, 27 insertions, 44 deletions
diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c index af4e76ac88ff..c5fa634e63ca 100644 --- a/net/kcm/kcmsock.c +++ b/net/kcm/kcmsock.c @@ -1625,60 +1625,35 @@ static struct proto kcm_proto = { }; /* Clone a kcm socket. */ -static int kcm_clone(struct socket *osock, struct kcm_clone *info, - struct socket **newsockp) +static struct file *kcm_clone(struct socket *osock) { struct socket *newsock; struct sock *newsk; - struct file *newfile; - int err, newfd; + struct file *file; - err = -ENFILE; newsock = sock_alloc(); if (!newsock) - goto out; + return ERR_PTR(-ENFILE); newsock->type = osock->type; newsock->ops = osock->ops; __module_get(newsock->ops->owner); - newfd = get_unused_fd_flags(0); - if (unlikely(newfd < 0)) { - err = newfd; - goto out_fd_fail; - } - - newfile = sock_alloc_file(newsock, 0, osock->sk->sk_prot_creator->name); - if (unlikely(IS_ERR(newfile))) { - err = PTR_ERR(newfile); - goto out_sock_alloc_fail; - } - newsk = sk_alloc(sock_net(osock->sk), PF_KCM, GFP_KERNEL, &kcm_proto, true); if (!newsk) { - err = -ENOMEM; - goto out_sk_alloc_fail; + sock_release(newsock); + return ERR_PTR(-ENOMEM); } - sock_init_data(newsock, newsk); init_kcm_sock(kcm_sk(newsk), kcm_sk(osock->sk)->mux); - fd_install(newfd, newfile); - *newsockp = newsock; - info->fd = newfd; - - return 0; + file = sock_alloc_file(newsock, 0, osock->sk->sk_prot_creator->name); + if (IS_ERR(file)) + sock_release(newsock); -out_sk_alloc_fail: - fput(newfile); -out_sock_alloc_fail: - put_unused_fd(newfd); -out_fd_fail: - sock_release(newsock); -out: - return err; + return file; } static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) @@ -1708,17 +1683,25 @@ static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) } case SIOCKCMCLONE: { struct kcm_clone info; - struct socket *newsock = NULL; - - err = kcm_clone(sock, &info, &newsock); - if (!err) { - if (copy_to_user((void __user *)arg, &info, - sizeof(info))) { - err = -EFAULT; - sys_close(info.fd); - } - } + struct file *file; + + info.fd = get_unused_fd_flags(0); + if (unlikely(info.fd < 0)) + return info.fd; + file = kcm_clone(sock); + if (IS_ERR(file)) { + put_unused_fd(info.fd); + return PTR_ERR(file); + } + if (copy_to_user((void __user *)arg, &info, + sizeof(info))) { + put_unused_fd(info.fd); + fput(file); + return -EFAULT; + } + fd_install(info.fd, file); + err = 0; break; } default: |