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* Revert "evm: Translate user/group ids relative to s_user_ns when computing HMAC"Eric W. Biederman2016-12-021-2/+10
| | | | | | | | | | | | | | | | | 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>
* xattr: Add __vfs_{get,set,remove}xattr helpersAndreas Gruenbacher2016-10-071-3/+4
| | | | | | | | | | | 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>
* evm: Translate user/group ids relative to s_user_ns when computing HMACSeth Forshee2016-07-051-2/+2
| | | | | | | | | 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>
* evm: provide a function to set the EVM key from the kernelDmitry Kasatkin2015-12-151-7/+43
| | | | | | | | | | | | | | | | | | | | | | | A crypto HW kernel module can possibly initialize the EVM key from the kernel __init code to enable EVM before calling the 'init' process. This patch provides a function evm_set_key() to set the EVM key directly without using the KEY subsystem. Changes in v4: * kernel-doc style for evm_set_key Changes in v3: * error reporting moved to evm_set_key * EVM_INIT_HMAC moved to evm_set_key * added bitop to prevent key setting race Changes in v2: * use size_t for key size instead of signed int * provide EVM_MAX_KEY_SIZE macro in <linux/evm.h> * provide EVM_MIN_KEY_SIZE macro in <linux/evm.h> Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* evm: enable EVM when X509 certificate is loadedDmitry Kasatkin2015-12-151-0/+4
| | | | | | | | | | | | | | | | | | | | In order to enable EVM before starting the 'init' process, evm_initialized needs to be non-zero. Previously non-zero indicated that the HMAC key was loaded. When EVM loads the X509 before calling 'init', with this patch it is now possible to enable EVM to start signature based verification. This patch defines bits to enable EVM if a key of any type is loaded. Changes in v3: * print error message if key is not set Changes in v2: * EVM_STATE_KEY_SET replaced by EVM_INIT_HMAC * EVM_STATE_X509_SET replaced by EVM_INIT_X509 Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* KEYS: Merge the type-specific data with the payload dataDavid Howells2015-10-211-1/+1
| | | | | | | | | | | | | | | | | Merge the type-specific data with the payload data into one four-word chunk as it seems pointless to keep them separate. Use user_key_payload() for accessing the payloads of overloaded user-defined keys. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-cifs@vger.kernel.org cc: ecryptfs@vger.kernel.org cc: linux-ext4@vger.kernel.org cc: linux-f2fs-devel@lists.sourceforge.net cc: linux-nfs@vger.kernel.org cc: ceph-devel@vger.kernel.org cc: linux-ima-devel@lists.sourceforge.net
* VFS: security/: d_backing_inode() annotationsDavid Howells2015-04-151-2/+2
| | | | | | | | most of the ->d_inode uses there refer to the same inode IO would go to, i.e. d_backing_inode() Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* evm: replace HMAC version with attribute maskDmitry Kasatkin2014-06-121-1/+1
| | | | | | | | | | | | | | | | Using HMAC version limits the posibility to arbitrarily add new attributes such as SMACK64EXEC to the hmac calculation. This patch replaces hmac version with attribute mask. Desired attributes can be enabled with configuration parameter. It allows to build kernels which works with previously labeled filesystems. Currently supported attribute is 'fsuuid' which is equivalent of the former version 2. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2014-04-121-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "The first vfs pile, with deep apologies for being very late in this window. Assorted cleanups and fixes, plus a large preparatory part of iov_iter work. There's a lot more of that, but it'll probably go into the next merge window - it *does* shape up nicely, removes a lot of boilerplate, gets rid of locking inconsistencie between aio_write and splice_write and I hope to get Kent's direct-io rewrite merged into the same queue, but some of the stuff after this point is having (mostly trivial) conflicts with the things already merged into mainline and with some I want more testing. This one passes LTP and xfstests without regressions, in addition to usual beating. BTW, readahead02 in ltp syscalls testsuite has started giving failures since "mm/readahead.c: fix readahead failure for memoryless NUMA nodes and limit readahead pages" - might be a false positive, might be a real regression..." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) missing bits of "splice: fix racy pipe->buffers uses" cifs: fix the race in cifs_writev() ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure kill generic_file_buffered_write() ocfs2_file_aio_write(): switch to generic_perform_write() ceph_aio_write(): switch to generic_perform_write() xfs_file_buffered_aio_write(): switch to generic_perform_write() export generic_perform_write(), start getting rid of generic_file_buffer_write() generic_file_direct_write(): get rid of ppos argument btrfs_file_aio_write(): get rid of ppos kill the 5th argument of generic_file_buffered_write() kill the 4th argument of __generic_file_aio_write() lustre: don't open-code kernel_recvmsg() ocfs2: don't open-code kernel_recvmsg() drbd: don't open-code kernel_recvmsg() constify blk_rq_map_user_iov() and friends lustre: switch to kernel_sendmsg() ocfs2: don't open-code kernel_sendmsg() take iov_iter stuff to mm/iov_iter.c process_vm_access: tidy up a bit ...
| * get rid of pointless checks for NULL ->i_opAl Viro2014-04-011-1/+1
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | integrity: fix checkpatch errorsDmitry Kasatkin2014-03-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Between checkpatch changes (eg. sizeof) and inconsistencies between Lindent and checkpatch, unfixed checkpatch errors make it difficult to see new errors. This patch fixes them. Some lines with over 80 chars remained unchanged to improve code readability. The "extern" keyword is removed from internal evm.h to make it consistent with internal ima.h. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* | security: integrity: Use a more current logging styleJoe Perches2014-03-071-1/+3
|/ | | | | | | | | Convert printks to pr_<level>. Add pr_fmt. Remove embedded prefixes. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* Merge branch 'next' of ↵Linus Torvalds2013-02-211-0/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "This is basically a maintenance update for the TPM driver and EVM/IMA" Fix up conflicts in lib/digsig.c and security/integrity/ima/ima_main.c * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (45 commits) tpm/ibmvtpm: build only when IBM pseries is configured ima: digital signature verification using asymmetric keys ima: rename hash calculation functions ima: use new crypto_shash API instead of old crypto_hash ima: add policy support for file system uuid evm: add file system uuid to EVM hmac tpm_tis: check pnp_acpi_device return code char/tpm/tpm_i2c_stm_st33: drop temporary variable for return value char/tpm/tpm_i2c_stm_st33: remove dead assignment in tpm_st33_i2c_probe char/tpm/tpm_i2c_stm_st33: Remove __devexit attribute char/tpm/tpm_i2c_stm_st33: Don't use memcpy for one byte assignment tpm_i2c_stm_st33: removed unused variables/code TPM: Wait for TPM_ACCESS tpmRegValidSts to go high at startup tpm: Fix cancellation of TPM commands (interrupt mode) tpm: Fix cancellation of TPM commands (polling mode) tpm: Store TPM vendor ID TPM: Work around buggy TPMs that block during continue self test tpm_i2c_stm_st33: fix oops when i2c client is unavailable char/tpm: Use struct dev_pm_ops for power management TPM: STMicroelectronics ST33 I2C BUILD STUFF ...
| * evm: add file system uuid to EVM hmacDmitry Kasatkin2013-02-061-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | EVM uses the same key for all file systems to calculate the HMAC, making it possible to paste inodes from one file system on to another one, without EVM being able to detect it. To prevent such an attack, it is necessary to make the EVM HMAC file system specific. This patch uses the file system UUID, a file system unique identifier, to bind the EVM HMAC to the file system. The value inode->i_sb->s_uuid is used for the HMAC hash calculation, instead of using it for deriving the file system specific key. Initializing the key for every inode HMAC calculation is a bit more expensive operation than adding the uuid to the HMAC hash. Changing the HMAC calculation method or adding additional info to the calculation, requires existing EVM labeled file systems to be relabeled. This patch adds a Kconfig HMAC version option for backwards compatability. Changelog v1: - squash "hmac version setting" Changelog v0: - add missing Kconfig depends (Mimi) Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* | evm: checking if removexattr is not a NULLDmitry Kasatkin2013-01-221-2/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following lines of code produce a kernel oops. fd = socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); fchmod(fd, 0666); [ 139.922364] BUG: unable to handle kernel NULL pointer dereference at (null) [ 139.924982] IP: [< (null)>] (null) [ 139.924982] *pde = 00000000 [ 139.924982] Oops: 0000 [#5] SMP [ 139.924982] Modules linked in: fuse dm_crypt dm_mod i2c_piix4 serio_raw evdev binfmt_misc button [ 139.924982] Pid: 3070, comm: acpid Tainted: G D 3.8.0-rc2-kds+ #465 Bochs Bochs [ 139.924982] EIP: 0060:[<00000000>] EFLAGS: 00010246 CPU: 0 [ 139.924982] EIP is at 0x0 [ 139.924982] EAX: cf5ef000 EBX: cf5ef000 ECX: c143d600 EDX: c15225f2 [ 139.924982] ESI: cf4d2a1c EDI: cf4d2a1c EBP: cc02df10 ESP: cc02dee4 [ 139.924982] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 [ 139.924982] CR0: 80050033 CR2: 00000000 CR3: 0c059000 CR4: 000006d0 [ 139.924982] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [ 139.924982] DR6: ffff0ff0 DR7: 00000400 [ 139.924982] Process acpid (pid: 3070, ti=cc02c000 task=d7705340 task.ti=cc02c000) [ 139.924982] Stack: [ 139.924982] c1203c88 00000000 cc02def4 cf4d2a1c ae21eefa 471b60d5 1083c1ba c26a5940 [ 139.924982] e891fb5e 00000041 00000004 cc02df1c c1203964 00000000 cc02df4c c10e20c3 [ 139.924982] 00000002 00000000 00000000 22222222 c1ff2222 cf5ef000 00000000 d76efb08 [ 139.924982] Call Trace: [ 139.924982] [<c1203c88>] ? evm_update_evmxattr+0x5b/0x62 [ 139.924982] [<c1203964>] evm_inode_post_setattr+0x22/0x26 [ 139.924982] [<c10e20c3>] notify_change+0x25f/0x281 [ 139.924982] [<c10cbf56>] chmod_common+0x59/0x76 [ 139.924982] [<c10e27a1>] ? put_unused_fd+0x33/0x33 [ 139.924982] [<c10cca09>] sys_fchmod+0x39/0x5c [ 139.924982] [<c13f4f30>] syscall_call+0x7/0xb [ 139.924982] Code: Bad EIP value. This happens because sockets do not define the removexattr operation. Before removing the xattr, verify the removexattr function pointer is not NULL. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: stable@vger.kernel.org Signed-off-by: James Morris <james.l.morris@oracle.com>
* userns: Convert EVM to deal with kuids and kgids in it's hmac computationEric W. Biederman2012-09-211-2/+2
| | | | | | Cc: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* Merge branch 'next' into for-linusJames Morris2012-01-091-23/+53
|\ | | | | | | | | | | | | | | | | Conflicts: security/integrity/evm/evm_crypto.c Resolved upstream fix vs. next conflict manually. Signed-off-by: James Morris <jmorris@namei.org>
| * evm: prevent racing during tfm allocationDmitry Kasatkin2011-12-081-3/+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>
| * evm: key must be set once during initializationDmitry Kasatkin2011-12-081-7/+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>
| * evm: digital signature verification supportDmitry Kasatkin2011-11-091-17/+49
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* | evm: prevent racing during tfm allocationDmitry Kasatkin2011-12-201-0/+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>
* | evm: key must be set once during initializationDmitry Kasatkin2011-12-201-4/+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>
* evm: crypto hash replaced by shashDmitry Kasatkin2011-07-181-42/+52
| | | | | | | | | | | | 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>
* evm: add evm_inode_init_security to initialize new filesMimi Zohar2011-07-181-0/+20
| | | | | | | | | | | | | 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>
* evm: add support for different security.evm data typesDmitry Kasatkin2011-07-181-4/+7
| | | | | | | | | | | | | | | | | | | 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>
* evm: re-releaseMimi Zohar2011-07-181-0/+183
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>
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