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If a request_key authentication token key gets revoked, there's a window in
which request_key_auth_describe() can see it with a NULL payload - but it
makes no check for this and something like the following oops may occur:
BUG: Kernel NULL pointer dereference at 0x00000038
Faulting instruction address: 0xc0000000004ddf30
Oops: Kernel access of bad area, sig: 11 [#1]
...
NIP [...] request_key_auth_describe+0x90/0xd0
LR [...] request_key_auth_describe+0x54/0xd0
Call Trace:
[...] request_key_auth_describe+0x54/0xd0 (unreliable)
[...] proc_keys_show+0x308/0x4c0
[...] seq_read+0x3d0/0x540
[...] proc_reg_read+0x90/0x110
[...] __vfs_read+0x3c/0x70
[...] vfs_read+0xb4/0x1b0
[...] ksys_read+0x7c/0x130
[...] system_call+0x5c/0x70
Fix this by checking for a NULL pointer when describing such a key.
Also make the read routine check for a NULL pointer to be on the safe side.
[DH: Modified to not take already-held rcu lock and modified to also check
in the read routine]
Fixes: 04c567d9313e ("[PATCH] Keys: Fix race between two instantiators of a key")
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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If check_cached_key() returns a non-NULL value, we still need to call
key_type::match_free() to undo key_type::match_preparse().
Fixes: 7743c48e54ee ("keys: Cache result of request_key*() temporarily in task_struct")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Commit c78719203fc6 ("KEYS: trusted: allow trusted.ko to initialize w/o a
TPM") allows the trusted module to be loaded even if a TPM is not found, to
avoid module dependency problems.
However, trusted module initialization can still fail if the TPM is
inactive or deactivated. tpm_get_random() returns an error.
This patch removes the call to tpm_get_random() and instead extends the PCR
specified by the user with zeros. The security of this alternative is
equivalent to the previous one, as either option prevents with a PCR update
unsealing and misuse of sealed data by a user space process.
Even if a PCR is extended with zeros, instead of random data, it is still
computationally infeasible to find a value as input for a new PCR extend
operation, to obtain again the PCR value that would allow unsealing.
Cc: stable@vger.kernel.org
Fixes: 240730437deb ("KEYS: trusted: explicitly use tpm_chip structure...")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
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In the sysctl code the proc_dointvec_minmax() function is often used to
validate the user supplied value between an allowed range. This
function uses the extra1 and extra2 members from struct ctl_table as
minimum and maximum allowed value.
On sysctl handler declaration, in every source file there are some
readonly variables containing just an integer which address is assigned
to the extra1 and extra2 members, so the sysctl range is enforced.
The special values 0, 1 and INT_MAX are very often used as range
boundary, leading duplication of variables like zero=0, one=1,
int_max=INT_MAX in different source files:
$ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l
248
Add a const int array containing the most commonly used values, some
macros to refer more easily to the correct array member, and use them
instead of creating a local one for every object file.
This is the bloat-o-meter output comparing the old and new binary
compiled with the default Fedora config:
# scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o
add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164)
Data old new delta
sysctl_vals - 12 +12
__kstrtab_sysctl_vals - 12 +12
max 14 10 -4
int_max 16 - -16
one 68 - -68
zero 128 28 -100
Total: Before=20583249, After=20583085, chg -0.00%
[mcroce@redhat.com: tipc: remove two unused variables]
Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com
[akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c]
[arnd@arndb.de: proc/sysctl: make firmware loader table conditional]
Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de
[akpm@linux-foundation.org: fix fs/eventpoll.c]
Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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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>
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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
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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
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git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull request_key improvements from David Howells:
"These are all request_key()-related, including a fix and some improvements:
- Fix the lack of a Link permission check on a key found by
request_key(), thereby enabling request_key() to link keys that
don't grant this permission to the target keyring (which must still
grant Write permission).
Note that the key must be in the caller's keyrings already to be
found.
- Invalidate used request_key authentication keys rather than
revoking them, so that they get cleaned up immediately rather than
hanging around till the expiry time is passed.
- Move the RCU locks outwards from the keyring search functions so
that a request_key_rcu() can be provided. This can be called in RCU
mode, so it can't sleep and can't upcall - but it can be called
from LOOKUP_RCU pathwalk mode.
- Cache the latest positive result of request_key*() temporarily in
task_struct so that filesystems that make a lot of request_key()
calls during pathwalk can take advantage of it to avoid having to
redo the searching. This requires CONFIG_KEYS_REQUEST_CACHE=y.
It is assumed that the key just found is likely to be used multiple
times in each step in an RCU pathwalk, and is likely to be reused
for the next step too.
Note that the cleanup of the cache is done on TIF_NOTIFY_RESUME,
just before userspace resumes, and on exit"
* tag 'keys-request-20190626' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
keys: Kill off request_key_async{,_with_auxdata}
keys: Cache result of request_key*() temporarily in task_struct
keys: Provide request_key_rcu()
keys: Move the RCU locks outwards from the keyring search functions
keys: Invalidate used request_key authentication keys
keys: Fix request_key() lack of Link perm check on found key
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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()
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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>
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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>
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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
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Create key domain tags for network namespaces and make it possible to
automatically tag keys that are used by networked services (e.g. AF_RXRPC,
AFS, DNS) with the default network namespace if not set by the caller.
This allows keys with the same description but in different namespaces to
coexist within a 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
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If a key operation domain (such as a network namespace) has been removed
then attempt to garbage collect all the keys that use it.
Signed-off-by: David Howells <dhowells@redhat.com>
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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>
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Move the user and user-session keyrings to the user_namespace struct rather
than pinning them from the user_struct struct. This prevents these
keyrings from propagating across user-namespaces boundaries with regard to
the KEY_SPEC_* flags, thereby making them more useful in a containerised
environment.
The issue is that a single user_struct may be represent UIDs in several
different namespaces.
The way the patch does this is by attaching a 'register keyring' in each
user_namespace and then sticking the user and user-session keyrings into
that. It can then be searched to retrieve them.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jann Horn <jannh@google.com>
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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>
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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>
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Cache the hash of the key's type and description in the index key so that
we're not recalculating it every time we look at a key during a search.
The hash function does a bunch of multiplications, so evading those is
probably worthwhile - especially as this is done for every key examined
during a search.
This also allows the methods used by assoc_array to get chunks of index-key
to be simplified.
Signed-off-by: David Howells <dhowells@redhat.com>
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Simplify key description management by cramming the word containing the
length with the first few chars of the description also. This simplifies
the code that generates the index-key used by assoc_array. It should speed
up key searching a bit too.
Signed-off-by: David Howells <dhowells@redhat.com>
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Kill off request_key_async{,_with_auxdata}() as they're not currently used.
Signed-off-by: David Howells <dhowells@redhat.com>
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If a filesystem uses keys to hold authentication tokens, then it needs a
token for each VFS operation that might perform an authentication check -
either by passing it to the server, or using to perform a check based on
authentication data cached locally.
For open files this isn't a problem, since the key should be cached in the
file struct since it represents the subject performing operations on that
file descriptor.
During pathwalk, however, there isn't anywhere to cache the key, except
perhaps in the nameidata struct - but that isn't exposed to the
filesystems. Further, a pathwalk can incur a lot of operations, calling
one or more of the following, for instance:
->lookup()
->permission()
->d_revalidate()
->d_automount()
->get_acl()
->getxattr()
on each dentry/inode it encounters - and each one may need to call
request_key(). And then, at the end of pathwalk, it will call the actual
operation:
->mkdir()
->mknod()
->getattr()
->open()
...
which may need to go and get the token again.
However, it is very likely that all of the operations on a single
dentry/inode - and quite possibly a sequence of them - will all want to use
the same authentication token, which suggests that caching it would be a
good idea.
To this end:
(1) Make it so that a positive result of request_key() and co. that didn't
require upcalling to userspace is cached temporarily in task_struct.
(2) The cache is 1 deep, so a new result displaces the old one.
(3) The key is released by exit and by notify-resume.
(4) The cache is cleared in a newly forked process.
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
Provide a request_key_rcu() function that can be used to request a key
under RCU conditions. It can only search and check permissions; it cannot
allocate a new key, upcall or wait for an upcall to complete. It may
return a partially constructed key.
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
Move the RCU locks outwards from the keyring search functions so that it
will become possible to provide an RCU-capable partial request_key()
function in a later commit.
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
Invalidate used request_key authentication keys rather than revoking them
so that they get cleaned up immediately rather than potentially hanging
around. There doesn't seem any need to keep the revoked keys around.
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
The request_key() syscall allows a process to gain access to the 'possessor'
permits of any key that grants it Search permission by virtue of request_key()
not checking whether a key it finds grants Link permission to the caller.
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>
|
|
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 version 2 of the license
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 315 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
When lookup_user_key() checks whether the key is possessed, it should
use the key's existing index_key including the 'desc_len' field, rather
than recomputing the 'desc_len'. This doesn't change the behavior; this
way is just simpler and faster.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
|
|
Grant Link permission to the possessers of request_key authentication keys,
thereby allowing a daemon that is servicing upcalls to arrange things such
that only the necessary auth key is passed to the actual service program
and not all the daemon's pending auth keys.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.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>
|
|
Hoist the locking of out of __key_link_begin() and into its callers. This
is necessary to allow the upcoming key_move() operation to correctly order
taking of the source keyring semaphore, the destination keyring semaphore
and the keyring serialisation lock.
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>
|
|
Break bits out of key_unlink() into helper functions so that they can be
used in implementing key_move().
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
Change keyring_serialise_link_sem to a mutex as it's only ever
write-locked.
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
Fix some kdoc argument description mismatches reported by sparse and give
keyring_restrict() a description.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
cc: Mat Martineau <mathew.j.martineau@linux.intel.com>
|
|
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>
|
|
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>
|
|
Sparse warnings are incurred by key_fs[ug]id_changed() due to unprotected
accesses of tsk->cred, which is marked __rcu.
Fix this by passing the new cred struct to these functions from
commit_creds() rather than the task pointer.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
|
|
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
"Just a few bugfixes and documentation updates"
* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
seccomp: fix up grammar in comment
Revert "security: inode: fix a missing check for securityfs_create_file"
Yama: mark function as static
security: inode: fix a missing check for securityfs_create_file
keys: safe concurrent user->{session,uid}_keyring access
security: don't use RCU accessors for cred->session_keyring
Yama: mark local symbols as static
LSM: lsm_hooks.h: fix documentation format
LSM: fix documentation for the shm_* hooks
LSM: fix documentation for the sem_* hooks
LSM: fix documentation for the msg_queue_* hooks
LSM: fix documentation for the audit_* hooks
LSM: fix documentation for the path_chmod hook
LSM: fix documentation for the socket_getpeersec_dgram hook
LSM: fix documentation for the task_setscheduler hook
LSM: fix documentation for the socket_post_create hook
LSM: fix documentation for the syslog hook
LSM: fix documentation for sb_copy_data hook
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|
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto update from Herbert Xu:
"API:
- Add support for AEAD in simd
- Add fuzz testing to testmgr
- Add panic_on_fail module parameter to testmgr
- Use per-CPU struct instead multiple variables in scompress
- Change verify API for akcipher
Algorithms:
- Convert x86 AEAD algorithms over to simd
- Forbid 2-key 3DES in FIPS mode
- Add EC-RDSA (GOST 34.10) algorithm
Drivers:
- Set output IV with ctr-aes in crypto4xx
- Set output IV in rockchip
- Fix potential length overflow with hashing in sun4i-ss
- Fix computation error with ctr in vmx
- Add SM4 protected keys support in ccree
- Remove long-broken mxc-scc driver
- Add rfc4106(gcm(aes)) cipher support in cavium/nitrox"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (179 commits)
crypto: ccree - use a proper le32 type for le32 val
crypto: ccree - remove set but not used variable 'du_size'
crypto: ccree - Make cc_sec_disable static
crypto: ccree - fix spelling mistake "protedcted" -> "protected"
crypto: caam/qi2 - generate hash keys in-place
crypto: caam/qi2 - fix DMA mapping of stack memory
crypto: caam/qi2 - fix zero-length buffer DMA mapping
crypto: stm32/cryp - update to return iv_out
crypto: stm32/cryp - remove request mutex protection
crypto: stm32/cryp - add weak key check for DES
crypto: atmel - remove set but not used variable 'alg_name'
crypto: picoxcell - Use dev_get_drvdata()
crypto: crypto4xx - get rid of redundant using_sd variable
crypto: crypto4xx - use sync skcipher for fallback
crypto: crypto4xx - fix cfb and ofb "overran dst buffer" issues
crypto: crypto4xx - fix ctr-aes missing output IV
crypto: ecrdsa - select ASN1 and OID_REGISTRY for EC-RDSA
crypto: ux500 - use ccflags-y instead of CFLAGS_<basename>.o
crypto: ccree - handle tee fips error during power management resume
crypto: ccree - add function to handle cryptocell tee fips error
...
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|
The flags field in 'struct shash_desc' never actually does anything.
The only ostensibly supported flag is CRYPTO_TFM_REQ_MAY_SLEEP.
However, no shash algorithm ever sleeps, making this flag a no-op.
With this being the case, inevitably some users who can't sleep wrongly
pass MAY_SLEEP. These would all need to be fixed if any shash algorithm
actually started sleeping. For example, the shash_ahash_*() functions,
which wrap a shash algorithm with the ahash API, pass through MAY_SLEEP
from the ahash API to the shash API. However, the shash functions are
called under kmap_atomic(), so actually they're assumed to never sleep.
Even if it turns out that some users do need preemption points while
hashing large buffers, we could easily provide a helper function
crypto_shash_update_large() which divides the data into smaller chunks
and calls crypto_shash_update() and cond_resched() for each chunk. It's
not necessary to have a flag in 'struct shash_desc', nor is it necessary
to make individual shash algorithms aware of this at all.
Therefore, remove shash_desc::flags, and document that the
crypto_shash_*() functions can be called from any context.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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The current code can perform concurrent updates and reads on
user->session_keyring and user->uid_keyring. Add a comment to
struct user_struct to document the nontrivial locking semantics, and use
READ_ONCE() for unlocked readers and smp_store_release() for writers to
prevent memory ordering issues.
Fixes: 69664cf16af4 ("keys: don't generate user and user session keyrings unless they're accessed")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
|
|
sparse complains that a bunch of places in kernel/cred.c access
cred->session_keyring without the RCU helpers required by the __rcu
annotation.
cred->session_keyring is written in the following places:
- prepare_kernel_cred() [in a new cred struct]
- keyctl_session_to_parent() [in a new cred struct]
- prepare_creds [in a new cred struct, via memcpy]
- install_session_keyring_to_cred()
- from install_session_keyring() on new creds
- from join_session_keyring() on new creds [twice]
- from umh_keys_init()
- from call_usermodehelper_exec_async() on new creds
All of these writes are before the creds are committed; therefore,
cred->session_keyring doesn't need RCU protection.
Remove the __rcu annotation and fix up all existing users that use __rcu.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
|
|
Fixes the warning reported by Clang:
security/keys/trusted.c:146:17: warning: passing an object that
undergoes default
argument promotion to 'va_start' has undefined behavior [-Wvarargs]
va_start(argp, h3);
^
security/keys/trusted.c:126:37: note: parameter of type 'unsigned
char' is declared here
unsigned char *h2, unsigned char h3, ...)
^
Specifically, it seems that both the C90 (4.8.1.1) and C11 (7.16.1.4)
standards explicitly call this out as undefined behavior:
The parameter parmN is the identifier of the rightmost parameter in
the variable parameter list in the function definition (the one just
before the ...). If the parameter parmN is declared with ... or with a
type that is not compatible with the type that results after
application of the default argument promotions, the behavior is
undefined.
Link: https://github.com/ClangBuiltLinux/linux/issues/41
Link: https://www.eskimo.com/~scs/cclass/int/sx11c.html
Suggested-by: David Laight <David.Laight@aculab.com>
Suggested-by: Denis Kenzior <denkenz@gmail.com>
Suggested-by: James Bottomley <jejb@linux.vnet.ibm.com>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
|
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Allow trusted.ko to initialize w/o a TPM. This commit also adds checks
to the exported functions to fail when a TPM is not available.
Fixes: 240730437deb ("KEYS: trusted: explicitly use tpm_chip structure...")
Cc: James Morris <jmorris@namei.org>
Reported-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull tpm updates from James Morris:
- Clean up the transmission flow
Cleaned up the whole transmission flow. Locking of the chip is now
done in the level of tpm_try_get_ops() and tpm_put_ops() instead
taking the chip lock inside tpm_transmit(). The nested calls inside
tpm_transmit(), used with the resource manager, have been refactored
out.
Should make easier to perform more complex transactions with the TPM
without making the subsystem a bigger mess (e.g. encrypted channel
patches by James Bottomley).
- PPI 1.3 support
TPM PPI 1.3 introduces an additional optional command parameter that
may be needed for some commands. Display the parameter if the command
requires such a parameter. Only command 23 (SetPCRBanks) needs one.
The PPI request file will show output like this then:
# echo "23 16" > request
# cat request
23 16
# echo "5" > request
# cat request
5
- Extend all PCR banks in IMA
Instead of static PCR banks array, the array of available PCR banks
is now allocated dynamically. The digests sizes are determined
dynamically using a probe PCR read without relying crypto's static
list of hash algorithms.
This should finally make sealing of measurements in IMA safe and
secure.
- TPM 2.0 selftests
Added a test suite to tools/testing/selftests/tpm2 previously outside
of the kernel tree: https://github.com/jsakkine-intel/tpm2-scripts
* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (37 commits)
tpm/ppi: Enable submission of optional command parameter for PPI 1.3
tpm/ppi: Possibly show command parameter if TPM PPI 1.3 is used
tpm/ppi: Display up to 101 operations as define for version 1.3
tpm/ppi: rename TPM_PPI_REVISION_ID to TPM_PPI_REVISION_ID_1
tpm/ppi: pass function revision ID to tpm_eval_dsm()
tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()
KEYS: trusted: explicitly use tpm_chip structure from tpm_default_chip()
tpm: move tpm_chip definition to include/linux/tpm.h
tpm: retrieve digest size of unknown algorithms with PCR read
tpm: rename and export tpm2_digest and tpm2_algorithms
tpm: dynamically allocate the allocated_banks array
tpm: remove @flags from tpm_transmit()
tpm: take TPM chip power gating out of tpm_transmit()
tpm: introduce tpm_chip_start() and tpm_chip_stop()
tpm: remove TPM_TRANSMIT_UNLOCKED flag
tpm: use tpm_try_get_ops() in tpm-sysfs.c.
tpm: remove @space from tpm_transmit()
tpm: move TPM space code out of tpm_transmit()
tpm: move tpm_validate_commmand() to tpm2-space.c
tpm: clean up tpm_try_transmit() error handling flow
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull integrity updates from James Morris:
"Mimi Zohar says:
'Linux 5.0 introduced the platform keyring to allow verifying the IMA
kexec kernel image signature using the pre-boot keys. This pull
request similarly makes keys on the platform keyring accessible for
verifying the PE kernel image signature.
Also included in this pull request is a new IMA hook that tags tmp
files, in policy, indicating the file hash needs to be calculated.
The remaining patches are cleanup'"
* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
evm: Use defined constant for UUID representation
ima: define ima_post_create_tmpfile() hook and add missing call
evm: remove set but not used variable 'xattr'
encrypted-keys: fix Opt_err/Opt_error = -1
kexec, KEYS: Make use of platform keyring for signature verify
integrity, KEYS: add a reference to platform keyring
|
|
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 transitions from a given
UID/GID to only those approved by a system-wide whitelist." This
feature is currently shipping in ChromeOS.
* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (62 commits)
keys: fix missing __user in KEYCTL_PKEY_QUERY
LSM: Update list of SECURITYFS users in Kconfig
LSM: Ignore "security=" when "lsm=" is specified
LSM: Update function documentation for cap_capable
security: mark expected switch fall-throughs and add a missing break
tomoyo: Bump version.
LSM: fix return value check in safesetid_init_securityfs()
LSM: SafeSetID: add selftest
LSM: SafeSetID: remove unused include
LSM: SafeSetID: 'depend' on CONFIG_SECURITY
LSM: Add 'name' field for SafeSetID in DEFINE_LSM
LSM: add SafeSetID module that gates setid calls
LSM: add SafeSetID module that gates setid calls
tomoyo: Allow multiple use_group lines.
tomoyo: Coding style fix.
tomoyo: Swicth from cred->security to task_struct->security.
security: keys: annotate implicit fall throughs
security: keys: annotate implicit fall throughs
security: keys: annotate implicit fall through
capabilities:: annotate implicit fall through
...
|
