From: Lokesh Gidra <lokeshgidra@google.com>
To: Andrea Arcangeli <aarcange@redhat.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
James Morris <jmorris@namei.org>,
Stephen Smalley <stephen.smalley.work@gmail.com>,
Casey Schaufler <casey@schaufler-ca.com>,
Eric Biggers <ebiggers@kernel.org>,
Paul Moore <paul@paul-moore.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>,
Eric Paris <eparis@parisplace.org>,
Lokesh Gidra <lokeshgidra@google.com>,
Daniel Colascione <dancol@dancol.org>,
Kees Cook <keescook@chromium.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
KP Singh <kpsingh@google.com>,
David Howells <dhowells@redhat.com>,
Anders Roxell <anders.roxell@linaro.org>,
Sami Tolvanen <samitolvanen@google.com>,
Matthew Garrett <matthewgarrett@google.com>,
Aaron Goidel <acgoide@tycho.nsa.gov>,
Randy Dunlap <rdunlap@infradead.org>,
"Joel Fernandes (Google)" <joel@joelfernandes.org>,
YueHaibing <yuehaibing@huawei.com>,
Christian Brauner <christian.brauner@ubuntu.com>,
Alexei Starovoitov <ast@kernel.org>,
Alexey Budankov <alexey.budankov@linux.intel.com>,
Adrian Reber <areber@redhat.com>,
Aleksa Sarai <cyphar@cyphar.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org, selinux@vger.kernel.org,
kaleshsingh@google.com, calin@google.com, surenb@google.com,
jeffv@google.com, kernel-team@android.com, linux-mm@kvack.org,
Andrew Morton <akpm@linux-foundation.org>,
hch@infradead.org, Daniel Colascione <dancol@google.com>,
Eric Biggers <ebiggers@google.com>
Subject: [PATCH v13 4/4] userfaultfd: use secure anon inodes for userfaultfd
Date: Wed, 11 Nov 2020 17:53:59 -0800 [thread overview]
Message-ID: <20201112015359.1103333-5-lokeshgidra@google.com> (raw)
In-Reply-To: <20201112015359.1103333-1-lokeshgidra@google.com>
From: Daniel Colascione <dancol@google.com>
This change gives userfaultfd file descriptors a real security
context, allowing policy to act on them.
Signed-off-by: Daniel Colascione <dancol@google.com>
[Remove owner inode from userfaultfd_ctx]
[Use anon_inode_getfd_secure() instead of anon_inode_getfile_secure()
in userfaultfd syscall]
[Use inode of file in userfaultfd_read() in resolve_userfault_fork()]
Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
---
fs/userfaultfd.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 000b457ad087..dd78daf06de6 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -972,14 +972,14 @@ static __poll_t userfaultfd_poll(struct file *file, poll_table *wait)
static const struct file_operations userfaultfd_fops;
-static int resolve_userfault_fork(struct userfaultfd_ctx *ctx,
- struct userfaultfd_ctx *new,
+static int resolve_userfault_fork(struct userfaultfd_ctx *new,
+ struct inode *inode,
struct uffd_msg *msg)
{
int fd;
- fd = anon_inode_getfd("[userfaultfd]", &userfaultfd_fops, new,
- O_RDWR | (new->flags & UFFD_SHARED_FCNTL_FLAGS));
+ fd = anon_inode_getfd_secure("[userfaultfd]", &userfaultfd_fops, new,
+ O_RDWR | (new->flags & UFFD_SHARED_FCNTL_FLAGS), inode);
if (fd < 0)
return fd;
@@ -989,7 +989,7 @@ static int resolve_userfault_fork(struct userfaultfd_ctx *ctx,
}
static ssize_t userfaultfd_ctx_read(struct userfaultfd_ctx *ctx, int no_wait,
- struct uffd_msg *msg)
+ struct uffd_msg *msg, struct inode *inode)
{
ssize_t ret;
DECLARE_WAITQUEUE(wait, current);
@@ -1100,7 +1100,7 @@ static ssize_t userfaultfd_ctx_read(struct userfaultfd_ctx *ctx, int no_wait,
spin_unlock_irq(&ctx->fd_wqh.lock);
if (!ret && msg->event == UFFD_EVENT_FORK) {
- ret = resolve_userfault_fork(ctx, fork_nctx, msg);
+ ret = resolve_userfault_fork(fork_nctx, inode, msg);
spin_lock_irq(&ctx->event_wqh.lock);
if (!list_empty(&fork_event)) {
/*
@@ -1160,6 +1160,7 @@ static ssize_t userfaultfd_read(struct file *file, char __user *buf,
ssize_t _ret, ret = 0;
struct uffd_msg msg;
int no_wait = file->f_flags & O_NONBLOCK;
+ struct inode *inode = file_inode(file);
if (ctx->state == UFFD_STATE_WAIT_API)
return -EINVAL;
@@ -1167,7 +1168,7 @@ static ssize_t userfaultfd_read(struct file *file, char __user *buf,
for (;;) {
if (count < sizeof(msg))
return ret ? ret : -EINVAL;
- _ret = userfaultfd_ctx_read(ctx, no_wait, &msg);
+ _ret = userfaultfd_ctx_read(ctx, no_wait, &msg, inode);
if (_ret < 0)
return ret ? ret : _ret;
if (copy_to_user((__u64 __user *) buf, &msg, sizeof(msg)))
@@ -1985,8 +1986,8 @@ SYSCALL_DEFINE1(userfaultfd, int, flags)
/* prevent the mm struct to be freed */
mmgrab(ctx->mm);
- fd = anon_inode_getfd("[userfaultfd]", &userfaultfd_fops, ctx,
- O_RDWR | (flags & UFFD_SHARED_FCNTL_FLAGS));
+ fd = anon_inode_getfd_secure("[userfaultfd]", &userfaultfd_fops, ctx,
+ O_RDWR | (flags & UFFD_SHARED_FCNTL_FLAGS), NULL);
if (fd < 0) {
mmdrop(ctx->mm);
kmem_cache_free(userfaultfd_ctx_cachep, ctx);
--
2.29.2.299.gdc1121823c-goog
prev parent reply other threads:[~2020-11-12 1:54 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-12 1:53 [PATCH v13 0/4] SELinux support for anonymous inodes and UFFD Lokesh Gidra
2020-11-12 1:53 ` [PATCH v13 1/4] security: add inode_init_security_anon() LSM hook Lokesh Gidra
2020-11-12 1:53 ` [PATCH v13 2/4] fs: add LSM-supporting anon-inode interface Lokesh Gidra
2021-01-07 2:09 ` Paul Moore
2021-01-07 2:42 ` dancol
2021-01-07 3:05 ` Paul Moore
2021-01-07 2:43 ` Lokesh Gidra
2021-01-07 3:08 ` Paul Moore
2020-11-12 1:53 ` [PATCH v13 3/4] selinux: teach SELinux about anonymous inodes Lokesh Gidra
2021-01-07 3:03 ` Paul Moore
2021-01-07 3:55 ` Lokesh Gidra
2021-01-07 22:30 ` Paul Moore
2021-01-07 22:40 ` Lokesh Gidra
2021-01-08 19:35 ` Stephen Smalley
2021-01-08 20:17 ` Lokesh Gidra
2021-01-08 21:23 ` Stephen Smalley
2021-01-08 21:31 ` Lokesh Gidra
2021-01-08 20:58 ` Paul Moore
2020-11-12 1:53 ` Lokesh Gidra [this message]
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=20201112015359.1103333-5-lokeshgidra@google.com \
--to=lokeshgidra@google.com \
--cc=aarcange@redhat.com \
--cc=acgoide@tycho.nsa.gov \
--cc=akpm@linux-foundation.org \
--cc=alexey.budankov@linux.intel.com \
--cc=anders.roxell@linaro.org \
--cc=areber@redhat.com \
--cc=ast@kernel.org \
--cc=calin@google.com \
--cc=casey@schaufler-ca.com \
--cc=christian.brauner@ubuntu.com \
--cc=cyphar@cyphar.com \
--cc=dancol@dancol.org \
--cc=dancol@google.com \
--cc=dhowells@redhat.com \
--cc=ebiederm@xmission.com \
--cc=ebiggers@google.com \
--cc=ebiggers@kernel.org \
--cc=eparis@parisplace.org \
--cc=hch@infradead.org \
--cc=jeffv@google.com \
--cc=jmorris@namei.org \
--cc=joel@joelfernandes.org \
--cc=kaleshsingh@google.com \
--cc=keescook@chromium.org \
--cc=kernel-team@android.com \
--cc=kpsingh@google.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-security-module@vger.kernel.org \
--cc=matthewgarrett@google.com \
--cc=paul@paul-moore.com \
--cc=rdunlap@infradead.org \
--cc=samitolvanen@google.com \
--cc=selinux@vger.kernel.org \
--cc=serge@hallyn.com \
--cc=stephen.smalley.work@gmail.com \
--cc=surenb@google.com \
--cc=viro@zeniv.linux.org.uk \
--cc=yuehaibing@huawei.com \
/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).