Once a key's reference count has been reduced to 0, the garbage collector
thread may destroy it at any time and so key_put() is not allowed to touch
the key after that point. The most key_put() is normally allowed to do is
to touch key_gc_work as that's a static global variable.
However, in an effort to speed up the reclamation of quota, this is now
done in key_put() once the key's usage is reduced to 0 - but now the code
is looking at the key after the deadline, which is forbidden.
Fix this by using a flag to indicate that a key can be gc'd now rather than
looking at the key's refcount in the garbage collector.
Fixes: 9578e327b2 ("keys: update key quotas in key_put()")
Reported-by: syzbot+6105ffc1ded71d194d6d@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/673b6aec.050a0220.87769.004a.GAE@google.com/
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: syzbot+6105ffc1ded71d194d6d@syzkaller.appspotmail.com
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Delaying key quotas update when key's refcount reaches 0 in key_put() has
been causing some issues in fscrypt testing, specifically in fstest
generic/581. This commit fixes this test flakiness by dealing with the
quotas immediately, and leaving all the other clean-ups to the key garbage
collector.
This is done by moving the updates to the qnkeys and qnbytes fields in
struct key_user from key_gc_unused_keys() into key_put(). Unfortunately,
this also means that we need to switch to the irq-version of the spinlock
that protects these fields and use spin_lock_{irqsave,irqrestore} in all
the code that touches these fields.
Signed-off-by: Luis Henriques <lhenriques@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@kernel.org>
If a key has an expiration time, then when that time passes, the key is
left around for a certain amount of time before being collected (5 mins by
default) so that EKEYEXPIRED can be returned instead of ENOKEY. This is a
problem for DNS keys because we want to redo the DNS lookup immediately at
that point.
Fix this by allowing key types to be marked such that keys of that type
don't have this extra period, but are reclaimed as soon as they expire and
turn this on for dns_resolver-type keys. To make this easier to handle,
key->expiry is changed to be permanent if TIME64_MAX rather than 0.
Furthermore, give such new-style negative DNS results a 1s default expiry
if no other expiry time is set rather than allowing it to stick around
indefinitely. This shouldn't be zero as ls will follow a failing stat call
immediately with a second with AT_SYMLINK_NOFOLLOW added.
Fixes: 1a4240f476 ("DNS: Separate out CIFS DNS Resolver code")
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Markus Suvanto <markus.suvanto@gmail.com>
cc: Wang Lei <wang840925@gmail.com>
cc: Jeff Layton <jlayton@redhat.com>
cc: Steve French <smfrench@gmail.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jarkko Sakkinen <jarkko@kernel.org>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: keyrings@vger.kernel.org
cc: netdev@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>
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
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
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>
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>
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 licence as published by
the free software foundation either version 2 of the licence 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 114 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends. That changed
when we forked out support for the latter into the export.h file.
This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.
The advantage in removing such instances is that module.h itself
sources about 15 other headers; adding significantly to what we feed
cpp, and it can obscure what headers we are effectively using.
Since module.h might have been the implicit source for init.h
(for __init) and for export.h (for EXPORT_SYMBOL) we consider each
instance for the presence of either and replace as needed.
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-security-module@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
Cc: keyrings@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
Pull timer updates from Thomas Gleixner:
- The final conversion of timer wheel timers to timer_setup().
A few manual conversions and a large coccinelle assisted sweep and
the removal of the old initialization mechanisms and the related
code.
- Remove the now unused VSYSCALL update code
- Fix permissions of /proc/timer_list. I still need to get rid of that
file completely
- Rename a misnomed clocksource function and remove a stale declaration
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
m68k/macboing: Fix missed timer callback assignment
treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE casts
timer: Remove redundant __setup_timer*() macros
timer: Pass function down to initialization routines
timer: Remove unused data arguments from macros
timer: Switch callback prototype to take struct timer_list * argument
timer: Pass timer_list pointer to callbacks unconditionally
Coccinelle: Remove setup_timer.cocci
timer: Remove setup_*timer() interface
timer: Remove init_timer() interface
treewide: setup_timer() -> timer_setup() (2 field)
treewide: setup_timer() -> timer_setup()
treewide: init_timer() -> setup_timer()
treewide: Switch DEFINE_TIMER callbacks to struct timer_list *
s390: cmm: Convert timers to use timer_setup()
lightnvm: Convert timers to use timer_setup()
drivers/net: cris: Convert timers to use timer_setup()
drm/vc4: Convert timers to use timer_setup()
block/laptop_mode: Convert timers to use timer_setup()
net/atm/mpc: Avoid open-coded assignment of timer callback function
...
This changes all DEFINE_TIMER() callbacks to use a struct timer_list
pointer instead of unsigned long. Since the data argument has already been
removed, none of these callbacks are using their argument currently, so
this renames the argument to "unused".
Done using the following semantic patch:
@match_define_timer@
declarer name DEFINE_TIMER;
identifier _timer, _callback;
@@
DEFINE_TIMER(_timer, _callback);
@change_callback depends on match_define_timer@
identifier match_define_timer._callback;
type _origtype;
identifier _origarg;
@@
void
-_callback(_origtype _origarg)
+_callback(struct timer_list *unused)
{ ... }
Signed-off-by: Kees Cook <keescook@chromium.org>
The 'struct key' will use 'time_t' which we try to remove in the
kernel, since 'time_t' is not year 2038 safe on 32bit systems.
Also the 'struct keyring_search_context' will use 'timespec' type
to record current time, which is also not year 2038 safe on 32bit
systems.
Thus this patch replaces 'time_t' with 'time64_t' which is year 2038
safe for 'struct key', and replace 'timespec' with 'time64_t' for the
'struct keyring_search_context', since we only look at the the seconds
part of 'timespec' variable. Moreover we also change the codes where
using the 'time_t' and 'timespec', and we can get current time by
ktime_get_real_seconds() instead of current_kernel_time(), and use
'TIME64_MAX' macro to initialize the 'time64_t' type variable.
Especially in proc.c file, we have replaced 'unsigned long' and 'timespec'
type with 'u64' and 'time64_t' type to save the timeout value, which means
user will get one 'u64' type timeout value by issuing proc_keys_show()
function.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Pull timer updates from Thomas Gleixner:
"Yet another big pile of changes:
- More year 2038 work from Arnd slowly reaching the point where we
need to think about the syscalls themself.
- A new timer function which allows to conditionally (re)arm a timer
only when it's either not running or the new expiry time is sooner
than the armed expiry time. This allows to use a single timer for
multiple timeout requirements w/o caring about the first expiry
time at the call site.
- A new NMI safe accessor to clock real time for the printk timestamp
work. Can be used by tracing, perf as well if required.
- A large number of timer setup conversions from Kees which got
collected here because either maintainers requested so or they
simply got ignored. As Kees pointed out already there are a few
trivial merge conflicts and some redundant commits which was
unavoidable due to the size of this conversion effort.
- Avoid a redundant iteration in the timer wheel softirq processing.
- Provide a mechanism to treat RTC implementations depending on their
hardware properties, i.e. don't inflict the write at the 0.5
seconds boundary which originates from the PC CMOS RTC to all RTCs.
No functional change as drivers need to be updated separately.
- The usual small updates to core code clocksource drivers. Nothing
really exciting"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (111 commits)
timers: Add a function to start/reduce a timer
pstore: Use ktime_get_real_fast_ns() instead of __getnstimeofday()
timer: Prepare to change all DEFINE_TIMER() callbacks
netfilter: ipvs: Convert timers to use timer_setup()
scsi: qla2xxx: Convert timers to use timer_setup()
block/aoe: discover_timer: Convert timers to use timer_setup()
ide: Convert timers to use timer_setup()
drbd: Convert timers to use timer_setup()
mailbox: Convert timers to use timer_setup()
crypto: Convert timers to use timer_setup()
drivers/pcmcia: omap1: Fix error in automated timer conversion
ARM: footbridge: Fix typo in timer conversion
drivers/sgi-xp: Convert timers to use timer_setup()
drivers/pcmcia: Convert timers to use timer_setup()
drivers/memstick: Convert timers to use timer_setup()
drivers/macintosh: Convert timers to use timer_setup()
hwrng/xgene-rng: Convert timers to use timer_setup()
auxdisplay: Convert timers to use timer_setup()
sparc/led: Convert timers to use timer_setup()
mips: ip22/32: Convert timers to use timer_setup()
...
Consolidate KEY_FLAG_INSTANTIATED, KEY_FLAG_NEGATIVE and the rejection
error into one field such that:
(1) The instantiation state can be modified/read atomically.
(2) The error can be accessed atomically with the state.
(3) The error isn't stored unioned with the payload pointers.
This deals with the problem that the state is spread over three different
objects (two bits and a separate variable) and reading or updating them
atomically isn't practical, given that not only can uninstantiated keys
change into instantiated or rejected keys, but rejected keys can also turn
into instantiated keys - and someone accessing the key might not be using
any locking.
The main side effect of this problem is that what was held in the payload
may change, depending on the state. For instance, you might observe the
key to be in the rejected state. You then read the cached error, but if
the key semaphore wasn't locked, the key might've become instantiated
between the two reads - and you might now have something in hand that isn't
actually an error code.
The state is now KEY_IS_UNINSTANTIATED, KEY_IS_POSITIVE or a negative error
code if the key is negatively instantiated. The key_is_instantiated()
function is replaced with key_is_positive() to avoid confusion as negative
keys are also 'instantiated'.
Additionally, barriering is included:
(1) Order payload-set before state-set during instantiation.
(2) Order state-read before payload-read when using the key.
Further separate barriering is necessary if RCU is being used to access the
payload content after reading the payload pointers.
Fixes: 146aa8b145 ("KEYS: Merge the type-specific data with the payload data")
Cc: stable@vger.kernel.org # v4.4+
Reported-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
While a 'struct key' itself normally does not contain sensitive
information, Documentation/security/keys.txt actually encourages this:
"Having a payload is not required; and the payload can, in fact,
just be a value stored in the struct key itself."
In case someone has taken this advice, or will take this advice in the
future, zero the key structure before freeing it. We might as well, and
as a bonus this could make it a bit more difficult for an adversary to
determine which keys have recently been in use.
This is safe because the key_jar cache does not use a constructor.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Pull security subsystem updates from James Morris:
"Highlights:
IMA:
- provide ">" and "<" operators for fowner/uid/euid rules
KEYS:
- add a system blacklist keyring
- add KEYCTL_RESTRICT_KEYRING, exposes keyring link restriction
functionality to userland via keyctl()
LSM:
- harden LSM API with __ro_after_init
- add prlmit security hook, implement for SELinux
- revive security_task_alloc hook
TPM:
- implement contextual TPM command 'spaces'"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (98 commits)
tpm: Fix reference count to main device
tpm_tis: convert to using locality callbacks
tpm: fix handling of the TPM 2.0 event logs
tpm_crb: remove a cruft constant
keys: select CONFIG_CRYPTO when selecting DH / KDF
apparmor: Make path_max parameter readonly
apparmor: fix parameters so that the permission test is bypassed at boot
apparmor: fix invalid reference to index variable of iterator line 836
apparmor: use SHASH_DESC_ON_STACK
security/apparmor/lsm.c: set debug messages
apparmor: fix boolreturn.cocci warnings
Smack: Use GFP_KERNEL for smk_netlbl_mls().
smack: fix double free in smack_parse_opts_str()
KEYS: add SP800-56A KDF support for DH
KEYS: Keyring asymmetric key restrict method with chaining
KEYS: Restrict asymmetric key linkage using a specific keychain
KEYS: Add a lookup_restriction function for the asymmetric key type
KEYS: Add KEYCTL_RESTRICT_KEYRING
KEYS: Consistent ordering for __key_link_begin and restrict check
KEYS: Add an optional lookup_restriction hook to key_type
...
This fixes CVE-2017-6951.
Userspace should not be able to do things with the "dead" key type as it
doesn't have some of the helper functions set upon it that the kernel
needs. Attempting to use it may cause the kernel to crash.
Fix this by changing the name of the type to ".dead" so that it's rejected
up front on userspace syscalls by key_get_type_from_user().
Though this doesn't seem to affect recent kernels, it does affect older
ones, certainly those prior to:
commit c06cfb08b8
Author: David Howells <dhowells@redhat.com>
Date: Tue Sep 16 17:36:06 2014 +0100
KEYS: Remove key_type::match in favour of overriding default by match_preparse
which went in before 3.18-rc1.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: stable@vger.kernel.org
Replace struct key's restrict_link function pointer with a pointer to
the new struct key_restriction. The structure contains pointers to the
restriction function as well as relevant data for evaluating the
restriction.
The garbage collector checks restrict_link->keytype when key types are
unregistered. Restrictions involving a removed key type are converted
to use restrict_link_reject so that restrictions cannot be removed by
unregistering key types.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
The following sequence of commands:
i=`keyctl add user a a @s`
keyctl request2 keyring foo bar @t
keyctl unlink $i @s
tries to invoke an upcall to instantiate a keyring if one doesn't already
exist by that name within the user's keyring set. However, if the upcall
fails, the code sets keyring->type_data.reject_error to -ENOKEY or some
other error code. When the key is garbage collected, the key destroy
function is called unconditionally and keyring_destroy() uses list_empty()
on keyring->type_data.link - which is in a union with reject_error.
Subsequently, the kernel tries to unlink the keyring from the keyring names
list - which oopses like this:
BUG: unable to handle kernel paging request at 00000000ffffff8a
IP: [<ffffffff8126e051>] keyring_destroy+0x3d/0x88
...
Workqueue: events key_garbage_collector
...
RIP: 0010:[<ffffffff8126e051>] keyring_destroy+0x3d/0x88
RSP: 0018:ffff88003e2f3d30 EFLAGS: 00010203
RAX: 00000000ffffff82 RBX: ffff88003bf1a900 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 000000003bfc6901 RDI: ffffffff81a73a40
RBP: ffff88003e2f3d38 R08: 0000000000000152 R09: 0000000000000000
R10: ffff88003e2f3c18 R11: 000000000000865b R12: ffff88003bf1a900
R13: 0000000000000000 R14: ffff88003bf1a908 R15: ffff88003e2f4000
...
CR2: 00000000ffffff8a CR3: 000000003e3ec000 CR4: 00000000000006f0
...
Call Trace:
[<ffffffff8126c756>] key_gc_unused_keys.constprop.1+0x5d/0x10f
[<ffffffff8126ca71>] key_garbage_collector+0x1fa/0x351
[<ffffffff8105ec9b>] process_one_work+0x28e/0x547
[<ffffffff8105fd17>] worker_thread+0x26e/0x361
[<ffffffff8105faa9>] ? rescuer_thread+0x2a8/0x2a8
[<ffffffff810648ad>] kthread+0xf3/0xfb
[<ffffffff810647ba>] ? kthread_create_on_node+0x1c2/0x1c2
[<ffffffff815f2ccf>] ret_from_fork+0x3f/0x70
[<ffffffff810647ba>] ? kthread_create_on_node+0x1c2/0x1c2
Note the value in RAX. This is a 32-bit representation of -ENOKEY.
The solution is to only call ->destroy() if the key was successfully
instantiated.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
There appears to be a race between:
(1) key_gc_unused_keys() which frees key->security and then calls
keyring_destroy() to unlink the name from the name list
(2) find_keyring_by_name() which calls key_permission(), thus accessing
key->security, on a key before checking to see whether the key usage is 0
(ie. the key is dead and might be cleaned up).
Fix this by calling ->destroy() before cleaning up the core key data -
including key->security.
Reported-by: Petr Matousek <pmatouse@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Herbert XuandLinus Torvalds
David HowellsandJarkko Sakkinen
Luis HenriquesandJarkko Sakkinen
Thomas GleixnerandGreg Kroah-Hartman
Paul GortmakerandJames Morris
Kees Cook
Baolin WangandDavid Howells
Eric BiggersandJames Morris
Mat Martineau
Elena ReshetovaandJames Morris