| Age | Commit message (Collapse) | Author | Files | Lines |
|---|
|
With the removal of the 'iov' argument to import_single_range(), the two
functions are now fully identical. Convert the import_single_range()
callers to import_ubuf(), and remove the former fully.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20231204174827.1258875-3-axboe@kernel.dk
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
It is entirely unused, just get rid of it.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20231204174827.1258875-2-axboe@kernel.dk
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
If the current task fails the check for the queried capability via
`capable(CAP_SYS_ADMIN)` LSMs like SELinux generate a denial message.
Issuing such denial messages unnecessarily can lead to a policy author
granting more privileges to a subject than needed to silence them.
Reorder CAP_SYS_ADMIN checks after the check whether the operation is
actually privileged.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
|
|
READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.
Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
Drop repeated words in comments.
{to, will, the}
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Ben Boeckel <mathstuf@gmail.com>
Cc: keyrings@vger.kernel.org
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-security-module@vger.kernel.org
|
|
A previous commit changed the notification mode from true/false to an
int, allowing notify-no, notify-yes, or signal-notify. This was
backwards compatible in the sense that any existing true/false user
would translate to either 0 (on notification sent) or 1, the latter
which mapped to TWA_RESUME. TWA_SIGNAL was assigned a value of 2.
Clean this up properly, and define a proper enum for the notification
mode. Now we have:
- TWA_NONE. This is 0, same as before the original change, meaning no
notification requested.
- TWA_RESUME. This is 1, same as before the original change, meaning
that we use TIF_NOTIFY_RESUME.
- TWA_SIGNAL. This uses TIF_SIGPENDING/JOBCTL_TASK_WORK for the
notification.
Clean up all the callers, switching their 0/1/false/true to using the
appropriate TWA_* mode for notifications.
Fixes: e91b48162332 ("task_work: teach task_work_add() to do signal_wake_up()")
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Now that import_iovec handles compat iovecs, the native version of
keyctl_instantiate_key_iov can be used for the compat case as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull notification queue from David Howells:
"This adds a general notification queue concept and adds an event
source for keys/keyrings, such as linking and unlinking keys and
changing their attributes.
Thanks to Debarshi Ray, we do have a pull request to use this to fix a
problem with gnome-online-accounts - as mentioned last time:
https://gitlab.gnome.org/GNOME/gnome-online-accounts/merge_requests/47
Without this, g-o-a has to constantly poll a keyring-based kerberos
cache to find out if kinit has changed anything.
[ There are other notification pending: mount/sb fsinfo notifications
for libmount that Karel Zak and Ian Kent have been working on, and
Christian Brauner would like to use them in lxc, but let's see how
this one works first ]
LSM hooks are included:
- A set of hooks are provided that allow an LSM to rule on whether or
not a watch may be set. Each of these hooks takes a different
"watched object" parameter, so they're not really shareable. The
LSM should use current's credentials. [Wanted by SELinux & Smack]
- A hook is provided to allow an LSM to rule on whether or not a
particular message may be posted to a particular queue. This is
given the credentials from the event generator (which may be the
system) and the watch setter. [Wanted by Smack]
I've provided SELinux and Smack with implementations of some of these
hooks.
WHY
===
Key/keyring notifications are desirable because if you have your
kerberos tickets in a file/directory, your Gnome desktop will monitor
that using something like fanotify and tell you if your credentials
cache changes.
However, we also have the ability to cache your kerberos tickets in
the session, user or persistent keyring so that it isn't left around
on disk across a reboot or logout. Keyrings, however, cannot currently
be monitored asynchronously, so the desktop has to poll for it - not
so good on a laptop. This facility will allow the desktop to avoid the
need to poll.
DESIGN DECISIONS
================
- The notification queue is built on top of a standard pipe. Messages
are effectively spliced in. The pipe is opened with a special flag:
pipe2(fds, O_NOTIFICATION_PIPE);
The special flag has the same value as O_EXCL (which doesn't seem
like it will ever be applicable in this context)[?]. It is given up
front to make it a lot easier to prohibit splice&co from accessing
the pipe.
[?] Should this be done some other way? I'd rather not use up a new
O_* flag if I can avoid it - should I add a pipe3() system call
instead?
The pipe is then configured::
ioctl(fds[1], IOC_WATCH_QUEUE_SET_SIZE, queue_depth);
ioctl(fds[1], IOC_WATCH_QUEUE_SET_FILTER, &filter);
Messages are then read out of the pipe using read().
- It should be possible to allow write() to insert data into the
notification pipes too, but this is currently disabled as the
kernel has to be able to insert messages into the pipe *without*
holding pipe->mutex and the code to make this work needs careful
auditing.
- sendfile(), splice() and vmsplice() are disabled on notification
pipes because of the pipe->mutex issue and also because they
sometimes want to revert what they just did - but one or more
notification messages might've been interleaved in the ring.
- The kernel inserts messages with the wait queue spinlock held. This
means that pipe_read() and pipe_write() have to take the spinlock
to update the queue pointers.
- Records in the buffer are binary, typed and have a length so that
they can be of varying size.
This allows multiple heterogeneous sources to share a common
buffer; there are 16 million types available, of which I've used
just a few, so there is scope for others to be used. Tags may be
specified when a watchpoint is created to help distinguish the
sources.
- Records are filterable as types have up to 256 subtypes that can be
individually filtered. Other filtration is also available.
- Notification pipes don't interfere with each other; each may be
bound to a different set of watches. Any particular notification
will be copied to all the queues that are currently watching for it
- and only those that are watching for it.
- When recording a notification, the kernel will not sleep, but will
rather mark a queue as having lost a message if there's
insufficient space. read() will fabricate a loss notification
message at an appropriate point later.
- The notification pipe is created and then watchpoints are attached
to it, using one of:
keyctl_watch_key(KEY_SPEC_SESSION_KEYRING, fds[1], 0x01);
watch_mount(AT_FDCWD, "/", 0, fd, 0x02);
watch_sb(AT_FDCWD, "/mnt", 0, fd, 0x03);
where in both cases, fd indicates the queue and the number after is
a tag between 0 and 255.
- Watches are removed if either the notification pipe is destroyed or
the watched object is destroyed. In the latter case, a message will
be generated indicating the enforced watch removal.
Things I want to avoid:
- Introducing features that make the core VFS dependent on the
network stack or networking namespaces (ie. usage of netlink).
- Dumping all this stuff into dmesg and having a daemon that sits
there parsing the output and distributing it as this then puts the
responsibility for security into userspace and makes handling
namespaces tricky. Further, dmesg might not exist or might be
inaccessible inside a container.
- Letting users see events they shouldn't be able to see.
TESTING AND MANPAGES
====================
- The keyutils tree has a pipe-watch branch that has keyctl commands
for making use of notifications. Proposed manual pages can also be
found on this branch, though a couple of them really need to go to
the main manpages repository instead.
If the kernel supports the watching of keys, then running "make
test" on that branch will cause the testing infrastructure to spawn
a monitoring process on the side that monitors a notifications pipe
for all the key/keyring changes induced by the tests and they'll
all be checked off to make sure they happened.
https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/keyutils.git/log/?h=pipe-watch
- A test program is provided (samples/watch_queue/watch_test) that
can be used to monitor for keyrings, mount and superblock events.
Information on the notifications is simply logged to stdout"
* tag 'notifications-20200601' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
smack: Implement the watch_key and post_notification hooks
selinux: Implement the watch_key security hook
keys: Make the KEY_NEED_* perms an enum rather than a mask
pipe: Add notification lossage handling
pipe: Allow buffers to be marked read-whole-or-error for notifications
Add sample notification program
watch_queue: Add a key/keyring notification facility
security: Add hooks to rule on setting a watch
pipe: Add general notification queue support
pipe: Add O_NOTIFICATION_PIPE
security: Add a hook for the point of notification insertion
uapi: General notification queue definitions
|
|
Convert comments that reference mmap_sem to reference mmap_lock instead.
[akpm@linux-foundation.org: fix up linux-next leftovers]
[akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
[akpm@linux-foundation.org: more linux-next fixups, per Michel]
Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
For kvmalloc'ed data object that contains sensitive information like
cryptographic keys, we need to make sure that the buffer is always cleared
before freeing it. Using memset() alone for buffer clearing may not
provide certainty as the compiler may compile it away. To be sure, the
special memzero_explicit() has to be used.
This patch introduces a new kvfree_sensitive() for freeing those sensitive
data objects allocated by kvmalloc(). The relevant places where
kvfree_sensitive() can be used are modified to use it.
Fixes: 4f0882491a14 ("KEYS: Avoid false positive ENOMEM error on key read")
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Link: http://lkml.kernel.org/r/20200407200318.11711-1-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Since the meaning of combining the KEY_NEED_* constants is undefined, make
it so that you can't do that by turning them into an enum.
The enum is also given some extra values to represent special
circumstances, such as:
(1) The '0' value is reserved and causes a warning to trap the parameter
being unset.
(2) The key is to be unlinked and we require no permissions on it, only
the keyring, (this replaces the KEY_LOOKUP_FOR_UNLINK flag).
(3) An override due to CAP_SYS_ADMIN.
(4) An override due to an instantiation token being present.
(5) The permissions check is being deferred to later key_permission()
calls.
The extra values give the opportunity for LSMs to audit these situations.
[Note: This really needs overhauling so that lookup_user_key() tells
key_task_permission() and the LSM what operation is being done and leaves
it to those functions to decide how to map that onto the available
permits. However, I don't really want to make these change in the middle
of the notifications patchset.]
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
cc: Paul Moore <paul@paul-moore.com>
cc: Stephen Smalley <stephen.smalley.work@gmail.com>
cc: Casey Schaufler <casey@schaufler-ca.com>
cc: keyrings@vger.kernel.org
cc: selinux@vger.kernel.org
|
|
Add a key/keyring change notification facility whereby notifications about
changes in key and keyring content and attributes can be received.
Firstly, an event queue needs to be created:
pipe2(fds, O_NOTIFICATION_PIPE);
ioctl(fds[1], IOC_WATCH_QUEUE_SET_SIZE, 256);
then a notification can be set up to report notifications via that queue:
struct watch_notification_filter filter = {
.nr_filters = 1,
.filters = {
[0] = {
.type = WATCH_TYPE_KEY_NOTIFY,
.subtype_filter[0] = UINT_MAX,
},
},
};
ioctl(fds[1], IOC_WATCH_QUEUE_SET_FILTER, &filter);
keyctl_watch_key(KEY_SPEC_SESSION_KEYRING, fds[1], 0x01);
After that, records will be placed into the queue when events occur in
which keys are changed in some way. Records are of the following format:
struct key_notification {
struct watch_notification watch;
__u32 key_id;
__u32 aux;
} *n;
Where:
n->watch.type will be WATCH_TYPE_KEY_NOTIFY.
n->watch.subtype will indicate the type of event, such as
NOTIFY_KEY_REVOKED.
n->watch.info & WATCH_INFO_LENGTH will indicate the length of the
record.
n->watch.info & WATCH_INFO_ID will be the second argument to
keyctl_watch_key(), shifted.
n->key will be the ID of the affected key.
n->aux will hold subtype-dependent information, such as the key
being linked into the keyring specified by n->key in the case of
NOTIFY_KEY_LINKED.
Note that it is permissible for event records to be of variable length -
or, at least, the length may be dependent on the subtype. Note also that
the queue can be shared between multiple notifications of various types.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull keyrings fixes from David Howells:
"Here's a couple of patches that fix a circular dependency between
holding key->sem and mm->mmap_sem when reading data from a key.
One potential issue is that a filesystem looking to use a key inside,
say, ->readpages() could deadlock if the key being read is the key
that's required and the buffer the key is being read into is on a page
that needs to be fetched.
The case actually detected is a bit more involved - with a filesystem
calling request_key() and locking the target keyring for write - which
could be being read"
* tag 'keys-fixes-20200329' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
KEYS: Avoid false positive ENOMEM error on key read
KEYS: Don't write out to userspace while holding key semaphore
|
|
By allocating a kernel buffer with a user-supplied buffer length, it
is possible that a false positive ENOMEM error may be returned because
the user-supplied length is just too large even if the system do have
enough memory to hold the actual key data.
Moreover, if the buffer length is larger than the maximum amount of
memory that can be returned by kmalloc() (2^(MAX_ORDER-1) number of
pages), a warning message will also be printed.
To reduce this possibility, we set a threshold (PAGE_SIZE) over which we
do check the actual key length first before allocating a buffer of the
right size to hold it. The threshold is arbitrary, it is just used to
trigger a buffer length check. It does not limit the actual key length
as long as there is enough memory to satisfy the memory request.
To further avoid large buffer allocation failure due to page
fragmentation, kvmalloc() is used to allocate the buffer so that vmapped
pages can be used when there is not a large enough contiguous set of
pages available for allocation.
In the extremely unlikely scenario that the key keeps on being changed
and made longer (still <= buflen) in between 2 __keyctl_read_key()
calls, the __keyctl_read_key() calling loop in keyctl_read_key() may
have to be iterated a large number of times, but definitely not infinite.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
A lockdep circular locking dependency report was seen when running a
keyutils test:
[12537.027242] ======================================================
[12537.059309] WARNING: possible circular locking dependency detected
[12537.088148] 4.18.0-147.7.1.el8_1.x86_64+debug #1 Tainted: G OE --------- - -
[12537.125253] ------------------------------------------------------
[12537.153189] keyctl/25598 is trying to acquire lock:
[12537.175087] 000000007c39f96c (&mm->mmap_sem){++++}, at: __might_fault+0xc4/0x1b0
[12537.208365]
[12537.208365] but task is already holding lock:
[12537.234507] 000000003de5b58d (&type->lock_class){++++}, at: keyctl_read_key+0x15a/0x220
[12537.270476]
[12537.270476] which lock already depends on the new lock.
[12537.270476]
[12537.307209]
[12537.307209] the existing dependency chain (in reverse order) is:
[12537.340754]
[12537.340754] -> #3 (&type->lock_class){++++}:
[12537.367434] down_write+0x4d/0x110
[12537.385202] __key_link_begin+0x87/0x280
[12537.405232] request_key_and_link+0x483/0xf70
[12537.427221] request_key+0x3c/0x80
[12537.444839] dns_query+0x1db/0x5a5 [dns_resolver]
[12537.468445] dns_resolve_server_name_to_ip+0x1e1/0x4d0 [cifs]
[12537.496731] cifs_reconnect+0xe04/0x2500 [cifs]
[12537.519418] cifs_readv_from_socket+0x461/0x690 [cifs]
[12537.546263] cifs_read_from_socket+0xa0/0xe0 [cifs]
[12537.573551] cifs_demultiplex_thread+0x311/0x2db0 [cifs]
[12537.601045] kthread+0x30c/0x3d0
[12537.617906] ret_from_fork+0x3a/0x50
[12537.636225]
[12537.636225] -> #2 (root_key_user.cons_lock){+.+.}:
[12537.664525] __mutex_lock+0x105/0x11f0
[12537.683734] request_key_and_link+0x35a/0xf70
[12537.705640] request_key+0x3c/0x80
[12537.723304] dns_query+0x1db/0x5a5 [dns_resolver]
[12537.746773] dns_resolve_server_name_to_ip+0x1e1/0x4d0 [cifs]
[12537.775607] cifs_reconnect+0xe04/0x2500 [cifs]
[12537.798322] cifs_readv_from_socket+0x461/0x690 [cifs]
[12537.823369] cifs_read_from_socket+0xa0/0xe0 [cifs]
[12537.847262] cifs_demultiplex_thread+0x311/0x2db0 [cifs]
[12537.873477] kthread+0x30c/0x3d0
[12537.890281] ret_from_fork+0x3a/0x50
[12537.908649]
[12537.908649] -> #1 (&tcp_ses->srv_mutex){+.+.}:
[12537.935225] __mutex_lock+0x105/0x11f0
[12537.954450] cifs_call_async+0x102/0x7f0 [cifs]
[12537.977250] smb2_async_readv+0x6c3/0xc90 [cifs]
[12538.000659] cifs_readpages+0x120a/0x1e50 [cifs]
[12538.023920] read_pages+0xf5/0x560
[12538.041583] __do_page_cache_readahead+0x41d/0x4b0
[12538.067047] ondemand_readahead+0x44c/0xc10
[12538.092069] filemap_fault+0xec1/0x1830
[12538.111637] __do_fault+0x82/0x260
[12538.129216] do_fault+0x419/0xfb0
[12538.146390] __handle_mm_fault+0x862/0xdf0
[12538.167408] handle_mm_fault+0x154/0x550
[12538.187401] __do_page_fault+0x42f/0xa60
[12538.207395] do_page_fault+0x38/0x5e0
[12538.225777] page_fault+0x1e/0x30
[12538.243010]
[12538.243010] -> #0 (&mm->mmap_sem){++++}:
[12538.267875] lock_acquire+0x14c/0x420
[12538.286848] __might_fault+0x119/0x1b0
[12538.306006] keyring_read_iterator+0x7e/0x170
[12538.327936] assoc_array_subtree_iterate+0x97/0x280
[12538.352154] keyring_read+0xe9/0x110
[12538.370558] keyctl_read_key+0x1b9/0x220
[12538.391470] do_syscall_64+0xa5/0x4b0
[12538.410511] entry_SYSCALL_64_after_hwframe+0x6a/0xdf
[12538.435535]
[12538.435535] other info that might help us debug this:
[12538.435535]
[12538.472829] Chain exists of:
[12538.472829] &mm->mmap_sem --> root_key_user.cons_lock --> &type->lock_class
[12538.472829]
[12538.524820] Possible unsafe locking scenario:
[12538.524820]
[12538.551431] CPU0 CPU1
[12538.572654] ---- ----
[12538.595865] lock(&type->lock_class);
[12538.613737] lock(root_key_user.cons_lock);
[12538.644234] lock(&type->lock_class);
[12538.672410] lock(&mm->mmap_sem);
[12538.687758]
[12538.687758] *** DEADLOCK ***
[12538.687758]
[12538.714455] 1 lock held by keyctl/25598:
[12538.732097] #0: 000000003de5b58d (&type->lock_class){++++}, at: keyctl_read_key+0x15a/0x220
[12538.770573]
[12538.770573] stack backtrace:
[12538.790136] CPU: 2 PID: 25598 Comm: keyctl Kdump: loaded Tainted: G
[12538.844855] Hardware name: HP ProLiant DL360 Gen9/ProLiant DL360 Gen9, BIOS P89 12/27/2015
[12538.881963] Call Trace:
[12538.892897] dump_stack+0x9a/0xf0
[12538.907908] print_circular_bug.isra.25.cold.50+0x1bc/0x279
[12538.932891] ? save_trace+0xd6/0x250
[12538.948979] check_prev_add.constprop.32+0xc36/0x14f0
[12538.971643] ? keyring_compare_object+0x104/0x190
[12538.992738] ? check_usage+0x550/0x550
[12539.009845] ? sched_clock+0x5/0x10
[12539.025484] ? sched_clock_cpu+0x18/0x1e0
[12539.043555] __lock_acquire+0x1f12/0x38d0
[12539.061551] ? trace_hardirqs_on+0x10/0x10
[12539.080554] lock_acquire+0x14c/0x420
[12539.100330] ? __might_fault+0xc4/0x1b0
[12539.119079] __might_fault+0x119/0x1b0
[12539.135869] ? __might_fault+0xc4/0x1b0
[12539.153234] keyring_read_iterator+0x7e/0x170
[12539.172787] ? keyring_read+0x110/0x110
[12539.190059] assoc_array_subtree_iterate+0x97/0x280
[12539.211526] keyring_read+0xe9/0x110
[12539.227561] ? keyring_gc_check_iterator+0xc0/0xc0
[12539.249076] keyctl_read_key+0x1b9/0x220
[12539.266660] do_syscall_64+0xa5/0x4b0
[12539.283091] entry_SYSCALL_64_after_hwframe+0x6a/0xdf
One way to prevent this deadlock scenario from happening is to not
allow writing to userspace while holding the key semaphore. Instead,
an internal buffer is allocated for getting the keys out from the
read method first before copying them out to userspace without holding
the lock.
That requires taking out the __user modifier from all the relevant
read methods as well as additional changes to not use any userspace
write helpers. That is,
1) The put_user() call is replaced by a direct copy.
2) The copy_to_user() call is replaced by memcpy().
3) All the fault handling code is removed.
Compiling on a x86-64 system, the size of the rxrpc_read() function is
reduced from 3795 bytes to 2384 bytes with this patch.
Fixes: ^1da177e4c3f4 ("Linux-2.6.12-rc2")
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
Currently, when we add a new user key, the calltrace as below:
add_key()
key_create_or_update()
key_alloc()
__key_instantiate_and_link
generic_key_instantiate
key_payload_reserve
......
Since commit a08bf91ce28e ("KEYS: allow reaching the keys quotas exactly"),
we can reach max bytes/keys in key_alloc, but we forget to remove this
limit when we reserver space for payload in key_payload_reserve. So we
can only reach max keys but not max bytes when having delta between plen
and type->def_datalen. Remove this limit when instantiating the key, so we
can keep consistent with key_alloc.
Also, fix the similar problem in keyctl_chown_key().
Fixes: 0b77f5bfb45c ("keys: make the keyring quotas controllable through /proc/sys")
Fixes: a08bf91ce28e ("KEYS: allow reaching the keys quotas exactly")
Cc: stable@vger.kernel.org # 5.0.x
Cc: Eric Biggers <ebiggers@google.com>
Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs"
This reverts merge 0f75ef6a9cff49ff612f7ce0578bced9d0b38325 (and thus
effectively commits
7a1ade847596 ("keys: Provide KEYCTL_GRANT_PERMISSION")
2e12256b9a76 ("keys: Replace uid/gid/perm permissions checking with an ACL")
that the merge brought in).
It turns out that it breaks booting with an encrypted volume, and Eric
biggers reports that it also breaks the fscrypt tests [1] and loading of
in-kernel X.509 certificates [2].
The root cause of all the breakage is likely the same, but David Howells
is off email so rather than try to work it out it's getting reverted in
order to not impact the rest of the merge window.
[1] https://lore.kernel.org/lkml/20190710011559.GA7973@sol.localdomain/
[2] https://lore.kernel.org/lkml/20190710013225.GB7973@sol.localdomain/
Link: https://lore.kernel.org/lkml/CAHk-=wjxoeMJfeBahnWH=9zShKp2bsVy527vo3_y8HfOdhwAAw@mail.gmail.com/
Reported-by: Eric Biggers <ebiggers@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull keyring ACL support from David Howells:
"This changes the permissions model used by keys and keyrings to be
based on an internal ACL by the following means:
- Replace the permissions mask internally with an ACL that contains a
list of ACEs, each with a specific subject with a permissions mask.
Potted default ACLs are available for new keys and keyrings.
ACE subjects can be macroised to indicate the UID and GID specified
on the key (which remain). Future commits will be able to add
additional subject types, such as specific UIDs or domain
tags/namespaces.
Also split a number of permissions to give finer control. Examples
include splitting the revocation permit from the change-attributes
permit, thereby allowing someone to be granted permission to revoke
a key without allowing them to change the owner; also the ability
to join a keyring is split from the ability to link to it, thereby
stopping a process accessing a keyring by joining it and thus
acquiring use of possessor permits.
- Provide a keyctl to allow the granting or denial of one or more
permits to a specific subject. Direct access to the ACL is not
granted, and the ACL cannot be viewed"
* tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
keys: Provide KEYCTL_GRANT_PERMISSION
keys: Replace uid/gid/perm permissions checking with an ACL
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull keyring namespacing from David Howells:
"These patches help make keys and keyrings more namespace aware.
Firstly some miscellaneous patches to make the process easier:
- Simplify key index_key handling so that the word-sized chunks
assoc_array requires don't have to be shifted about, making it
easier to add more bits into the key.
- Cache the hash value in the key so that we don't have to calculate
on every key we examine during a search (it involves a bunch of
multiplications).
- Allow keying_search() to search non-recursively.
Then the main patches:
- Make it so that keyring names are per-user_namespace from the point
of view of KEYCTL_JOIN_SESSION_KEYRING so that they're not
accessible cross-user_namespace.
keyctl_capabilities() shows KEYCTL_CAPS1_NS_KEYRING_NAME for this.
- Move the user and user-session keyrings to the user_namespace
rather than the user_struct. This prevents them propagating
directly across user_namespaces boundaries (ie. the KEY_SPEC_*
flags will only pick from the current user_namespace).
- Make it possible to include the target namespace in which the key
shall operate in the index_key. This will allow the possibility of
multiple keys with the same description, but different target
domains to be held in the same keyring.
keyctl_capabilities() shows KEYCTL_CAPS1_NS_KEY_TAG for this.
- Make it so that keys are implicitly invalidated by removal of a
domain tag, causing them to be garbage collected.
- Institute a network namespace domain tag that allows keys to be
differentiated by the network namespace in which they operate. New
keys that are of a type marked 'KEY_TYPE_NET_DOMAIN' are assigned
the network domain in force when they are created.
- Make it so that the desired network namespace can be handed down
into the request_key() mechanism. This allows AFS, NFS, etc. to
request keys specific to the network namespace of the superblock.
This also means that the keys in the DNS record cache are
thenceforth namespaced, provided network filesystems pass the
appropriate network namespace down into dns_query().
For DNS, AFS and NFS are good, whilst CIFS and Ceph are not. Other
cache keyrings, such as idmapper keyrings, also need to set the
domain tag - for which they need access to the network namespace of
the superblock"
* tag 'keys-namespace-20190627' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
keys: Pass the network namespace into request_key mechanism
keys: Network namespace domain tag
keys: Garbage collect keys for which the domain has been removed
keys: Include target namespace in match criteria
keys: Move the user and user-session keyrings to the user_namespace
keys: Namespace keyring names
keys: Add a 'recurse' flag for keyring searches
keys: Cache the hash value to avoid lots of recalculation
keys: Simplify key description management
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull misc keyring updates from David Howells:
"These are some miscellaneous keyrings fixes and improvements:
- Fix a bunch of warnings from sparse, including missing RCU bits and
kdoc-function argument mismatches
- Implement a keyctl to allow a key to be moved from one keyring to
another, with the option of prohibiting key replacement in the
destination keyring.
- Grant Link permission to possessors of request_key_auth tokens so
that upcall servicing daemons can more easily arrange things such
that only the necessary auth key is passed to the actual service
program, and not all the auth keys a daemon might possesss.
- Improvement in lookup_user_key().
- Implement a keyctl to allow keyrings subsystem capabilities to be
queried.
The keyutils next branch has commits to make available, document and
test the move-key and capabilities code:
https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/keyutils.git/log
They're currently on the 'next' branch"
* tag 'keys-misc-20190619' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
keys: Add capability-checking keyctl function
keys: Reuse keyring_index_key::desc_len in lookup_user_key()
keys: Grant Link permission to possessers of request_key auth keys
keys: Add a keyctl to move a key between keyrings
keys: Hoist locking out of __key_link_begin()
keys: Break bits out of key_unlink()
keys: Change keyring_serialise_link_sem to a mutex
keys: sparse: Fix kdoc mismatches
keys: sparse: Fix incorrect RCU accesses
keys: sparse: Fix key_fs[ug]id_changed()
|
|
Provide a keyctl() operation to grant/remove permissions. The grant
operation, wrapped by libkeyutils, looks like:
int ret = keyctl_grant_permission(key_serial_t key,
enum key_ace_subject_type type,
unsigned int subject,
unsigned int perm);
Where key is the key to be modified, type and subject represent the subject
to which permission is to be granted (or removed) and perm is the set of
permissions to be granted. 0 is returned on success. SET_SECURITY
permission is required for this.
The subject type currently must be KEY_ACE_SUBJ_STANDARD for the moment
(other subject types will come along later).
For subject type KEY_ACE_SUBJ_STANDARD, the following subject values are
available:
KEY_ACE_POSSESSOR The possessor of the key
KEY_ACE_OWNER The owner of the key
KEY_ACE_GROUP The key's group
KEY_ACE_EVERYONE Everyone
perm lists the permissions to be granted:
KEY_ACE_VIEW Can view the key metadata
KEY_ACE_READ Can read the key content
KEY_ACE_WRITE Can update/modify the key content
KEY_ACE_SEARCH Can find the key by searching/requesting
KEY_ACE_LINK Can make a link to the key
KEY_ACE_SET_SECURITY Can set security
KEY_ACE_INVAL Can invalidate
KEY_ACE_REVOKE Can revoke
KEY_ACE_JOIN Can join this keyring
KEY_ACE_CLEAR Can clear this keyring
If an ACE already exists for the subject, then the permissions mask will be
overwritten; if perm is 0, it will be deleted.
Currently, the internal ACL is limited to a maximum of 16 entries.
For example:
int ret = keyctl_grant_permission(key,
KEY_ACE_SUBJ_STANDARD,
KEY_ACE_OWNER,
KEY_ACE_VIEW | KEY_ACE_READ);
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
Replace the uid/gid/perm permissions checking on a key with an ACL to allow
the SETATTR and SEARCH permissions to be split. This will also allow a
greater range of subjects to represented.
============
WHY DO THIS?
============
The problem is that SETATTR and SEARCH cover a slew of actions, not all of
which should be grouped together.
For SETATTR, this includes actions that are about controlling access to a
key:
(1) Changing a key's ownership.
(2) Changing a key's security information.
(3) Setting a keyring's restriction.
And actions that are about managing a key's lifetime:
(4) Setting an expiry time.
(5) Revoking a key.
and (proposed) managing a key as part of a cache:
(6) Invalidating a key.
Managing a key's lifetime doesn't really have anything to do with
controlling access to that key.
Expiry time is awkward since it's more about the lifetime of the content
and so, in some ways goes better with WRITE permission. It can, however,
be set unconditionally by a process with an appropriate authorisation token
for instantiating a key, and can also be set by the key type driver when a
key is instantiated, so lumping it with the access-controlling actions is
probably okay.
As for SEARCH permission, that currently covers:
(1) Finding keys in a keyring tree during a search.
(2) Permitting keyrings to be joined.
(3) Invalidation.
But these don't really belong together either, since these actions really
need to be controlled separately.
Finally, there are number of special cases to do with granting the
administrator special rights to invalidate or clear keys that I would like
to handle with the ACL rather than key flags and special checks.
===============
WHAT IS CHANGED
===============
The SETATTR permission is split to create two new permissions:
(1) SET_SECURITY - which allows the key's owner, group and ACL to be
changed and a restriction to be placed on a keyring.
(2) REVOKE - which allows a key to be revoked.
The SEARCH permission is split to create:
(1) SEARCH - which allows a keyring to be search and a key to be found.
(2) JOIN - which allows a keyring to be joined as a session keyring.
(3) INVAL - which allows a key to be invalidated.
The WRITE permission is also split to create:
(1) WRITE - which allows a key's content to be altered and links to be
added, removed and replaced in a keyring.
(2) CLEAR - which allows a keyring to be cleared completely. This is
split out to make it possible to give just this to an administrator.
(3) REVOKE - see above.
Keys acquire ACLs which consist of a series of ACEs, and all that apply are
unioned together. An ACE specifies a subject, such as:
(*) Possessor - permitted to anyone who 'possesses' a key
(*) Owner - permitted to the key owner
(*) Group - permitted to the key group
(*) Everyone - permitted to everyone
Note that 'Other' has been replaced with 'Everyone' on the assumption that
you wouldn't grant a permit to 'Other' that you wouldn't also grant to
everyone else.
Further subjects may be made available by later patches.
The ACE also specifies a permissions mask. The set of permissions is now:
VIEW Can view the key metadata
READ Can read the key content
WRITE Can update/modify the key content
SEARCH Can find the key by searching/requesting
LINK Can make a link to the key
SET_SECURITY Can change owner, ACL, expiry
INVAL Can invalidate
REVOKE Can revoke
JOIN Can join this keyring
CLEAR Can clear this keyring
The KEYCTL_SETPERM function is then deprecated.
The KEYCTL_SET_TIMEOUT function then is permitted if SET_SECURITY is set,
or if the caller has a valid instantiation auth token.
The KEYCTL_INVALIDATE function then requires INVAL.
The KEYCTL_REVOKE function then requires REVOKE.
The KEYCTL_JOIN_SESSION_KEYRING function then requires JOIN to join an
existing keyring.
The JOIN permission is enabled by default for session keyrings and manually
created keyrings only.
======================
BACKWARD COMPATIBILITY
======================
To maintain backward compatibility, KEYCTL_SETPERM will translate the
permissions mask it is given into a new ACL for a key - unless
KEYCTL_SET_ACL has been called on that key, in which case an error will be
returned.
It will convert possessor, owner, group and other permissions into separate
ACEs, if each portion of the mask is non-zero.
SETATTR permission turns on all of INVAL, REVOKE and SET_SECURITY. WRITE
permission turns on WRITE, REVOKE and, if a keyring, CLEAR. JOIN is turned
on if a keyring is being altered.
The KEYCTL_DESCRIBE function translates the ACL back into a permissions
mask to return depending on possessor, owner, group and everyone ACEs.
It will make the following mappings:
(1) INVAL, JOIN -> SEARCH
(2) SET_SECURITY -> SETATTR
(3) REVOKE -> WRITE if SETATTR isn't already set
(4) CLEAR -> WRITE
Note that the value subsequently returned by KEYCTL_DESCRIBE may not match
the value set with KEYCTL_SETATTR.
=======
TESTING
=======
This passes the keyutils testsuite for all but a couple of tests:
(1) tests/keyctl/dh_compute/badargs: The first wrong-key-type test now
returns EOPNOTSUPP rather than ENOKEY as READ permission isn't removed
if the type doesn't have ->read(). You still can't actually read the
key.
(2) tests/keyctl/permitting/valid: The view-other-permissions test doesn't
work as Other has been replaced with Everyone in the ACL.
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
Create a request_key_net() function and use it to pass the network
namespace domain tag into DNS revolver keys and rxrpc/AFS keys so that keys
for different domains can coexist in the same keyring.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: netdev@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-afs@lists.infradead.org
|
|
Currently a key has a standard matching criteria of { type, description }
and this is used to only allow keys with unique criteria in a keyring.
This means, however, that you cannot have keys with the same type and
description but a different target namespace in the same keyring.
This is a potential problem for a containerised environment where, say, a
container is made up of some parts of its mount space involving netfs
superblocks from two different network namespaces.
This is also a problem for shared system management keyrings such as the
DNS records keyring or the NFS idmapper keyring that might contain keys
from different network namespaces.
Fix this by including a namespace component in a key's matching criteria.
Keyring types are marked to indicate which, if any, namespace is relevant
to keys of that type, and that namespace is set when the key is created
from the current task's namespace set.
The capability bit KEYCTL_CAPS1_NS_KEY_TAG is set if the kernel is
employing this feature.
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
Keyring names are held in a single global list that any process can pick
from by means of keyctl_join_session_keyring (provided the keyring grants
Search permission). This isn't very container friendly, however.
Make the following changes:
(1) Make default session, process and thread keyring names begin with a
'.' instead of '_'.
(2) Keyrings whose names begin with a '.' aren't added to the list. Such
keyrings are system specials.
(3) Replace the global list with per-user_namespace lists. A keyring adds
its name to the list for the user_namespace that it is currently in.
(4) When a user_namespace is deleted, it just removes itself from the
keyring name list.
The global keyring_name_lock is retained for accessing the name lists.
This allows (4) to work.
This can be tested by:
# keyctl newring foo @s
995906392
# unshare -U
$ keyctl show
...
995906392 --alswrv 65534 65534 \_ keyring: foo
...
$ keyctl session foo
Joined session keyring: 935622349
As can be seen, a new session keyring was created.
The capability bit KEYCTL_CAPS1_NS_KEYRING_NAME is set if the kernel is
employing this feature.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Eric W. Biederman <ebiederm@xmission.com>
|
|
Add a 'recurse' flag for keyring searches so that the flag can be omitted
and recursion disabled, thereby allowing just the nominated keyring to be
searched and none of the children.
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
Add a keyctl function that requests a set of capability bits to find out
what features are supported.
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
Add a keyctl to atomically move a link to a key from one keyring to
another. The key must exist in "from" keyring and a flag can be given to
cause the operation to fail if there's a matching key already in the "to"
keyring.
This can be done with:
keyctl(KEYCTL_MOVE,
key_serial_t key,
key_serial_t from_keyring,
key_serial_t to_keyring,
unsigned int flags);
The key being moved must grant Link permission and both keyrings must grant
Write permission.
flags should be 0 or KEYCTL_MOVE_EXCL, with the latter preventing
displacement of a matching key from the "to" keyring.
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Fix a pair of accesses that should be using RCU protection.
rcu_dereference_protected() is needed to access task_struct::real_parent.
current_cred() should be used to access current->cred.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
- Extend LSM stacking to allow sharing of cred, file, ipc, inode, and
task blobs. This paves the way for more full-featured LSMs to be
merged, and is specifically aimed at LandLock and SARA LSMs. This
work is from Casey and Kees.
- There's a new LSM from Micah Morton: "SafeSetID gates the setid
family of syscalls to restrict UID/GID tran |
