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2012-01-19ima: fix cred sparse warningMimi Zohar1-1/+2
Fix ima_policy.c sparse "warning: dereference of noderef expression" message, by accessing cred->uid using current_cred(). Changelog v1: - Change __cred to just cred (based on David Howell's comment) Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2012-01-18Merge branch 'for-linus' of ↵Linus Torvalds3-5/+5
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: integrity: digital signature config option name change lib: Removed MPILIB, MPILIB_EXTRA, and SIGNATURE prompts lib: MPILIB Kconfig description update lib: digital signature dependency fix lib: digital signature config option name change encrypted-keys: fix rcu and sparse messages keys: fix trusted/encrypted keys sparse rcu_assign_pointer messages KEYS: Add missing smp_rmb() primitives to the keyring search code TOMOYO: Accept \000 as a valid character. security: update MAINTAINERS file with new git repo
2012-01-18integrity: digital signature config option name changeDmitry Kasatkin3-4/+4
Similar to SIGNATURE, rename INTEGRITY_DIGSIG to INTEGRITY_SIGNATURE. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Signed-off-by: James Morris <jmorris@namei.org>
2012-01-18lib: digital signature config option name changeDmitry Kasatkin1-1/+1
It was reported that DIGSIG is confusing name for digital signature module. It was suggested to rename DIGSIG to SIGNATURE. Requested-by: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Signed-off-by: James Morris <jmorris@namei.org>
2012-01-18audit: treat s_id as an untrusted stringKees Cook1-3/+5
The use of s_id should go through the untrusted string path, just to be extra careful. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2012-01-09Merge branch 'next' into for-linusJames Morris9-43/+244
Conflicts: security/integrity/evm/evm_crypto.c Resolved upstream fix vs. next conflict manually. Signed-off-by: James Morris <jmorris@namei.org>
2011-12-20evm: prevent racing during tfm allocationDmitry Kasatkin1-0/+9
There is a small chance of racing during tfm allocation. This patch fixes it. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Acked-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2011-12-20evm: key must be set once during initializationDmitry Kasatkin1-4/+6
On multi-core systems, setting of the key before every caclculation, causes invalid HMAC calculation for other tfm users, because internal state (ipad, opad) can be invalid before set key call returns. It needs to be set only once during initialization. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Acked-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2011-12-20ima: fix invalid memory referenceRoberto Sassu1-5/+11
Don't free a valid measurement entry on TPM PCR extend failure. Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Cc: stable@vger.kernel.org
2011-12-20ima: free duplicate measurement memoryRoberto Sassu2-2/+3
Info about new measurements are cached in the iint for performance. When the inode is flushed from cache, the associated iint is flushed as well. Subsequent access to the inode will cause the inode to be re-measured and will attempt to add a duplicate entry to the measurement list. This patch frees the duplicate measurement memory, fixing a memory leak. Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Cc: stable@vger.kernel.org
2011-12-08evm: prevent racing during tfm allocationDmitry Kasatkin1-3/+11
There is a small chance of racing during tfm allocation. This patch fixes it. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Acked-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2011-12-08evm: key must be set once during initializationDmitry Kasatkin1-7/+8
On multi-core systems, setting of the key before every caclculation, causes invalid HMAC calculation for other tfm users, because internal state (ipad, opad) can be invalid before set key call returns. It needs to be set only once during initialization. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Acked-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2011-11-22digsig: build dependency fixDmitry Kasatkin1-1/+1
Fix build errors by adding Kconfig dependency on KEYS. CRYPTO dependency removed. CC security/integrity/digsig.o security/integrity/digsig.c: In function ?integrity_digsig_verify?: security/integrity/digsig.c:38:4: error: implicit declaration of function ?request_key? security/integrity/digsig.c:38:17: error: ?key_type_keyring? undeclared (first use in this function) security/integrity/digsig.c:38:17: note: each undeclared identifier is reported only once for each function it appears in make[2]: *** [security/integrity/digsig.o] Error 1 Reported-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Signed-off-by: James Morris <jmorris@namei.org>
2011-11-09evm: digital signature verification supportDmitry Kasatkin3-30/+142
This patch adds support for digital signature verification to EVM. With this feature file metadata can be protected using digital signature instead of an HMAC. When building an image, which has to be flashed to different devices, an HMAC cannot be used to sign file metadata, because the HMAC key should be different on every device. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Acked-by: Mimi Zohar <zohar@us.ibm.com>
2011-11-09integrity: digital signature verification using multiple keyringsDmitry Kasatkin4-0/+84
Define separate keyrings for each of the different use cases - evm, ima, and modules. Using different keyrings improves search performance, and also allows "locking" specific keyring to prevent adding new keys. This is useful for evm and module keyrings, when keys are usually only added from initramfs. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2011-11-02Merge branch 'for-linus' of git://github.com/richardweinberger/linuxLinus Torvalds1-1/+1
* 'for-linus' of git://github.com/richardweinberger/linux: (90 commits) um: fix ubd cow size um: Fix kmalloc argument order in um/vdso/vma.c um: switch to use of drivers/Kconfig UserModeLinux-HOWTO.txt: fix a typo UserModeLinux-HOWTO.txt: remove ^H characters um: we need sys/user.h only on i386 um: merge delay_{32,64}.c um: distribute exports to where exported stuff is defined um: kill system-um.h um: generic ftrace.h will do... um: segment.h is x86-only and needed only there um: asm/pda.h is not needed anymore um: hw_irq.h can go generic as well um: switch to generic-y um: clean Kconfig up a bit um: a couple of missing dependencies... um: kill useless argument of free_chan() and free_one_chan() um: unify ptrace_user.h um: unify KSTK_... um: fix gcov build breakage ...
2011-11-02um: switch to use of drivers/KconfigAl Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2011-09-14evm: clean verification statusDmitry Kasatkin1-0/+1
When allocating from slab, initialization is done the first time in init_once() and subsequently on free. Because evm_status was not re-initialized on free, evm_verify_hmac() skipped verifications. This patch re-initializes evm_status. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-09-14evm: permit mode bits to be updatedMimi Zohar1-17/+13
Before permitting 'security.evm' to be updated, 'security.evm' must exist and be valid. In the case that there are no existing EVM protected xattrs, it is safe for posix acls to update the mode bits. To differentiate between no 'security.evm' xattr and no xattrs used to calculate 'security.evm', this patch defines INTEGRITY_NOXATTR. Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-09-14evm: posix acls modify i_modeMimi Zohar3-5/+46
The posix xattr acls are 'system' prefixed, which normally would not affect security.evm. An interesting side affect of writing posix xattr acls is their modifying of the i_mode, which is included in security.evm. This patch updates security.evm when posix xattr acls are written. Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-09-14evm: limit verifying current security.evm integrityMimi Zohar1-34/+24
evm_protect_xattr unnecessarily validates the current security.evm integrity, before updating non-evm protected extended attributes and other file metadata. This patch limits validating the current security.evm integrity to evm protected metadata. Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-09-14evm: remove TCG_TPM dependencyMimi Zohar1-2/+1
All tristates selected by EVM(boolean) are forced to be builtin, except in the TCG_TPM(tristate) dependency case. Arnaud Lacombe summarizes the Kconfig bug as, "So it would seem direct dependency state influence the state of reverse dependencies.." For a detailed explanation, refer to Arnaud Lacombe's posting http://lkml.org/lkml/2011/8/23/498. With the "encrypted-keys: remove trusted-keys dependency" patch, EVM can now be built without a dependency on TCG_TPM. The trusted-keys dependency requires trusted-keys to either be builtin or not selected. This dependency will prevent the boolean/tristate mismatch from occuring. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>, Randy Dunlap <rdunlap@xenotimenet> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-09-10ima: sparse fix: include linux/ima.h in ima_main.cJames Morris1-0/+1
Fixes sparse warnings: security/integrity/ima/ima_main.c:105:6: warning: symbol 'ima_file_free' was not declared. Should it be static? security/integrity/ima/ima_main.c:167:5: warning: symbol 'ima_file_mmap' was not declared. Should it be static? security/integrity/ima/ima_main.c:192:5: warning: symbol 'ima_bprm_check' was not declared. Should it be static? security/integrity/ima/ima_main.c:211:5: warning: symbol 'ima_file_check' was not declared. Should it be static? Signed-off-by: James Morris <jmorris@namei.org>
2011-09-10ima: sparse fix: make ima_open_policy staticJames Morris1-1/+1
Fixes sparse warning: security/integrity/ima/ima_fs.c:290:5: warning: symbol 'ima_open_policy' was not declared. Should it be static? Signed-off-by: James Morris <jmorris@namei.org>
2011-09-10integrity: sparse fix: move iint_initialized to integrity.hJames Morris2-1/+3
Sparse fix: move iint_initialized to integrity.h Signed-off-by: James Morris <jmorris@namei.org>
2011-08-18evm: add Kconfig TCG_TPM dependencyMimi Zohar1-1/+1
Although the EVM encrypted-key should be encrypted/decrypted using a trusted-key, a user-defined key could be used instead. When using a user- defined key, a TCG_TPM dependency should not be required. Unfortunately, the encrypted-key code needs to be refactored a bit in order to remove this dependency. This patch adds the TCG_TPM dependency. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>, Randy Dunlap <rdunlap@xenotimenet> Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2011-08-11evm: fix evm_inode_init_security return codeMimi Zohar1-1/+1
evm_inode_init_security() should return 0, when EVM is not enabled. (Returning an error is a remnant of evm_inode_post_init_security.) Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2011-08-09EVM: ensure trusted and encypted key symbols are available to EVMJames Morris1-1/+3
Select trusted and encrypted keys if EVM is selected, to ensure the requisite symbols are available. Otherwise, these can be selected as modules while EVM is static, leading to a kernel build failure. Signed-off-by: James Morris <jmorris@namei.org>
2011-08-09Merge branch 'next-evm' of ↵James Morris16-199/+1022
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/ima-2.6 into next Conflicts: fs/attr.c Resolve conflict manually. Signed-off-by: James Morris <jmorris@namei.org>
2011-07-26ima: fmode_t misspelled as mode_t...Al Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-18evm: add evm_inode_setattr to prevent updating an invalid security.evmMimi Zohar1-0/+15
Permit changing of security.evm only when valid, unless in fixmode. Reported-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-07-18evm: permit only valid security.evm xattrs to be updatedMimi Zohar1-14/+63
In addition to requiring CAP_SYS_ADMIN permission to modify/delete security.evm, prohibit invalid security.evm xattrs from changing, unless in fixmode. This patch prevents inadvertent 'fixing' of security.evm to reflect offline modifications. Changelog v7: - rename boot paramater 'evm_mode' to 'evm' Reported-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-07-18evm: replace hmac_status with evm_statusDmitry Kasatkin3-9/+9
We will use digital signatures in addtion to hmac. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-07-18evm: evm_verify_hmac must not return INTEGRITY_UNKNOWNDmitry Kasatkin1-6/+5
If EVM is not supported or enabled, evm_verify_hmac() returns INTEGRITY_UNKNOWN, which ima_appraise_measurement() ignores and sets the appraisal status based solely on the security.ima verification. evm_verify_hmac() also returns INTEGRITY_UNKNOWN for other failures, such as temporary failures like -ENOMEM, resulting in possible attack vectors. This patch changes the default return code for temporary/unexpected failures, like -ENOMEM, from INTEGRITY_UNKNOWN to INTEGRITY_FAIL, making evm_verify_hmac() fail safe. As a result, failures need to be re-evaluated in order to catch both temporary errors, such as the -ENOMEM, as well as errors that have been resolved in fix mode. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-07-18evm: additional parameter to pass integrity cache entry 'iint'Dmitry Kasatkin1-10/+8
Additional iint parameter allows to skip lookup in the cache. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2011-07-18evm: crypto hash replaced by shashDmitry Kasatkin3-45/+57
Using shash is more efficient, because the algorithm is allocated only once. Only the descriptor to store the hash state needs to be allocated for every operation. Changelog v6: - check for crypto_shash_setkey failure Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2011-07-18evm: add evm_inode_init_security to initialize new filesMimi Zohar3-0/+61
Initialize 'security.evm' for new files. Changelog v7: - renamed evm_inode_post_init_security to evm_inode_init_security - moved struct xattr definition to earlier patch - allocate xattr name Changelog v6: - Use 'struct evm_ima_xattr_data' Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-07-18security: imbed evm calls in security hooksMimi Zohar1-0/+1
Imbed the evm calls evm_inode_setxattr(), evm_inode_post_setxattr(), evm_inode_removexattr() in the security hooks. evm_inode_setxattr() protects security.evm xattr. evm_inode_post_setxattr() and evm_inode_removexattr() updates the hmac associated with an inode. (Assumes an LSM module protects the setting/removing of xattr.) Changelog: - Don't define evm_verifyxattr(), unless CONFIG_INTEGRITY is enabled. - xattr_name is a 'const', value is 'void *' Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
2011-07-18evm: add support for different security.evm data typesDmitry Kasatkin3-9/+23
EVM protects a file's security extended attributes(xattrs) against integrity attacks. The current patchset maintains an HMAC-sha1 value across the security xattrs, storing the value as the extended attribute 'security.evm'. We anticipate other methods for protecting the security extended attributes. This patch reserves the first byte of 'security.evm' as a place holder for the type of method. Changelog v6: - move evm_ima_xattr_type definition to security/integrity/integrity.h - defined a structure for the EVM xattr called evm_ima_xattr_data (based on Serge Hallyn's suggestion) - removed unnecessary memset Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com> Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
2011-07-18evm: re-releaseMimi Zohar10-1/+632
EVM protects a file's security extended attributes(xattrs) against integrity attacks. This patchset provides the framework and an initial method. The initial method maintains an HMAC-sha1 value across the security extended attributes, storing the HMAC value as the extended attribute 'security.evm'. Other methods of validating the integrity of a file's metadata will be posted separately (eg. EVM-digital-signatures). While this patchset does authenticate the security xattrs, and cryptographically binds them to the inode, coming extensions will bind other directory and inode metadata for more complete protection. To help simplify the review and upstreaming process, each extension will be posted separately (eg. IMA-appraisal, IMA-appraisal-directory). For a general overview of the proposed Linux integrity subsystem, refer to Dave Safford's whitepaper: http://downloads.sf.net/project/linux-ima/linux-ima/Integrity_overview.pdf. EVM depends on the Kernel Key Retention System to provide it with a trusted/encrypted key for the HMAC-sha1 operation. The key is loaded onto the root's keyring using keyctl. Until EVM receives notification that the key has been successfully loaded onto the keyring (echo 1 > <securityfs>/evm), EVM can not create or validate the 'security.evm' xattr, but returns INTEGRITY_UNKNOWN. Loading the key and signaling EVM should be done as early as possible. Normally this is done in the initramfs, which has already been measured as part of the trusted boot. For more information on creating and loading existing trusted/encrypted keys, refer to Documentation/keys-trusted-encrypted.txt. A sample dracut patch, which loads the trusted/encrypted key and enables EVM, is available from http://linux-ima.sourceforge.net/#EVM. Based on the LSMs enabled, the set of EVM protected security xattrs is defined at compile. EVM adds the following three calls to the existing security hooks: evm_inode_setxattr(), evm_inode_post_setxattr(), and evm_inode_removexattr. To initialize and update the 'security.evm' extended attribute, EVM defines three calls: evm_inode_post_init(), evm_inode_post_setattr() and evm_inode_post_removexattr() hooks. To verify the integrity of a security xattr, EVM exports evm_verifyxattr(). Changelog v7: - Fixed URL in EVM ABI documentation Changelog v6: (based on Serge Hallyn's review) - fix URL in patch description - remove evm_hmac_size definition - use SHA1_DIGEST_SIZE (removed both MAX_DIGEST_SIZE and evm_hmac_size) - moved linux include before other includes - test for crypto_hash_setkey failure - fail earlier for invalid key - clear entire encrypted key, even on failure - check xattr name length before comparing xattr names Changelog: - locking based on i_mutex, remove evm_mutex - using trusted/encrypted keys for storing the EVM key used in the HMAC-sha1 operation. - replaced crypto hash with shash (Dmitry Kasatkin) - support for additional methods of verifying the security xattrs (Dmitry Kasatkin) - iint not allocated for all regular files, but only for those appraised - Use cap_sys_admin in lieu of cap_mac_admin - Use __vfs_setxattr_noperm(), without permission checks, from EVM Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
2011-07-18integrity: move ima inode integrity data managementMimi Zohar10-199/+242
Move the inode integrity data(iint) management up to the integrity directory in order to share the iint among the different integrity models. Changelog: - don't define MAX_DIGEST_SIZE - rename several globally visible 'ima_' prefixed functions, structs, locks, etc to 'integrity_' - replace '20' with SHA1_DIGEST_SIZE - reflect location change in appropriate Kconfig and Makefiles - remove unnecessary initialization of iint_initialized to 0 - rebased on current ima_iint.c - define integrity_iint_store/lock as static There should be no other functional changes. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
2011-02-24ima: remove unnecessary call to ima_must_measureMimi Zohar3-15/+7
The original ima_must_measure() function based its results on cached iint information, which required an iint be allocated for all files. Currently, an iint is allocated only for files in policy. As a result, for those files in policy, ima_must_measure() is now called twice: once to determine if the inode is in the measurement policy and, the second time, to determine if it needs to be measured/re-measured. The second call to ima_must_measure() unnecessarily checks to see if the file is in policy. As we already know the file is in policy, this patch removes the second unnecessary call to ima_must_measure(), removes the vestige iint parameter, and just checks the iint directly to determine if the inode has been measured or needs to be measured/re-measured. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com>
2011-02-10IMA: remove IMA imbalance checkingMimi Zohar2-104/+4
Now that i_readcount is maintained by the VFS layer, remove the imbalance checking in IMA. Cleans up the IMA code nicely. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com>
2011-02-10IMA: maintain i_readcount in the VFS layerMimi Zohar2-19/+8
ima_counts_get() updated the readcount and invalidated the PCR, as necessary. Only update the i_readcount in the VFS layer. Move the PCR invalidation checks to ima_file_check(), where it belongs. Maintaining the i_readcount in the VFS layer, will allow other subsystems to use i_readcount. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com>
2011-02-10IMA: convert i_readcount to atomicMimi Zohar2-8/+10
Convert the inode's i_readcount from an unsigned int to atomic. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com>
2011-01-04ima: fix add LSM rule bugMimi Zohar1-0/+2
If security_filter_rule_init() doesn't return a rule, then not everything is as fine as the return code implies. This bug only occurs when the LSM (eg. SELinux) is disabled at runtime. Adding an empty LSM rule causes ima_match_rules() to always succeed, ignoring any remaining rules. default IMA TCB policy: # PROC_SUPER_MAGIC dont_measure fsmagic=0x9fa0 # SYSFS_MAGIC dont_measure fsmagic=0x62656572 # DEBUGFS_MAGIC dont_measure fsmagic=0x64626720 # TMPFS_MAGIC dont_measure fsmagic=0x01021994 # SECURITYFS_MAGIC dont_measure fsmagic=0x73636673 < LSM specific rule > dont_measure obj_type=var_log_t measure func=BPRM_CHECK measure func=FILE_MMAP mask=MAY_EXEC measure func=FILE_CHECK mask=MAY_READ uid=0 Thus without the patch, with the boot parameters 'tcb selinux=0', adding the above 'dont_measure obj_type=var_log_t' rule to the default IMA TCB measurement policy, would result in nothing being measured. The patch prevents the default TCB policy from being replaced. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Cc: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Cc: David Safford <safford@watson.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26IMA: fix the ToMToU logicEric Paris1-5/+6
Current logic looks like this: rc = ima_must_measure(NULL, inode, MAY_READ, FILE_CHECK); if (rc < 0) goto out; if (mode & FMODE_WRITE) { if (inode->i_readcount) send_tomtou = true; goto out; } if (atomic_read(&inode->i_writecount) > 0) send_writers = true; Lets assume we have a policy which states that all files opened for read by root must be measured. Lets assume the file has permissions 777. Lets assume that root has the given file open for read. Lets assume that a non-root process opens the file write. The non-root process will get to ima_counts_get() and will check the ima_must_measure(). Since it is not supposed to measure it will goto out. We should check the i_readcount no matter what since we might be causing a ToMToU voilation! This is close to correct, but still not quite perfect. The situation could have been that root, which was interested in the mesurement opened and closed the file and another process which is not interested in the measurement is the one holding the i_readcount ATM. This is just overly strict on ToMToU violations, which is better than not strict enough... Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26IMA: explicit IMA i_flag to remove global lock on inode_deleteEric Paris2-5/+12
Currently for every removed inode IMA must take a global lock and search the IMA rbtree looking for an associated integrity structure. Instead we explicitly mark an inode when we add an integrity structure so we only have to take the global lock and do the removal if it exists. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26IMA: drop refcnt from ima_iint_cache since it isn't neededEric Paris3-30/+19
Since finding a struct ima_iint_cache requires a valid struct inode, and the struct ima_iint_cache is supposed to have the same lifetime as a struct inode (technically they die together but don't need to be created at the same time) we don't have to worry about the ima_iint_cache outliving or dieing before the inode. So the refcnt isn't useful. Just get rid of it and free the structure when the inode is freed. Signed-off-by: Eric Paris <eapris@redhat.com> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26IMA: only allocate iint when neededEric Paris1-30/+64
IMA always allocates an integrity structure to hold information about every inode, but only needed this structure to track the number of readers and writers currently accessing a given inode. Since that information was moved into struct inode instead of the integrity struct this patch stops allocating the integrity stucture until it is needed. Thus greatly reducing memory usage. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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