From: Kees Cook <keescook@chromium.org>
To: linux-kernel@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>,
Sargun Dhillon <sargun@sargun.me>,
Christian Brauner <christian@brauner.io>,
Tycho Andersen <tycho@tycho.ws>,
David Laight <David.Laight@ACULAB.COM>,
Christoph Hellwig <hch@lst.de>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Aleksa Sarai <cyphar@cyphar.com>,
Matt Denton <mpdenton@google.com>, Jann Horn <jannh@google.com>,
Chris Palmer <palmer@google.com>,
Robert Sesek <rsesek@google.com>,
Giuseppe Scrivano <gscrivan@redhat.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andy Lutomirski <luto@amacapital.net>,
Will Drewry <wad@chromium.org>, Shuah Khan <shuah@kernel.org>,
netdev@vger.kernel.org, containers@lists.linux-foundation.org,
linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kselftest@vger.kernel.org
Subject: [PATCH v5 5/7] fs: Expand __fd_install_received() to accept fd
Date: Wed, 17 Jun 2020 15:03:25 -0700 [thread overview]
Message-ID: <20200617220327.3731559-6-keescook@chromium.org> (raw)
In-Reply-To: <20200617220327.3731559-1-keescook@chromium.org>
Expand __fd_install_received() with support for replace_fd() for the
coming seccomp "addfd" ioctl(). Add new wrapper fd_replace_received()
for the new mode and update existing wrappers to retain old mode.
Signed-off-by: Kees Cook <keescook@chromium.org>
---
fs/file.c | 22 +++++++++++++++++-----
include/linux/file.h | 10 +++++++---
2 files changed, 24 insertions(+), 8 deletions(-)
diff --git a/fs/file.c b/fs/file.c
index de85a42defe2..9568bcfd1f44 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -937,6 +937,7 @@ int replace_fd(unsigned fd, struct file *file, unsigned flags)
/**
* __fd_install_received() - Install received file into file descriptor table
*
+ * @fd: fd to install into (if negative, a new fd will be allocated)
* @file: struct file that was received from another process
* @ufd: __user pointer to write new fd number to
* @o_flags: the O_* flags to apply to the new fd entry
@@ -947,7 +948,8 @@ int replace_fd(unsigned fd, struct file *file, unsigned flags)
*
* Returns newly install fd or -ve on error.
*/
-int __fd_install_received(struct file *file, int __user *ufd, unsigned int o_flags)
+int __fd_install_received(int fd, struct file *file, int __user *ufd,
+ unsigned int o_flags)
{
struct socket *sock;
int new_fd;
@@ -957,9 +959,11 @@ int __fd_install_received(struct file *file, int __user *ufd, unsigned int o_fla
if (error)
return error;
- new_fd = get_unused_fd_flags(o_flags);
- if (new_fd < 0)
- return new_fd;
+ if (fd < 0) {
+ new_fd = get_unused_fd_flags(o_flags);
+ if (new_fd < 0)
+ return new_fd;
+ }
if (ufd) {
error = put_user(new_fd, ufd);
@@ -969,6 +973,15 @@ int __fd_install_received(struct file *file, int __user *ufd, unsigned int o_fla
}
}
+ if (fd < 0)
+ fd_install(new_fd, get_file(file));
+ else {
+ new_fd = fd;
+ error = replace_fd(new_fd, file, o_flags);
+ if (error)
+ return error;
+ }
+
/* Bump the usage count and install the file. The resulting value of
* "error" is ignored here since we only need to take action when
* the file is a socket and testing "sock" for NULL is sufficient.
@@ -978,7 +991,6 @@ int __fd_install_received(struct file *file, int __user *ufd, unsigned int o_fla
sock_update_netprioidx(&sock->sk->sk_cgrp_data);
sock_update_classid(&sock->sk->sk_cgrp_data);
}
- fd_install(new_fd, get_file(file));
return new_fd;
}
diff --git a/include/linux/file.h b/include/linux/file.h
index e19974ed9322..04389b0da11b 100644
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -92,18 +92,22 @@ extern void put_unused_fd(unsigned int fd);
extern void fd_install(unsigned int fd, struct file *file);
-extern int __fd_install_received(struct file *file, int __user *ufd,
+extern int __fd_install_received(int fd, struct file *file, int __user *ufd,
unsigned int o_flags);
static inline int fd_install_received_user(struct file *file, int __user *ufd,
unsigned int o_flags)
{
if (ufd == NULL)
return -EFAULT;
- return __fd_install_received(file, ufd, o_flags);
+ return __fd_install_received(-1, file, ufd, o_flags);
}
static inline int fd_install_received(struct file *file, unsigned int o_flags)
{
- return __fd_install_received(file, NULL, o_flags);
+ return __fd_install_received(-1, file, NULL, o_flags);
+}
+static inline int fd_replace_received(int fd, struct file *file, unsigned int o_flags)
+{
+ return __fd_install_received(fd, file, NULL, o_flags);
}
extern void flush_delayed_fput(void);
--
2.25.1
next prev parent reply other threads:[~2020-06-17 22:03 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-17 22:03 [PATCH v5 0/7] Add seccomp notifier ioctl that enables adding fds Kees Cook
2020-06-17 22:03 ` [PATCH v5 1/7] net/scm: Regularize compat handling of scm_detach_fds() Kees Cook
2020-06-17 22:03 ` [PATCH v5 2/7] fs: Move __scm_install_fd() to __fd_install_received() Kees Cook
2020-06-17 22:03 ` [PATCH v5 3/7] fs: Add fd_install_received() wrapper for __fd_install_received() Kees Cook
2020-06-18 5:49 ` Sargun Dhillon
2020-06-18 20:13 ` Kees Cook
2020-06-19 8:20 ` David Laight
2020-06-17 22:03 ` [PATCH v5 4/7] pidfd: Replace open-coded partial fd_install_received() Kees Cook
2020-07-06 13:07 ` Christian Brauner
2020-07-06 15:34 ` Kees Cook
2020-07-06 16:12 ` Christian Brauner
2020-07-06 16:38 ` Christian Brauner
2020-07-06 19:30 ` Kees Cook
2020-06-17 22:03 ` Kees Cook [this message]
2020-06-17 22:03 ` [PATCH v5 6/7] seccomp: Introduce addfd ioctl to seccomp user notifier Kees Cook
2020-06-17 22:03 ` [PATCH v5 7/7] selftests/seccomp: Test SECCOMP_IOCTL_NOTIF_ADDFD Kees Cook
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200617220327.3731559-6-keescook@chromium.org \
--to=keescook@chromium.org \
--cc=David.Laight@ACULAB.COM \
--cc=christian@brauner.io \
--cc=containers@lists.linux-foundation.org \
--cc=cyphar@cyphar.com \
--cc=davem@davemloft.net \
--cc=gregkh@linuxfoundation.org \
--cc=gscrivan@redhat.com \
--cc=hch@lst.de \
--cc=jannh@google.com \
--cc=kuba@kernel.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=mpdenton@google.com \
--cc=netdev@vger.kernel.org \
--cc=palmer@google.com \
--cc=rsesek@google.com \
--cc=sargun@sargun.me \
--cc=shuah@kernel.org \
--cc=tycho@tycho.ws \
--cc=viro@zeniv.linux.org.uk \
--cc=wad@chromium.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).