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Merge tag 'keys-acl-20190703' of 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
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>
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>
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>
Properly start the enumeration associated with match_table_t at zero,
making Opt_err/Opt_error the last enumeration value.
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* Add support for the security features of nvdimm devices that
implement a security model similar to ATA hard drive security. The
security model supports locking access to the media at
device-power-loss, to be unlocked with a passphrase, and secure-erase
(crypto-scramble).
Unlike the ATA security case where the kernel expects device
security to be managed in a pre-OS environment, the libnvdimm security
implementation allows key provisioning and key-operations at OS
runtime. Keys are managed with the kernel's encrypted-keys facility to
provide data-at-rest security for the libnvdimm key material. The
usage model mirrors fscrypt key management, but is driven via
libnvdimm sysfs.
* Miscellaneous updates for api usage and comment fixes.
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Merge tag 'libnvdimm-for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm updates from Dan Williams:
"The vast bulk of this update is the new support for the security
capabilities of some nvdimms.
The userspace tooling for this capability is still a work in progress,
but the changes survive the existing libnvdimm unit tests. The changes
also pass manual checkout on hardware and the new nfit_test emulation
of the security capability.
The touches of the security/keys/ files have received the necessary
acks from Mimi and David. Those changes were necessary to allow for a
new generic encrypted-key type, and allow the nvdimm sub-system to
lookup key material referenced by the libnvdimm-sysfs interface.
Summary:
- Add support for the security features of nvdimm devices that
implement a security model similar to ATA hard drive security. The
security model supports locking access to the media at
device-power-loss, to be unlocked with a passphrase, and
secure-erase (crypto-scramble).
Unlike the ATA security case where the kernel expects device
security to be managed in a pre-OS environment, the libnvdimm
security implementation allows key provisioning and key-operations
at OS runtime. Keys are managed with the kernel's encrypted-keys
facility to provide data-at-rest security for the libnvdimm key
material. The usage model mirrors fscrypt key management, but is
driven via libnvdimm sysfs.
- Miscellaneous updates for api usage and comment fixes"
* tag 'libnvdimm-for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits)
libnvdimm/security: Quiet security operations
libnvdimm/security: Add documentation for nvdimm security support
tools/testing/nvdimm: add Intel DSM 1.8 support for nfit_test
tools/testing/nvdimm: Add overwrite support for nfit_test
tools/testing/nvdimm: Add test support for Intel nvdimm security DSMs
acpi/nfit, libnvdimm/security: add Intel DSM 1.8 master passphrase support
acpi/nfit, libnvdimm/security: Add security DSM overwrite support
acpi/nfit, libnvdimm: Add support for issue secure erase DSM to Intel nvdimm
acpi/nfit, libnvdimm: Add enable/update passphrase support for Intel nvdimms
acpi/nfit, libnvdimm: Add disable passphrase support to Intel nvdimm.
acpi/nfit, libnvdimm: Add unlock of nvdimm support for Intel DIMMs
acpi/nfit, libnvdimm: Add freeze security support to Intel nvdimm
acpi/nfit, libnvdimm: Introduce nvdimm_security_ops
keys-encrypted: add nvdimm key format type to encrypted keys
keys: Export lookup_user_key to external users
acpi/nfit, libnvdimm: Store dimm id as a member to struct nvdimm
libnvdimm, namespace: Replace kmemdup() with kstrndup()
libnvdimm, label: Switch to bitmap_zalloc()
ACPI/nfit: Adjust annotation for why return 0 if fail to find NFIT at start
libnvdimm, bus: Check id immediately following ida_simple_get
...
Adding nvdimm key format type to encrypted keys in order to limit the size
of the key to 32bytes.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
'shash' algorithms are always synchronous, so passing CRYPTO_ALG_ASYNC
in the mask to crypto_alloc_shash() has no effect. Many users therefore
already don't pass it, but some still do. This inconsistency can cause
confusion, especially since the way the 'mask' argument works is
somewhat counterintuitive.
Thus, just remove the unneeded CRYPTO_ALG_ASYNC flags.
This patch shouldn't change any actual behavior.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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>
A key of type "encrypted" references a "master key" which is used to
encrypt and decrypt the encrypted key's payload. However, when we
accessed the master key's payload, we failed to handle the case where
the master key has been revoked, which sets the payload pointer to NULL.
Note that request_key() *does* skip revoked keys, but there is still a
window where the key can be revoked before we acquire its semaphore.
Fix it by checking for a NULL payload, treating it like a key which was
already revoked at the time it was requested.
This was an issue for master keys of type "user" only. Master keys can
also be of type "trusted", but those cannot be revoked.
Fixes: 7e70cb4978 ("keys: add new key-type encrypted")
Reviewed-by: James Morris <james.l.morris@oracle.com>
Cc: <stable@vger.kernel.org> [v2.6.38+]
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: David Safford <safford@us.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
around. Highlights include:
- Conversion of a bunch of security documentation into RST
- The conversion of the remaining DocBook templates by The Amazing
Mauro Machine. We can now drop the entire DocBook build chain.
- The usual collection of fixes and minor updates.
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Merge tag 'docs-4.13' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"There has been a fair amount of activity in the docs tree this time
around. Highlights include:
- Conversion of a bunch of security documentation into RST
- The conversion of the remaining DocBook templates by The Amazing
Mauro Machine. We can now drop the entire DocBook build chain.
- The usual collection of fixes and minor updates"
* tag 'docs-4.13' of git://git.lwn.net/linux: (90 commits)
scripts/kernel-doc: handle DECLARE_HASHTABLE
Documentation: atomic_ops.txt is core-api/atomic_ops.rst
Docs: clean up some DocBook loose ends
Make the main documentation title less Geocities
Docs: Use kernel-figure in vidioc-g-selection.rst
Docs: fix table problems in ras.rst
Docs: Fix breakage with Sphinx 1.5 and upper
Docs: Include the Latex "ifthen" package
doc/kokr/howto: Only send regression fixes after -rc1
docs-rst: fix broken links to dynamic-debug-howto in kernel-parameters
doc: Document suitability of IBM Verse for kernel development
Doc: fix a markup error in coding-style.rst
docs: driver-api: i2c: remove some outdated information
Documentation: DMA API: fix a typo in a function name
Docs: Insert missing space to separate link from text
doc/ko_KR/memory-barriers: Update control-dependencies example
Documentation, kbuild: fix typo "minimun" -> "minimum"
docs: Fix some formatting issues in request-key.rst
doc: ReSTify keys-trusted-encrypted.txt
doc: ReSTify keys-request-key.txt
...
For keys of type "encrypted", consistently zero sensitive key material
before freeing it. This was already being done for the decrypted
payloads of encrypted keys, but not for the master key and the keys
derived from the master key.
Out of an abundance of caution and because it is trivial to do so, also
zero buffers containing the key payload in encrypted form, although
depending on how the encrypted-keys feature is used such information
does not necessarily need to be kept secret.
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: David Safford <safford@us.ibm.com>
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>
MACs should, in general, be compared using crypto_memneq() to prevent
timing attacks.
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
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>
The encrypted-keys module was using a single global HMAC transform,
which could be rekeyed by multiple threads concurrently operating on
different keys, causing incorrect HMAC values to be calculated. Fix
this by allocating a new HMAC transform whenever we need to calculate a
HMAC. Also simplify things a bit by allocating the shash_desc's using
SHASH_DESC_ON_STACK() for both the HMAC and unkeyed hashes.
The following script reproduces the bug:
keyctl new_session
keyctl add user master "abcdefghijklmnop" @s
for i in $(seq 2); do
(
set -e
for j in $(seq 1000); do
keyid=$(keyctl add encrypted desc$i "new user:master 25" @s)
datablob="$(keyctl pipe $keyid)"
keyctl unlink $keyid > /dev/null
keyid=$(keyctl add encrypted desc$i "load $datablob" @s)
keyctl unlink $keyid > /dev/null
done
) &
done
Output with bug:
[ 439.691094] encrypted_key: bad hmac (-22)
add_key: Invalid argument
add_key: Invalid argument
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
With the 'encrypted' key type it was possible for userspace to provide a
data blob ending with a master key description shorter than expected,
e.g. 'keyctl add encrypted desc "new x" @s'. When validating such a
master key description, validate_master_desc() could read beyond the end
of the buffer. Fix this by using strncmp() instead of memcmp(). [Also
clean up the code to deduplicate some logic.]
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Since v4.9, the crypto API cannot (normally) be used to encrypt/decrypt
stack buffers because the stack may be virtually mapped. Fix this for
the padding buffers in encrypted-keys by using ZERO_PAGE for the
encryption padding and by allocating a temporary heap buffer for the
decryption padding.
Tested with CONFIG_DEBUG_SG=y:
keyctl new_session
keyctl add user master "abcdefghijklmnop" @s
keyid=$(keyctl add encrypted desc "new user:master 25" @s)
datablob="$(keyctl pipe $keyid)"
keyctl unlink $keyid
keyid=$(keyctl add encrypted desc "load $datablob" @s)
datablob2="$(keyctl pipe $keyid)"
[ "$datablob" = "$datablob2" ] && echo "Success!"
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 4.9+
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>
Omit an extra message for a memory allocation failure in this function.
This issue was detected by using the Coccinelle software.
Link: http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdf
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
rcu_dereference_key() and user_key_payload() are currently being used in
two different, incompatible ways:
(1) As a wrapper to rcu_dereference() - when only the RCU read lock used
to protect the key.
(2) As a wrapper to rcu_dereference_protected() - when the key semaphor is
used to protect the key and the may be being modified.
Fix this by splitting both of the key wrappers to produce:
(1) RCU accessors for keys when caller has the key semaphore locked:
dereference_key_locked()
user_key_payload_locked()
(2) RCU accessors for keys when caller holds the RCU read lock:
dereference_key_rcu()
user_key_payload_rcu()
This should fix following warning in the NFS idmapper
===============================
[ INFO: suspicious RCU usage. ]
4.10.0 #1 Tainted: G W
-------------------------------
./include/keys/user-type.h:53 suspicious rcu_dereference_protected() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 0
1 lock held by mount.nfs/5987:
#0: (rcu_read_lock){......}, at: [<d000000002527abc>] nfs_idmap_get_key+0x15c/0x420 [nfsv4]
stack backtrace:
CPU: 1 PID: 5987 Comm: mount.nfs Tainted: G W 4.10.0 #1
Call Trace:
dump_stack+0xe8/0x154 (unreliable)
lockdep_rcu_suspicious+0x140/0x190
nfs_idmap_get_key+0x380/0x420 [nfsv4]
nfs_map_name_to_uid+0x2a0/0x3b0 [nfsv4]
decode_getfattr_attrs+0xfac/0x16b0 [nfsv4]
decode_getfattr_generic.constprop.106+0xbc/0x150 [nfsv4]
nfs4_xdr_dec_lookup_root+0xac/0xb0 [nfsv4]
rpcauth_unwrap_resp+0xe8/0x140 [sunrpc]
call_decode+0x29c/0x910 [sunrpc]
__rpc_execute+0x140/0x8f0 [sunrpc]
rpc_run_task+0x170/0x200 [sunrpc]
nfs4_call_sync_sequence+0x68/0xa0 [nfsv4]
_nfs4_lookup_root.isra.44+0xd0/0xf0 [nfsv4]
nfs4_lookup_root+0xe0/0x350 [nfsv4]
nfs4_lookup_root_sec+0x70/0xa0 [nfsv4]
nfs4_find_root_sec+0xc4/0x100 [nfsv4]
nfs4_proc_get_rootfh+0x5c/0xf0 [nfsv4]
nfs4_get_rootfh+0x6c/0x190 [nfsv4]
nfs4_server_common_setup+0xc4/0x260 [nfsv4]
nfs4_create_server+0x278/0x3c0 [nfsv4]
nfs4_remote_mount+0x50/0xb0 [nfsv4]
mount_fs+0x74/0x210
vfs_kern_mount+0x78/0x220
nfs_do_root_mount+0xb0/0x140 [nfsv4]
nfs4_try_mount+0x60/0x100 [nfsv4]
nfs_fs_mount+0x5ec/0xda0 [nfs]
mount_fs+0x74/0x210
vfs_kern_mount+0x78/0x220
do_mount+0x254/0xf70
SyS_mount+0x94/0x100
system_call+0x38/0xe0
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
I don't think GCC has figured out how to optimize the memset() away, but
they might eventually so let's future proof this code a bit.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
This function has two callers and neither are able to handle a NULL
return. Really, -EINVAL is the correct thing return here anyway. This
fixes some static checker warnings like:
security/keys/encrypted-keys/encrypted.c:709 encrypted_key_decrypt()
error: uninitialized symbol 'master_key'.
Fixes: 7e70cb4978 ("keys: add new key-type encrypted")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
The IV must not be modified by the skcipher operation so we need
to duplicate it.
Fixes: c3917fd9df ("KEYS: Use skcipher")
Cc: stable@vger.kernel.org
Reported-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
If a user key gets negatively instantiated, an error code is cached in the
payload area. A negatively instantiated key may be then be positively
instantiated by updating it with valid data. However, the ->update key
type method must be aware that the error code may be there.
The following may be used to trigger the bug in the user key type:
keyctl request2 user user "" @u
keyctl add user user "a" @u
which manifests itself as:
BUG: unable to handle kernel paging request at 00000000ffffff8a
IP: [<ffffffff810a376f>] __call_rcu.constprop.76+0x1f/0x280 kernel/rcu/tree.c:3046
PGD 7cc30067 PUD 0
Oops: 0002 [#1] SMP
Modules linked in:
CPU: 3 PID: 2644 Comm: a.out Not tainted 4.3.0+ #49
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
task: ffff88003ddea700 ti: ffff88003dd88000 task.ti: ffff88003dd88000
RIP: 0010:[<ffffffff810a376f>] [<ffffffff810a376f>] __call_rcu.constprop.76+0x1f/0x280
[<ffffffff810a376f>] __call_rcu.constprop.76+0x1f/0x280 kernel/rcu/tree.c:3046
RSP: 0018:ffff88003dd8bdb0 EFLAGS: 00010246
RAX: 00000000ffffff82 RBX: 0000000000000000 RCX: 0000000000000001
RDX: ffffffff81e3fe40 RSI: 0000000000000000 RDI: 00000000ffffff82
RBP: ffff88003dd8bde0 R08: ffff88007d2d2da0 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88003e8073c0 R12: 00000000ffffff82
R13: ffff88003dd8be68 R14: ffff88007d027600 R15: ffff88003ddea700
FS: 0000000000b92880(0063) GS:ffff88007fd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00000000ffffff8a CR3: 000000007cc5f000 CR4: 00000000000006e0
Stack:
ffff88003dd8bdf0 ffffffff81160a8a 0000000000000000 00000000ffffff82
ffff88003dd8be68 ffff88007d027600 ffff88003dd8bdf0 ffffffff810a39e5
ffff88003dd8be20 ffffffff812a31ab ffff88007d027600 ffff88007d027620
Call Trace:
[<ffffffff810a39e5>] kfree_call_rcu+0x15/0x20 kernel/rcu/tree.c:3136
[<ffffffff812a31ab>] user_update+0x8b/0xb0 security/keys/user_defined.c:129
[< inline >] __key_update security/keys/key.c:730
[<ffffffff8129e5c1>] key_create_or_update+0x291/0x440 security/keys/key.c:908
[< inline >] SYSC_add_key security/keys/keyctl.c:125
[<ffffffff8129fc21>] SyS_add_key+0x101/0x1e0 security/keys/keyctl.c:60
[<ffffffff8185f617>] entry_SYSCALL_64_fastpath+0x12/0x6a arch/x86/entry/entry_64.S:185
Note the error code (-ENOKEY) in EDX.
A similar bug can be tripped by:
keyctl request2 trusted user "" @u
keyctl add trusted user "a" @u
This should also affect encrypted keys - but that has to be correctly
parameterised or it will fail with EINVAL before getting to the bit that
will crashes.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
When loading encrypted-keys module, if the last check of
aes_get_sizes() in init_encrypted() fails, the driver just returns an
error without unregistering its key type. This results in the stale
entry in the list. In addition to memory leaks, this leads to a kernel
crash when registering a new key type later.
This patch fixes the problem by swapping the calls of aes_get_sizes()
and register_key_type(), and releasing resources properly at the error
paths.
Bugzilla: https://bugzilla.opensuse.org/show_bug.cgi?id=908163
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
A previous patch added a ->match_preparse() method to the key type. This is
allowed to override the function called by the iteration algorithm.
Therefore, we can just set a default that simply checks for an exact match of
the key description with the original criterion data and allow match_preparse
to override it as needed.
The key_type::match op is then redundant and can be removed, as can the
user_match() function.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Commit fc7c70e "KEYS: struct key_preparsed_payload should have two
payload pointers" erroneously modified encrypted-keys. This patch
reverts the change to that file.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
struct key_preparsed_payload should have two payload pointers to correspond
with those in struct key.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Sage Weil <sage@redhat.com>
The usage of strict_strto*() is not preferred, because
strict_strto*() is obsolete. Thus, kstrto*() should be
used.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Give the key type the opportunity to preparse the payload prior to the
instantiation and update routines being called. This is done with the
provision of two new key type operations:
int (*preparse)(struct key_preparsed_payload *prep);
void (*free_preparse)(struct key_preparsed_payload *prep);
If the first operation is present, then it is called before key creation (in
the add/update case) or before the key semaphore is taken (in the update and
instantiate cases). The second operation is called to clean up if the first
was called.
preparse() is given the opportunity to fill in the following structure:
struct key_preparsed_payload {
char *description;
void *type_data[2];
void *payload;
const void *data;
size_t datalen;
size_t quotalen;
};
Before the preparser is called, the first three fields will have been cleared,
the payload pointer and size will be stored in data and datalen and the default
quota size from the key_type struct will be stored into quotalen.
The preparser may parse the payload in any way it likes and may store data in
the type_data[] and payload fields for use by the instantiate() and update()
ops.
The preparser may also propose a description for the key by attaching it as a
string to the description field. This can be used by passing a NULL or ""
description to the add_key() system call or the key_create_or_update()
function. This cannot work with request_key() as that required the description
to tell the upcall about the key to be created.
This, for example permits keys that store PGP public keys to generate their own
name from the user ID and public key fingerprint in the key.
The instantiate() and update() operations are then modified to look like this:
int (*instantiate)(struct key *key, struct key_preparsed_payload *prep);
int (*update)(struct key *key, struct key_preparsed_payload *prep);
and the new payload data is passed in *prep, whether or not it was preparsed.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Enabling CONFIG_PROVE_RCU and CONFIG_SPARSE_RCU_POINTER resulted in
"suspicious rcu_dereference_check() usage!" and "incompatible types
in comparison expression (different address spaces)" messages.
Access the masterkey directly when holding the rwsem.
Changelog v1:
- Use either rcu_read_lock()/rcu_derefence_key()/rcu_read_unlock()
or remove the unnecessary rcu_derefence() - David Howells
Reported-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Define rcu_assign_keypointer(), which uses the key payload.rcudata instead
of payload.data, to resolve the CONFIG_SPARSE_RCU_POINTER message:
"incompatible types in comparison expression (different address spaces)"
Replace the rcu_assign_pointer() calls in encrypted/trusted keys with
rcu_assign_keypointer().
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
There is no functional change.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mimi Zohar <zohar@us.ibm.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For each hex2bin call in encrypted keys, check that the ascii hex string
is valid. On failure, return -EINVAL.
Changelog v1:
- hex2bin now returns an int
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Encrypted keys are decrypted/encrypted using either a trusted-key or,
for those systems without a TPM, a user-defined key. This patch
removes the trusted-keys and TCG_TPM dependencies.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>