From: Lokesh Gidra <lokeshgidra@google.com>
To: 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>
Cc: "Serge E. Hallyn" <serge@hallyn.com>,
Paul Moore <paul@paul-moore.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>,
Thomas Cedeno <thomascedeno@google.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,
nnk@google.com, jeffv@google.com, kernel-team@android.com,
Daniel Colascione <dancol@google.com>
Subject: [PATCH v8 3/3] Wire UFFD up to SELinux
Date: Wed, 26 Aug 2020 23:35:22 -0700 [thread overview]
Message-ID: <20200827063522.2563293-4-lokeshgidra@google.com> (raw)
In-Reply-To: <20200827063522.2563293-1-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>
---
fs/userfaultfd.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 0e4a3837da52..918535b49475 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -978,14 +978,14 @@ 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;
@@ -995,7 +995,7 @@ 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);
@@ -1106,7 +1106,7 @@ 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)) {
/*
@@ -1166,6 +1166,7 @@ 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;
@@ -1173,7 +1174,7 @@ 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)))
@@ -1995,8 +1996,8 @@ 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);
--
2.28.0.297.g1956fa8f8d-goog
prev parent reply other threads:[~2020-08-27 6:35 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-27 6:35 [PATCH v8 0/3] SELinux support for anonymous inodes and UFFD Lokesh Gidra
2020-08-27 6:35 ` [PATCH v8 1/3] Add a new LSM-supporting anonymous inode interface Lokesh Gidra
2020-09-01 12:41 ` Christian Brauner
2020-09-07 7:45 ` Lokesh Gidra
2020-08-27 6:35 ` [PATCH v8 2/3] Teach SELinux about anonymous inodes Lokesh Gidra
2020-08-31 18:05 ` Stephen Smalley
2020-08-31 18:21 ` Lokesh Gidra
2020-08-27 6:35 ` Lokesh Gidra [this message]
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