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2018-03-22ima: relax requiring a file signature for new files with zero lengthMimi Zohar1-1/+2
[ Upstream commit b7e27bc1d42e8e0cc58b602b529c25cd0071b336 ] Custom policies can require file signatures based on LSM labels. These files are normally created and only afterwards labeled, requiring them to be signed. Instead of requiring file signatures based on LSM labels, entire filesystems could require file signatures. In this case, we need the ability of writing new files without requiring file signatures. The definition of a "new" file was originally defined as any file with a length of zero. Subsequent patches redefined a "new" file to be based on the FILE_CREATE open flag. By combining the open flag with a file size of zero, this patch relaxes the file signature requirement. Fixes: 1ac202e978e1 ima: accept previously set IMA_NEW_FILE Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-10ima: fix hash algorithm initializationBoshi Wang1-0/+4
[ Upstream commit ebe7c0a7be92bbd34c6ff5b55810546a0ee05bee ] The hash_setup function always sets the hash_setup_done flag, even when the hash algorithm is invalid. This prevents the default hash algorithm defined as CONFIG_IMA_DEFAULT_HASH from being used. This patch sets hash_setup_done flag only for valid hash algorithms. Fixes: e7a2ad7eb6f4 "ima: enable support for larger default filedata hash algorithms" Signed-off-by: Boshi Wang <wangboshi@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-24ima: do not update security.ima if appraisal status is not INTEGRITY_PASSRoberto Sassu1-0/+3
commit 020aae3ee58c1af0e7ffc4e2cc9fe4dc630338cb upstream. Commit b65a9cfc2c38 ("Untangling ima mess, part 2: deal with counters") moved the call of ima_file_check() from may_open() to do_filp_open() at a point where the file descriptor is already opened. This breaks the assumption made by IMA that file descriptors being closed belong to files whose access was granted by ima_file_check(). The consequence is that security.ima and security.evm are updated with good values, regardless of the current appraisal status. For example, if a file does not have security.ima, IMA will create it after opening the file for writing, even if access is denied. Access to the file will be allowed afterwards. Avoid this issue by checking the appraisal status before updating security.ima. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25ima: accept previously set IMA_NEW_FILEDaniel Glöckner1-2/+3
commit 1ac202e978e18f045006d75bd549612620c6ec3a upstream. Modifying the attributes of a file makes ima_inode_post_setattr reset the IMA cache flags. So if the file, which has just been created, is opened a second time before the first file descriptor is closed, verification fails since the security.ima xattr has not been written yet. We therefore have to look at the IMA_NEW_FILE even if the file already existed. With this patch there should no longer be an error when cat tries to open testfile: $ rm -f testfile $ ( echo test >&3 ; touch testfile ; cat testfile ) 3>testfile A file being new is no reason to accept that it is missing a digital signature demanded by the policy. Signed-off-by: Daniel Glöckner <dg@emlix.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-12ima: fix ima_d_path() possible race with renameMimi Zohar3-6/+24
commit bc15ed663e7e53ee4dc3e60f8d09c93a0528c694 upstream. On failure to return a pathname from ima_d_path(), a pointer to dname is returned, which is subsequently used in the IMA measurement list, the IMA audit records, and other audit logging. Saving the pointer to dname for later use has the potential to race with rename. Intead of returning a pointer to dname on failure, this patch returns a pointer to a copy of the filename. Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-12ima: fix memory leak in ima_release_policyEric Richter1-1/+1
commit 9a11a18902bc3b904353063763d06480620245a6 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-11Merge branch 'work.xattr' of ↵Linus Torvalds1-11/+10
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
2016-10-08xattr: Add __vfs_{get,set,remove}xattr helpersAndreas Gruenbacher1-11/+10
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 Szeredi2-3/+3
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>
2016-06-30ima: extend the measurement entry specific pcrEric Richter1-3/+3
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 Richter3-3/+11
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 Richter1-3/+4
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 Richter1-5/+4
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 Richter4-8/+13
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 Richter5-7/+14
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 Richter1-1/+28
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>
2016-05-21security/integrity/ima/ima_policy.c: use %pU to output UUID in printable formatAndy Shevchenko1-12/+2
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 Torvalds5-32/+61
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 ...
2016-05-18Merge branch 'work.const-path' of ↵Linus Torvalds2-2/+2
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
2016-05-06Merge tag 'keys-next-20160505' of ↵James Morris3-30/+31
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into next
2016-05-04ima: fix the string representation of the LSM/IMA hook enumeration orderingMimi Zohar1-2/+2
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 Zohar2-1/+29
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 Zohar1-1/+1
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>
2016-04-12IMA: Use the the system trusted keyrings instead of .ima_mokDavid Howells3-27/+28
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>
2016-04-12KEYS: Move the point of trust determination to __key_link()David Howells1-3/+3
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>
2016-04-12KEYS: Add a facility to restrict new links into a keyringDavid Howells1-4/+4
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>
2016-03-28constify ima_d_path()Al Viro2-2/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-02-21ima: require signed IMA policyMimi Zohar1-0/+7
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 Zohar4-3/+24
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 Kasatkin1-2/+43
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 Zohar3-7/+27
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 Zohar3-25/+22
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 Zohar1-22/+13
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 Zohar1-0/+16
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 Zohar1-11/+10
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>
2016-02-21ima: define a new hook to measure and appraise a file already in memoryMimi Zohar5-12/+46
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>
2016-02-19ima: calculate the hash of a buffer using aynchronous hash(ahash)Mimi Zohar1-2/+73
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>
2016-02-19ima: provide buffer hash calculation functionDmitry Kasatkin2-0/+49
This patch provides convenient buffer hash calculation function. Changelog v3: - fix while hash calculation - Dmitry v1: - rewrite to support loff_t sized buffers - Mimi (based on Fenguang Wu's testing) Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-02-19ima: use "ima_hooks" enum as function argumentMimi Zohar5-27/+37
Cleanup the function arguments by using "ima_hooks" enumerator as needed. 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>
2016-02-19ima: refactor ima_policy_show() to display "ima_hooks" rulesMimi Zohar1-27/+36
Define and call a function to display the "ima_hooks" rules. 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>
2016-02-19ima: separate 'security.ima' reading functionality from collectDmitry Kasatkin8-40/+33
Instead of passing pointers to pointers to ima_collect_measurent() to read and return the 'security.ima' xattr value, this patch moves the functionality to the calling process_measurement() to directly read the xattr and pass only the hash algo to the ima_collect_measurement(). Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-02-09IMA: fix non-ANSI declaration of ima_check_policy()Colin Ian King1-1/+1
ima_check_policy() has no parameters, so use the normal void parameter convention to make it match the prototype in the header file security/integrity/ima/ima.h Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-01-23wrappers for ->i_mutex accessAl Viro1-4/+4
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-03ima: ima_write_policy() limit lockingPetko Manolov1-9/+9
There is no need to hold the ima_write_mutex for so long. We only need it around ima_parse_add_rule(). Changelog: - The return path now takes into account failed kmalloc() call. Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Petko Manolov <petkan@mip-labs.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-25IMA: policy can be updated zero timesSasha Levin3-0/+14
Commit "IMA: policy can now be updated multiple times" assumed that the policy would be updated at least once. If there are zero updates, the temporary list head object will get added to the policy list, and later dereferenced as an IMA policy object, which means that invalid memory will be accessed. Changelog: - Move list_empty() test to ima_release_policy(), before audit msg - Mimi Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15security/integrity: make ima/ima_mok.c explicitly non-modularPaul Gortmaker1-3/+2
The Kconfig currently controlling compilation of this code is: ima/Kconfig:config IMA_MOK_KEYRING ima/Kconfig: bool "Create IMA machine owner keys (MOK) and blacklist keyrings" ...meaning that it currently is not being built as a module by anyone. Lets remove the couple of traces of modularity so that when reading the driver there is no doubt it really is builtin-only. Since module_init translates to device_initcall in the non-modular case, the init ordering remains unchanged with this commit. Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: James Morris <james.l.morris@oracle.com> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: linux-ima-devel@lists.sourceforge.net Cc: linux-ima-user@lists.sourceforge.net Cc: linux-security-module@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15ima: update appraise flags after policy update completesMimi Zohar1-2/+5
While creating a temporary list of new rules, the ima_appraise flag is updated, but not reverted on failure to append the new rules to the existing policy. This patch defines temp_ima_appraise flag. Only when the new rules are appended to the policy is the flag updated. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Petko Manolov <petkan@mip-labs.com>
2015-12-15IMA: prevent keys on the .ima_blacklist from being removedMimi Zohar1-0/+2
Set the KEY_FLAGS_KEEP on the .ima_blacklist to prevent userspace from removing keys from the keyring. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15IMA: allow reading back the current IMA policyPetko Manolov4-8/+253
It is often useful to be able to read back the IMA policy. It is even more important after introducing CONFIG_IMA_WRITE_POLICY. This option allows the root user to see the current policy rules. Signed-off-by: Zbigniew Jasinski <z.jasinski@samsung.com> Signed-off-by: Petko Manolov <petkan@mip-labs.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15IMA: create machine owner and blacklist keyringsPetko Manolov3-0/+73
This option creates IMA MOK and blacklist keyrings. IMA MOK is an intermediate keyring that sits between .system and .ima keyrings, effectively forming a simple CA hierarchy. To successfully import a key into .ima_mok it must be signed by a key which CA is in .system keyring. On turn any key that needs to go in .ima keyring must be signed by CA in either .system or .ima_mok keyrings. IMA MOK is empty at kernel boot. IMA blacklist keyring contains all revoked IMA keys. It is consulted before any other keyring. If the search is successful the requested operation is rejected and error is returned to the caller. Signed-off-by: Petko Manolov <petkan@mip-labs.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>