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2016-12-14Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "After a lot of discussion and work we have finally reachanged a basic understanding of what is necessary to make unprivileged mounts safe in the presence of EVM and IMA xattrs which the last commit in this series reflects. While technically it is a revert the comments it adds are important for people not getting confused in the future. Clearing up that confusion allows us to seriously work on unprivileged mounts of fuse in the next development cycle. The rest of the fixes in this set are in the intersection of user namespaces, ptrace, and exec. I started with the first fix which started a feedback cycle of finding additional issues during review and fixing them. Culiminating in a fix for a bug that has been present since at least Linux v1.0. Potentially these fixes were candidates for being merged during the rc cycle, and are certainly backport candidates but enough little things turned up during review and testing that I decided they should be handled as part of the normal development process just to be certain there were not any great surprises when it came time to backport some of these fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: Revert "evm: Translate user/group ids relative to s_user_ns when computing HMAC" exec: Ensure mm->user_ns contains the execed files ptrace: Don't allow accessing an undumpable mm ptrace: Capture the ptracer's creds not PT_PTRACE_CAP mm: Add a user_ns owner to mm_struct and fix ptrace permission checks
2016-12-02Revert "evm: Translate user/group ids relative to s_user_ns when computing HMAC"Eric W. Biederman
This reverts commit 0b3c9761d1e405514a551ed24d3ea89aea26ce14. Seth Forshee <seth.forshee@canonical.com> writes: > All right, I think 0b3c9761d1e405514a551ed24d3ea89aea26ce14 should be > reverted then. EVM is a machine-local integrity mechanism, and so it > makes sense that the signature would be based on the kernel's notion of > the uid and not the filesystem's. I added a commment explaining why the EVM hmac needs to be in the kernel's notion of uid and gid, not the filesystems to prevent remounting the filesystem and gaining unwaranted trust in files. Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-11-13security/integrity: Harden against malformed xattrsSeth Forshee
In general the handling of IMA/EVM xattrs is good, but I found a few locations where either the xattr size or the value of the type field in the xattr are not checked. Add a few simple checks to these locations to prevent malformed or malicious xattrs from causing problems. Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-11-13ima: include the reason for TPM-bypass modeMimi Zohar
This patch includes the reason for going into TPM-bypass mode and not using the TPM. Signed-off-by: Mimi Zohar (zohar@linux.vnet.ibm>
2016-11-13Revert "ima: limit file hash setting by user to fix and log modes"Mimi Zohar
Userspace applications have been modified to write security xattrs, but they are not context aware. In the case of security.ima, the security xattr can be either a file hash or a file signature. Permitting writing one, but not the other requires the application to be context aware. In addition, userspace applications might write files to a staging area, which might not be in policy, and then change some file metadata (eg. owner) making it in policy. As a result, these files are not labeled properly. This reverts commit c68ed80c97d9720f51ef31fe91560fdd1e121533, which prevents writing file hashes as security.ima xattrs. Requested-by: Patrick Ohly <patrick.ohly@intel.com> Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-11-13ima: fix memory leak in ima_release_policyEric Richter
When the "policy" securityfs file is opened for read, it is opened as a sequential file. However, when it is eventually released, there is no cleanup for the sequential file, therefore some memory is leaked. This patch adds a call to seq_release() in ima_release_policy() to clean up the memory when the file is opened for read. Fixes: 80eae209d63a IMA: allow reading back the current policy Reported-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Tested-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-10-10Merge branch 'work.xattr' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs xattr updates from Al Viro: "xattr stuff from Andreas This completes the switch to xattr_handler ->get()/->set() from ->getxattr/->setxattr/->removexattr" * 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: Remove {get,set,remove}xattr inode operations xattr: Stop calling {get,set,remove}xattr inode operations vfs: Check for the IOP_XATTR flag in listxattr xattr: Add __vfs_{get,set,remove}xattr helpers libfs: Use IOP_XATTR flag for empty directory handling vfs: Use IOP_XATTR flag for bad-inode handling vfs: Add IOP_XATTR inode operations flag vfs: Move xattr_resolve_name to the front of fs/xattr.c ecryptfs: Switch to generic xattr handlers sockfs: Get rid of getxattr iop sockfs: getxattr: Fail with -EOPNOTSUPP for invalid attribute names kernfs: Switch to generic xattr handlers hfs: Switch to generic xattr handlers jffs2: Remove jffs2_{get,set,remove}xattr macros xattr: Remove unnecessary NULL attribute name check
2016-10-07xattr: Add __vfs_{get,set,remove}xattr helpersAndreas Gruenbacher
Right now, various places in the kernel check for the existence of getxattr, setxattr, and removexattr inode operations and directly call those operations. Switch to helper functions and test for the IOP_XATTR flag instead. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Acked-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-16ima: use file_dentry()Miklos Szeredi
Ima tries to call ->setxattr() on overlayfs dentry after having locked underlying inode, which results in a deadlock. Reported-by: Krisztian Litkey <kli@iki.fi> Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org> # v4.2 Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-07-29Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "Highlights: - TPM core and driver updates/fixes - IPv6 security labeling (CALIPSO) - Lots of Apparmor fixes - Seccomp: remove 2-phase API, close hole where ptrace can change syscall #" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (156 commits) apparmor: fix SECURITY_APPARMOR_HASH_DEFAULT parameter handling tpm: Add TPM 2.0 support to the Nuvoton i2c driver (NPCT6xx family) tpm: Factor out common startup code tpm: use devm_add_action_or_reset tpm2_i2c_nuvoton: add irq validity check tpm: read burstcount from TPM_STS in one 32-bit transaction tpm: fix byte-order for the value read by tpm2_get_tpm_pt tpm_tis_core: convert max timeouts from msec to jiffies apparmor: fix arg_size computation for when setprocattr is null terminated apparmor: fix oops, validate buffer size in apparmor_setprocattr() apparmor: do not expose kernel stack apparmor: fix module parameters can be changed after policy is locked apparmor: fix oops in profile_unpack() when policy_db is not present apparmor: don't check for vmalloc_addr if kvzalloc() failed apparmor: add missing id bounds check on dfa verification apparmor: allow SYS_CAP_RESOURCE to be sufficient to prlimit another task apparmor: use list_next_entry instead of list_entry_next apparmor: fix refcount race when finding a child profile apparmor: fix ref count leak when profile sha1 hash is read apparmor: check that xindex is in trans_table bounds ...
2016-07-05evm: Translate user/group ids relative to s_user_ns when computing HMACSeth Forshee
The EVM HMAC should be calculated using the on disk user and group ids, so the k[ug]ids in the inode must be translated relative to the s_user_ns of the inode's super block. Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-06-30ima: extend the measurement entry specific pcrEric Richter
Extend the PCR supplied as a parameter, instead of assuming that the measurement entry uses the default configured PCR. Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30ima: change integrity cache to store measured pcrEric Richter
IMA avoids re-measuring files by storing the current state as a flag in the integrity cache. It will then skip adding a new measurement log entry if the cache reports the file as already measured. If a policy measures an already measured file to a new PCR, the measurement will not be added to the list. This patch implements a new bitfield for specifying which PCR the file was measured into, rather than if it was measured. Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30ima: redefine duplicate template entriesEric Richter
Template entry duplicates are prevented from being added to the measurement list by checking a hash table that contains the template entry digests. However, the PCR value is not included in this comparison, so duplicate template entry digests with differing PCRs may be dropped. This patch redefines duplicate template entries as template entries with the same digest and same PCR values. Reported-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30ima: change ima_measurements_show() to display the entry specific pcrEric Richter
IMA assumes that the same default Kconfig PCR is extended for each entry. This patch replaces the default configured PCR with the policy defined PCR. Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30ima: include pcr for each measurement log entryEric Richter
The IMA measurement list entries include the Kconfig defined PCR value. This patch defines a new ima_template_entry field for including the PCR as specified in the policy rule. Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30ima: extend ima_get_action() to return the policy pcrEric Richter
Different policy rules may extend different PCRs. This patch retrieves the specific PCR for the matched rule. Subsequent patches will include the rule specific PCR in the measurement list and extend the appropriate PCR. Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30ima: add policy support for extending different pcrsEric Richter
This patch defines a new IMA measurement policy rule option "pcr=", which allows extending different PCRs on a per rule basis. For example, the system independent files could extend the default IMA Kconfig specified PCR, while the system dependent files could extend a different PCR. The following is an example of this usage with an SELinux policy; the rule would extend PCR 11 with system configuration files: measure func=FILE_CHECK mask=MAY_READ obj_type=system_conf_t pcr=11 Changelog v3: - FIELD_SIZEOF returns bytes, not bits. Fixed INVALID_PCR Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30integrity: add measured_pcrs field to integrity cacheEric Richter
To keep track of which measurements have been extended to which PCRs, this patch defines a new integrity_iint_cache field named measured_pcrs. This field is a bitmask of the PCRs measured. Each bit corresponds to a PCR index. For example, bit 10 corresponds to PCR 10. Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-05-20security/integrity/ima/ima_policy.c: use %pU to output UUID in printable formatAndy Shevchenko
Instead of open coded variant re-use extension that vsprintf.c provides us for ages. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-19Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "Highlights: - A new LSM, "LoadPin", from Kees Cook is added, which allows forcing of modules and firmware to be loaded from a specific device (this is from ChromeOS, where the device as a whole is verified cryptographically via dm-verity). This is disabled by default but can be configured to be enabled by default (don't do this if you don't know what you're doing). - Keys: allow authentication data to be stored in an asymmetric key. Lots of general fixes and updates. - SELinux: add restrictions for loading of kernel modules via finit_module(). Distinguish non-init user namespace capability checks. Apply execstack check on thread stacks" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (48 commits) LSM: LoadPin: provide enablement CONFIG Yama: use atomic allocations when reporting seccomp: Fix comment typo ima: add support for creating files using the mknodat syscall ima: fix ima_inode_post_setattr vfs: forbid write access when reading a file into memory fs: fix over-zealous use of "const" selinux: apply execstack check on thread stacks selinux: distinguish non-init user namespace capability checks LSM: LoadPin for kernel file loading restrictions fs: define a string representation of the kernel_read_file_id enumeration Yama: consolidate error reporting string_helpers: add kstrdup_quotable_file string_helpers: add kstrdup_quotable_cmdline string_helpers: add kstrdup_quotable selinux: check ss_initialized before revalidating an inode label selinux: delay inode label lookup as long as possible selinux: don't revalidate an inode's label when explicitly setting it selinux: Change bool variable name to index. KEYS: Add KEYCTL_DH_COMPUTE command ...
2016-05-17Merge branch 'work.const-path' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull 'struct path' constification update from Al Viro: "'struct path' is passed by reference to a bunch of Linux security methods; in theory, there's nothing to stop them from modifying the damn thing and LSM community being what it is, sooner or later some enterprising soul is going to decide that it's a good idea. Let's remove the temptation and constify all of those..." * 'work.const-path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: constify ima_d_path() constify security_sb_pivotroot() constify security_path_chroot() constify security_path_{link,rename} apparmor: remove useless checks for NULL ->mnt constify security_path_{mkdir,mknod,symlink} constify security_path_{unlink,rmdir} apparmor: constify common_perm_...() apparmor: constify aa_path_link() apparmor: new helper - common_path_perm() constify chmod_common/security_path_chmod constify security_sb_mount() constify chown_common/security_path_chown tomoyo: constify assorted struct path * apparmor_path_truncate(): path->mnt is never NULL constify vfs_truncate() constify security_path_truncate() [apparmor] constify struct path * in a bunch of helpers
2016-05-17Merge branch 'ovl-fixes' into for-linusAl Viro
Backmerge to resolve a conflict in ovl_lookup_real(); "ovl_lookup_real(): use lookup_one_len_unlocked()" instead, but it was too late in the cycle to rebase.
2016-05-06Merge tag 'keys-next-20160505' of ↵James Morris
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into next
2016-05-04Merge branch 'keys-trust' into keys-nextDavid Howells
Here's a set of patches that changes how certificates/keys are determined to be trusted. That's currently a two-step process: (1) Up until recently, when an X.509 certificate was parsed - no matter the source - it was judged against the keys in .system_keyring, assuming those keys to be trusted if they have KEY_FLAG_TRUSTED set upon them. This has just been changed such that any key in the .ima_mok keyring, if configured, may also be used to judge the trustworthiness of a new certificate, whether or not the .ima_mok keyring is meant to be consulted for whatever process is being undertaken. If a certificate is determined to be trustworthy, KEY_FLAG_TRUSTED will be set upon a key it is loaded into (if it is loaded into one), no matter what the key is going to be loaded for. (2) If an X.509 certificate is loaded into a key, then that key - if KEY_FLAG_TRUSTED gets set upon it - can be linked into any keyring with KEY_FLAG_TRUSTED_ONLY set upon it. This was meant to be the system keyring only, but has been extended to various IMA keyrings. A user can at will link any key marked KEY_FLAG_TRUSTED into any keyring marked KEY_FLAG_TRUSTED_ONLY if the relevant permissions masks permit it. These patches change that: (1) Trust becomes a matter of consulting the ring of trusted keys supplied when the trust is evaluated only. (2) Every keyring can be supplied with its own manager function to restrict what may be added to that keyring. This is called whenever a key is to be linked into the keyring to guard against a key being created in one keyring and then linked across. This function is supplied with the keyring and the key type and payload[*] of the key being linked in for use in its evaluation. It is permitted to use other data also, such as the contents of other keyrings such as the system keyrings. [*] The type and payload are supplied instead of a key because as an optimisation this function may be called whilst creating a key and so may reject the proposed key between preparse and allocation. (3) A default manager function is provided that permits keys to be restricted to only asymmetric keys that are vouched for by the contents of the system keyring. A second manager function is provided that just rejects with EPERM. (4) A key allocation flag, KEY_ALLOC_BYPASS_RESTRICTION, is made available so that the kernel can initialise keyrings with keys that form the root of the trust relationship. (5) KEY_FLAG_TRUSTED and KEY_FLAG_TRUSTED_ONLY are removed, along with key_preparsed_payload::trusted. This change also makes it possible in future for userspace to create a private set of trusted keys and then to have it sealed by setting a manager function where the private set is wholly independent of the kernel's trust relationships. Further changes in the set involve extracting certain IMA special keyrings and making them generally global: (*) .system_keyring is renamed to .builtin_trusted_keys and remains read only. It carries only keys built in to the kernel. It may be where UEFI keys should be loaded - though that could better be the new secondary keyring (see below) or a separate UEFI keyring. (*) An optional secondary system keyring (called .secondary_trusted_keys) is added to replace the IMA MOK keyring. (*) Keys can be added to the secondary keyring by root if the keys can be vouched for by either ring of system keys. (*) Module signing and kexec only use .builtin_trusted_keys and do not use the new secondary keyring. (*) Config option SYSTEM_TRUSTED_KEYS now depends on ASYMMETRIC_KEY_TYPE as that's the only type currently permitted on the system keyrings. (*) A new config option, IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY, is provided to allow keys to be added to IMA keyrings, subject to the restriction that such keys are validly signed by a key already in the system keyrings. If this option is enabled, but secondary keyrings aren't, additions to the IMA keyrings will be restricted to signatures verifiable by keys in the builtin system keyring only. Signed-off-by: David Howells <dhowells@redhat.com>
2016-05-04ima: fix the string representation of the LSM/IMA hook enumeration orderingMimi Zohar
This patch fixes the string representation of the LSM/IMA hook enumeration ordering used for displaying the IMA policy. Fixes: d9ddf077bb85 ("ima: support for kexec image and initramfs") Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Tested-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-05-01ima: add support for creating files using the mknodat syscallMimi Zohar
Commit 3034a14 "ima: pass 'opened' flag to identify newly created files" stopped identifying empty files as new files. However new empty files can be created using the mknodat syscall. On systems with IMA-appraisal enabled, these empty files are not labeled with security.ima extended attributes properly, preventing them from subsequently being opened in order to write the file data contents. This patch defines a new hook named ima_post_path_mknod() to mark these empty files, created using mknodat, as new in order to allow the file data contents to be written. In addition, files with security.ima xattrs containing a file signature are considered "immutable" and can not be modified. The file contents need to be written, before signing the file. This patch relaxes this requirement for new files, allowing the file signature to be written before the file contents. Changelog: - defer identifying files with signatures stored as security.ima (based on Dmitry Rozhkov's comments) - removing tests (eg. dentry, dentry->d_inode, inode->i_size == 0) (based on Al's review) Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Al Viro <<viro@zeniv.linux.org.uk> Tested-by: Dmitry Rozhkov <dmitry.rozhkov@linux.intel.com>
2016-05-01ima: fix ima_inode_post_setattrMimi Zohar
Changing file metadata (eg. uid, guid) could result in having to re-appraise a file's integrity, but does not change the "new file" status nor the security.ima xattr. The IMA_PERMIT_DIRECTIO and IMA_DIGSIG_REQUIRED flags are policy rule specific. This patch only resets these flags, not the IMA_NEW_FILE or IMA_DIGSIG flags. With this patch, changing the file timestamp will not remove the file signature on new files. Reported-by: Dmitry Rozhkov <dmitry.rozhkov@linux.intel.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Tested-by: Dmitry Rozhkov <dmitry.rozhkov@linux.intel.com>
2016-04-12security: integrity: Remove select to deleted option PUBLIC_KEY_ALGO_RSAAndreas Ziegler
Commit d43de6c780a8 ("akcipher: Move the RSA DER encoding check to the crypto layer") removed the Kconfig option PUBLIC_KEY_ALGO_RSA, but forgot to remove a 'select' to this option in the definition of INTEGRITY_ASYMMETRIC_KEYS. Let's remove the select, as it's ineffective now. Signed-off-by: Andreas Ziegler <andreas.ziegler@fau.de> Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-11IMA: Use the the system trusted keyrings instead of .ima_mokDavid Howells
Add a config option (IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY) that, when enabled, allows keys to be added to the IMA keyrings by userspace - with the restriction that each must be signed by a key in the system trusted keyrings. EPERM will be returned if this option is disabled, ENOKEY will be returned if no authoritative key can be found and EKEYREJECTED will be returned if the signature doesn't match. Other errors such as ENOPKG may also be returned. If this new option is enabled, the builtin system keyring is searched, as is the secondary system keyring if that is also enabled. Intermediate keys between the builtin system keyring and the key being added can be added to the secondary keyring (which replaces .ima_mok) to form a trust chain - provided they are also validly signed by a key in one of the trusted keyrings. The .ima_mok keyring is then removed and the IMA blacklist keyring gets its own config option (IMA_BLACKLIST_KEYRING). Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-04-11KEYS: Remove KEY_FLAG_TRUSTED and KEY_ALLOC_TRUSTEDDavid Howells
Remove KEY_FLAG_TRUSTED and KEY_ALLOC_TRUSTED as they're no longer meaningful. Also we can drop the trusted flag from the preparse structure. Given this, we no longer need to pass the key flags through to restrict_link(). Further, we can now get rid of keyring_restrict_trusted_only() also. Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-11KEYS: Move the point of trust determination to __key_link()David Howells
Move the point at which a key is determined to be trustworthy to __key_link() so that we use the contents of the keyring being linked in to to determine whether the key being linked in is trusted or not. What is 'trusted' then becomes a matter of what's in the keyring. Currently, the test is done when the key is parsed, but given that at that point we can only sensibly refer to the contents of the system trusted keyring, we can only use that as the basis for working out the trustworthiness of a new key. With this change, a trusted keyring is a set of keys that once the trusted-only flag is set cannot be added to except by verification through one of the contained keys. Further, adding a key into a trusted keyring, whilst it might grant trustworthiness in the context of that keyring, does not automatically grant trustworthiness in the context of a second keyring to which it could be secondarily linked. To accomplish this, the authentication data associated with the key source must now be retained. For an X.509 cert, this means the contents of the AuthorityKeyIdentifier and the signature data. If system keyrings are disabled then restrict_link_by_builtin_trusted() resolves to restrict_link_reject(). The integrity digital signature code still works correctly with this as it was previously using KEY_FLAG_TRUSTED_ONLY, which doesn't permit anything to be added if there is no system keyring against which trust can be determined. Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-11KEYS: Add a facility to restrict new links into a keyringDavid Howells
Add a facility whereby proposed new links to be added to a keyring can be vetted, permitting them to be rejected if necessary. This can be used to block public keys from which the signature cannot be verified or for which the signature verification fails. It could also be used to provide blacklisting. This affects operations like add_key(), KEYCTL_LINK and KEYCTL_INSTANTIATE. To this end: (1) A function pointer is added to the key struct that, if set, points to the vetting function. This is called as: int (*restrict_link)(struct key *keyring, const struct key_type *key_type, unsigned long key_flags, const union key_payload *key_payload), where 'keyring' will be the keyring being added to, key_type and key_payload will describe the key being added and key_flags[*] can be AND'ed with KEY_FLAG_TRUSTED. [*] This parameter will be removed in a later patch when KEY_FLAG_TRUSTED is removed. The function should return 0 to allow the link to take place or an error (typically -ENOKEY, -ENOPKG or -EKEYREJECTED) to reject the link. The pointer should not be set directly, but rather should be set through keyring_alloc(). Note that if called during add_key(), preparse is called before this method, but a key isn't actually allocated until after this function is called. (2) KEY_ALLOC_BYPASS_RESTRICTION is added. This can be passed to key_create_or_update() or key_instantiate_and_link() to bypass the restriction check. (3) KEY_FLAG_TRUSTED_ONLY is removed. The entire contents of a keyring with this restriction emplaced can be considered 'trustworthy' by virtue of being in the keyring when that keyring is consulted. (4) key_alloc() and keyring_alloc() take an extra argument that will be used to set restrict_link in the new key. This ensures that the pointer is set before the key is published, thus preventing a window of unrestrictedness. Normally this argument will be NULL. (5) As a temporary affair, keyring_restrict_trusted_only() is added. It should be passed to keyring_alloc() as the extra argument instead of setting KEY_FLAG_TRUSTED_ONLY on a keyring. This will be replaced in a later patch with functions that look in the appropriate places for authoritative keys. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-04-11->getxattr(): pass dentry and inode as separate argumentsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-10don't bother with ->d_inode->i_sb - it's always equal to ->d_sbAl Viro
... and neither can ever be NULL Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-28constify ima_d_path()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-17Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security layer updates from James Morris: "There are a bunch of fixes to the TPM, IMA, and Keys code, with minor fixes scattered across the subsystem. IMA now requires signed policy, and that policy is also now measured and appraised" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (67 commits) X.509: Make algo identifiers text instead of enum akcipher: Move the RSA DER encoding check to the crypto layer crypto: Add hash param to pkcs1pad sign-file: fix build with CMS support disabled MAINTAINERS: update tpmdd urls MODSIGN: linux/string.h should be #included to get memcpy() certs: Fix misaligned data in extra certificate list X.509: Handle midnight alternative notation in GeneralizedTime X.509: Support leap seconds Handle ISO 8601 leap seconds and encodings of midnight in mktime64() X.509: Fix leap year handling again PKCS#7: fix unitialized boolean 'want' firmware: change kernel read fail to dev_dbg() KEYS: Use the symbol value for list size, updated by scripts/insert-sys-cert KEYS: Reserve an extra certificate symbol for inserting without recompiling modsign: hide openssl output in silent builds tpm_tis: fix build warning with tpm_tis_resume ima: require signed IMA policy ima: measure and appraise the IMA policy itself ima: load policy using path ...
2016-03-04Merge tag 'keys-next-20160303' of ↵James Morris
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into next
2016-03-03X.509: Make algo identifiers text instead of enumDavid Howells
Make the identifier public key and digest algorithm fields text instead of enum. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-03-03akcipher: Move the RSA DER encoding check to the crypto layerDavid Howells
Move the RSA EMSA-PKCS1-v1_5 encoding from the asymmetric-key public_key subtype to the rsa crypto module's pkcs1pad template. This means that the public_key subtype no longer has any dependencies on public key type. To make this work, the following changes have been made: (1) The rsa pkcs1pad template is now used for RSA keys. This strips off the padding and returns just the message hash. (2) In a previous patch, the pkcs1pad template gained an optional second parameter that, if given, specifies the hash used. We now give this, and pkcs1pad checks the encoded message E(M) for the EMSA-PKCS1-v1_5 encoding and verifies that the correct digest OID is present. (3) The crypto driver in crypto/asymmetric_keys/rsa.c is now reduced to something that doesn't care about what the encryption actually does and and has been merged into public_key.c. (4) CONFIG_PUBLIC_KEY_ALGO_RSA is gone. Module signing must set CONFIG_CRYPTO_RSA=y instead. Thoughts: (*) Should the encoding style (eg. raw, EMSA-PKCS1-v1_5) also be passed to the padding template? Should there be multiple padding templates registered that share most of the code? Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-21ima: require signed IMA policyMimi Zohar
Require the IMA policy to be signed when additional rules can be added. v1: - initialize the policy flag - include IMA_APPRAISE_POLICY in the policy flag Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Petko Manolov <petkan@mip-labs.com> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2016-02-21ima: measure and appraise the IMA policy itselfMimi Zohar
Add support for measuring and appraising the IMA policy itself. Changelog v4: - use braces on both if/else branches, even if single line on one of the branches - Dmitry - Use the id mapping - Dmitry Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Petko Manolov <petkan@mip-labs.com> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2016-02-21ima: load policy using pathDmitry Kasatkin
We currently cannot do appraisal or signature vetting of IMA policies since we currently can only load IMA policies by writing the contents of the policy directly in, as follows: cat policy-file > <securityfs>/ima/policy If we provide the kernel the path to the IMA policy so it can load the policy itself it'd be able to later appraise or vet the file signature if it has one. This patch adds support to load the IMA policy with a given path as follows: echo /etc/ima/ima_policy > /sys/kernel/security/ima/policy Changelog v4+: - moved kernel_read_file_from_path() error messages to callers v3: - moved kernel_read_file_from_path() to a separate patch v2: - after re-ordering the patches, replace calling integrity_kernel_read() to read the file with kernel_read_file_from_path() (Mimi) - Patch description re-written by Luis R. Rodriguez Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-02-21ima: support for kexec image and initramfsMimi Zohar
Add IMA policy support for measuring/appraising the kexec image and initramfs. Two new IMA policy identifiers KEXEC_KERNEL_CHECK and KEXEC_INITRAMFS_CHECK are defined. Example policy rules: measure func=KEXEC_KERNEL_CHECK appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig measure func=KEXEC_INITRAMFS_CHECK appraise func=KEXEC_INITRAMFS_CHECK appraise_type=imasig Moving the enumeration to the vfs layer simplified the patches, allowing the IMA changes, for the most part, to be separated from the other changes. Unfortunately, passing either a kernel_read_file_id or a ima_hooks enumeration within IMA is messy. Option 1: duplicate kernel_read_file enumeration in ima_hooks enum kernel_read_file_id { ... READING_KEXEC_IMAGE, READING_KEXEC_INITRAMFS, READING_MAX_ID enum ima_hooks { ... KEXEC_KERNEL_CHECK KEXEC_INITRAMFS_CHECK Option 2: define ima_hooks as extension of kernel_read_file eg: enum ima_hooks { FILE_CHECK = READING_MAX_ID, MMAP_CHECK, In order to pass both kernel_read_file_id and ima_hooks values, we would need to specify a struct containing a union. struct caller_id { union { enum ima_hooks func_id; enum kernel_read_file_id read_id; }; }; Option 3: incorportate the ima_hooks enumeration into kernel_read_file_id, perhaps changing the enumeration name. For now, duplicate the new READING_KEXEC_IMAGE/INITRAMFS in the ima_hooks. Changelog v4: - replaced switch statement with a kernel_read_file_id to an ima_hooks id mapping array - Dmitry - renamed ima_hook tokens KEXEC_CHECK and INITRAMFS_CHECK to KEXEC_KERNEL_CHECK and KEXEC_INITRAMFS_CHECK respectively - Dave Young Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Petko Manolov <petkan@mip-labs.com> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com> Cc: Dave Young <dyoung@redhat.com>
2016-02-21ima: remove firmware and module specific cached status infoMimi Zohar
Each time a file is read by the kernel, the file should be re-measured and the file signature re-appraised, based on policy. As there is no need to preserve the status information, this patch replaces the firmware and module specific cache status with a generic one named read_file. This change simplifies adding support for other files read by the kernel. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Petko Manolov <petkan@mip-labs.com> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2016-02-21module: replace copy_module_from_fd with kernel versionMimi Zohar
Replace copy_module_from_fd() with kernel_read_file_from_fd(). Although none of the upstreamed LSMs define a kernel_module_from_file hook, IMA is called, based on policy, to prevent unsigned kernel modules from being loaded by the original kernel module syscall and to measure/appraise signed kernel modules. The security function security_kernel_module_from_file() was called prior to reading a kernel module. Preventing unsigned kernel modules from being loaded by the original kernel module syscall remains on the pre-read kernel_read_file() security hook. Instead of reading the kernel module twice, once for measuring/appraising and again for loading the kernel module, the signature validation is moved to the kernel_post_read_file() security hook. This patch removes the security_kernel_module_from_file() hook and security call. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au>
2016-02-21security: define kernel_read_file hookMimi Zohar
The kernel_read_file security hook is called prior to reading the file into memory. Changelog v4+: - export security_kernel_read_file() Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Luis R. Rodriguez <mcgrof@kernel.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2016-02-21firmware: replace call to fw_read_file_contents() with kernel versionMimi Zohar
Replace the fw_read_file_contents with kernel_file_read_from_path(). Although none of the upstreamed LSMs define a kernel_fw_from_file hook, IMA is called by the security function to prevent unsigned firmware from being loaded and to measure/appraise signed firmware, based on policy. Instead of reading the firmware twice, once for measuring/appraising the firmware and again for reading the firmware contents into memory, the kernel_post_read_file() security hook calculates the file hash based on the in memory file buffer. The firmware is read once. This patch removes the LSM kernel_fw_from_file() hook and security call. Changelog v4+: - revert dropped buf->size assignment - reported by Sergey Senozhatsky v3: - remove kernel_fw_from_file hook - use kernel_file_read_from_path() - requested by Luis v2: - reordered and squashed firmware patches - fix MAX firmware size (Kees Cook) Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
2016-02-20ima: define a new hook to measure and appraise a file already in memoryMimi Zohar
This patch defines a new IMA hook ima_post_read_file() for measuring and appraising files read by the kernel. The caller loads the file into memory before calling this function, which calculates the hash followed by the normal IMA policy based processing. Changelog v5: - fail ima_post_read_file() if either file or buf is NULL v3: - rename ima_hash_and_process_file() to ima_post_read_file() v1: - split patch Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2016-02-18ima: calculate the hash of a buffer using aynchronous hash(ahash)Mimi Zohar
Setting up ahash has some overhead. Only use ahash to calculate the hash of a buffer, if the buffer is larger than ima_ahash_minsize. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>