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2018-03-25ima: Fallback to the builtin hash algorithmPetr Vorel
IMA requires having it's hash algorithm be compiled-in due to it's early use. The default IMA algorithm is protected by Kconfig to be compiled-in. The ima_hash kernel parameter allows to choose the hash algorithm. When the specified algorithm is not available or available as a module, IMA initialization fails, which leads to a kernel panic (mknodat syscall calls ima_post_path_mknod()). Therefore as fallback we force IMA to use the default builtin Kconfig hash algorithm. Fixed crash: $ grep CONFIG_CRYPTO_MD4 .config CONFIG_CRYPTO_MD4=m [ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-4.12.14-2.3-default root=UUID=74ae8202-9ca7-4e39-813b-22287ec52f7a video=1024x768-16 plymouth.ignore-serial-consoles console=ttyS0 console=tty resume=/dev/disk/by-path/pci-0000:00:07.0-part3 splash=silent showopts ima_hash=md4 ... [ 1.545190] ima: Can not allocate md4 (reason: -2) ... [ 2.610120] BUG: unable to handle kernel NULL pointer dereference at (null) [ 2.611903] IP: ima_match_policy+0x23/0x390 [ 2.612967] PGD 0 P4D 0 [ 2.613080] Oops: 0000 [#1] SMP [ 2.613080] Modules linked in: autofs4 [ 2.613080] Supported: Yes [ 2.613080] CPU: 0 PID: 1 Comm: systemd Not tainted 4.12.14-2.3-default #1 [ 2.613080] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 [ 2.613080] task: ffff88003e2d0040 task.stack: ffffc90000190000 [ 2.613080] RIP: 0010:ima_match_policy+0x23/0x390 [ 2.613080] RSP: 0018:ffffc90000193e88 EFLAGS: 00010296 [ 2.613080] RAX: 0000000000000000 RBX: 000000000000000c RCX: 0000000000000004 [ 2.613080] RDX: 0000000000000010 RSI: 0000000000000001 RDI: ffff880037071728 [ 2.613080] RBP: 0000000000008000 R08: 0000000000000000 R09: 0000000000000000 [ 2.613080] R10: 0000000000000008 R11: 61c8864680b583eb R12: 00005580ff10086f [ 2.613080] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000008000 [ 2.613080] FS: 00007f5c1da08940(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000 [ 2.613080] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2.613080] CR2: 0000000000000000 CR3: 0000000037002000 CR4: 00000000003406f0 [ 2.613080] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 2.613080] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 2.613080] Call Trace: [ 2.613080] ? shmem_mknod+0xbf/0xd0 [ 2.613080] ima_post_path_mknod+0x1c/0x40 [ 2.613080] SyS_mknod+0x210/0x220 [ 2.613080] entry_SYSCALL_64_fastpath+0x1a/0xa5 [ 2.613080] RIP: 0033:0x7f5c1bfde570 [ 2.613080] RSP: 002b:00007ffde1c90dc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 [ 2.613080] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5c1bfde570 [ 2.613080] RDX: 0000000000000000 RSI: 0000000000008000 RDI: 00005580ff10086f [ 2.613080] RBP: 00007ffde1c91040 R08: 00005580ff10086f R09: 0000000000000000 [ 2.613080] R10: 0000000000104000 R11: 0000000000000246 R12: 00005580ffb99660 [ 2.613080] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002 [ 2.613080] Code: 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 57 41 56 44 8d 14 09 41 55 41 54 55 53 44 89 d3 09 cb 48 83 ec 38 48 8b 05 c5 03 29 01 <4c> 8b 20 4c 39 e0 0f 84 d7 01 00 00 4c 89 44 24 08 89 54 24 20 [ 2.613080] RIP: ima_match_policy+0x23/0x390 RSP: ffffc90000193e88 [ 2.613080] CR2: 0000000000000000 [ 2.613080] ---[ end trace 9a9f0a8a73079f6a ]--- [ 2.673052] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 [ 2.673052] [ 2.675337] Kernel Offset: disabled [ 2.676405] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 Signed-off-by: Petr Vorel <pvorel@suse.cz> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-25ima: Add smackfs to the default appraise/measure listMartin Townsend
This is required to use SMACK and IMA/EVM together. Add it to the default nomeasure/noappraise list like other pseudo filesystems. Signed-off-by: Martin Townsend <mtownsend1973@gmail.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-25evm: check for remount ro in progress before writingSascha Hauer
EVM might update the evm xattr while the VFS performs a remount to readonly mode. This is not properly checked for, additionally check the s_readonly_remount superblock flag before writing. The bug can for example be observed with UBIFS. UBIFS checks the free space on the device before and after a remount. With EVM enabled the free space sometimes differs between both checks. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-25ima: Improvements in ima_appraise_measurement()Thiago Jung Bauermann
Replace nested ifs in the EVM xattr verification logic with a switch statement, making the code easier to understand. Also, add comments to the if statements in the out section and constify the cause variable. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Acked-by: Serge Hallyn <serge@hallyn.com>
2018-03-25ima: Simplify ima_eventsig_init()Thiago Jung Bauermann
The "goto out" statement doesn't have any purpose since there's no cleanup to be done when returning early, so remove it. This also makes the rc variable unnecessary so remove it as well. Also, the xattr_len and fmt variables are redundant so remove them as well. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-25integrity: Remove unused macro IMA_ACTION_RULE_FLAGSThiago Jung Bauermann
This macro isn't used anymore since commit 0d73a55208e9 ("ima: re-introduce own integrity cache lock"), so remove it. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-25ima: drop vla in ima_audit_measurement()Tycho Andersen
In keeping with the directive to get rid of VLAs [1], let's drop the VLA from ima_audit_measurement(). We need to adjust the return type of ima_audit_measurement, because now this function can fail if an allocation fails. [1]: https://lkml.org/lkml/2018/3/7/621 v2: just use audit_log_format instead of doing a second allocation v3: ignore failures in ima_audit_measurement() Signed-off-by: Tycho Andersen <tycho@tycho.ws> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-25ima: Fix Kconfig to select TPM 2.0 CRB interfaceJiandi An
TPM_CRB driver provides TPM CRB 2.0 support. If it is built as a module, the TPM chip is registered after IMA init. tpm_pcr_read() in IMA fails and displays the following message even though eventually there is a TPM chip on the system. ima: No TPM chip found, activating TPM-bypass! (rc=-19) Fix IMA Kconfig to select TPM_CRB so TPM_CRB driver is built in the kernel and initializes before IMA. Signed-off-by: Jiandi An <anjiandi@codeaurora.org> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-23evm: Constify *integrity_status_msg[]Hernán Gonzalez
There is no gain from doing this except for some self-documenting. Signed-off-by: Hernán Gonzalez <hernan@vanguardiasur.com.ar> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-23evm: Move evm_hmac and evm_hash from evm_main.c to evm_crypto.cHernán Gonzalez
These variables are not used where they are was defined. There is no point in declaring them there as extern. Move and constify them, saving 2 bytes. Function old new delta init_desc 273 271 -2 Total: Before=2112094, After=2112092, chg -0.00% Signed-off-by: Hernán Gonzalez <hernan@vanguardiasur.com.ar> Tested-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-23ima: fail signature verification based on policyMimi Zohar
This patch addresses the fuse privileged mounted filesystems in environments which are unwilling to accept the risk of trusting the signature verification and want to always fail safe, but are for example using a pre-built kernel. This patch defines a new builtin policy named "fail_securely", which can be specified on the boot command line as an argument to "ima_policy=". Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: Dongsu Park <dongsu@kinvolk.io> Cc: Alban Crequy <alban@kinvolk.io> Acked-by: Serge Hallyn <serge@hallyn.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-03-23ima: clear IMA_HASHMimi Zohar
The IMA_APPRAISE and IMA_HASH policies overlap. Clear IMA_HASH properly. Fixes: da1b0029f527 ("ima: support new "hash" and "dont_hash" policy actions") Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-23ima: re-evaluate files on privileged mounted filesystemsMimi Zohar
This patch addresses the fuse privileged mounted filesystems in a "secure" environment, with a correctly enforced security policy, which is willing to assume the inherent risk of specific fuse filesystems that are well defined and properly implemented. As there is no way for the kernel to detect file changes, the kernel ignores the cached file integrity results and re-measures, re-appraises, and re-audits the file. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: Dongsu Park <dongsu@kinvolk.io> Cc: Alban Crequy <alban@kinvolk.io> Acked-by: Serge Hallyn <serge@hallyn.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-03-23ima: fail file signature verification on non-init mounted filesystemsMimi Zohar
FUSE can be mounted by unprivileged users either today with fusermount installed with setuid, or soon with the upcoming patches to allow FUSE mounts in a non-init user namespace. This patch addresses the new unprivileged non-init mounted filesystems, which are untrusted, by failing the signature verification. This patch defines two new flags SB_I_IMA_UNVERIFIABLE_SIGNATURE and SB_I_UNTRUSTED_MOUNTER. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: Dongsu Park <dongsu@kinvolk.io> Cc: Alban Crequy <alban@kinvolk.io> Acked-by: Serge Hallyn <serge@hallyn.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-03-23IMA: Support using new creds in appraisal policyMatthew Garrett
The existing BPRM_CHECK functionality in IMA validates against the credentials of the existing process, not any new credentials that the child process may transition to. Add an additional CREDS_CHECK target and refactor IMA to pass the appropriate creds structure. In ima_bprm_check(), check with both the existing process credentials and the credentials that will be committed when the new process is started. This will not change behaviour unless the system policy is extended to include CREDS_CHECK targets - BPRM_CHECK will continue to check the same credentials that it did previously. After this patch, an IMA policy rule along the lines of: measure func=CREDS_CHECK subj_type=unconfined_t will trigger if a process is executed and runs as unconfined_t, ignoring the context of the parent process. This is in contrast to: measure func=BPRM_CHECK subj_type=unconfined_t which will trigger if the process that calls exec() is already executing in unconfined_t, ignoring the context that the child process executes into. Signed-off-by: Matthew Garrett <mjg59@google.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Changelog: - initialize ima_creds_status
2018-02-22integrity/security: fix digsig.c build error with header fileRandy Dunlap
security/integrity/digsig.c has build errors on some $ARCH due to a missing header file, so add it. security/integrity/digsig.c:146:2: error: implicit declaration of function 'vfree' [-Werror=implicit-function-declaration] Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: linux-integrity@vger.kernel.org Link: http://kisskb.ellerman.id.au/kisskb/head/13396/ Signed-off-by: James Morris <james.morris@microsoft.com>
2018-02-07Merge tag 'iversion-v4.16-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux Pull inode->i_version cleanup from Jeff Layton: "Goffredo went ahead and sent a patch to rename this function, and reverse its sense, as we discussed last week. The patch is very straightforward and I figure it's probably best to go ahead and merge this to get the API as settled as possible" * tag 'iversion-v4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux: iversion: Rename make inode_cmp_iversion{+raw} to inode_eq_iversion{+raw}
2018-02-02ima: re-initialize iint->atomic_flagsMimi Zohar
Intermittently security.ima is not being written for new files. This patch re-initializes the new slab iint->atomic_flags field before freeing it. Fixes: commit 0d73a55208e9 ("ima: re-introduce own integrity cache lock") Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2018-02-01iversion: Rename make inode_cmp_iversion{+raw} to inode_eq_iversion{+raw}Goffredo Baroncelli
The function inode_cmp_iversion{+raw} is counter-intuitive, because it returns true when the counters are different and false when these are equal. Rename it to inode_eq_iversion{+raw}, which will returns true when the counters are equal and false otherwise. Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it> Signed-off-by: Jeff Layton <jlayton@redhat.com>
2018-01-31Merge branch 'next-tpm' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull tpm updates from James Morris: - reduce polling delays in tpm_tis - support retrieving TPM 2.0 Event Log through EFI before ExitBootServices - replace tpm-rng.c with a hwrng device managed by the driver for each TPM device - TPM resource manager synthesizes TPM_RC_COMMAND_CODE response instead of returning -EINVAL for unknown TPM commands. This makes user space more sound. - CLKRUN fixes: * Keep #CLKRUN disable through the entier TPM command/response flow * Check whether #CLKRUN is enabled before disabling and enabling it again because enabling it breaks PS/2 devices on a system where it is disabled * 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: tpm: remove unused variables tpm: remove unused data fields from I2C and OF device ID tables tpm: only attempt to disable the LPC CLKRUN if is already enabled tpm: follow coding style for variable declaration in tpm_tis_core_init() tpm: delete the TPM_TIS_CLK_ENABLE flag tpm: Update MAINTAINERS for Jason Gunthorpe tpm: Keep CLKRUN enabled throughout the duration of transmit_cmd() tpm_tis: Move ilb_base_addr to tpm_tis_data tpm2-cmd: allow more attempts for selftest execution tpm: return a TPM_RC_COMMAND_CODE response if command is not implemented tpm: Move Linux RNG connection to hwrng tpm: use struct tpm_chip for tpm_chip_find_get() tpm: parse TPM event logs based on EFI table efi: call get_event_log before ExitBootServices tpm: add event log format version tpm: rename event log provider files tpm: move tpm_eventlog.h outside of drivers folder tpm: use tpm_msleep() value as max delay tpm: reduce tpm polling delay in tpm_tis_core tpm: move wait_for_tpm_stat() to respective driver files
2018-01-31Merge branch 'next-integrity' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull integrity updates from James Morris: "This contains a mixture of bug fixes, code cleanup, and new functionality. Of note is the integrity cache locking fix, file change detection, and support for a new EVM portable and immutable signature type. The re-introduction of the integrity cache lock (iint) fixes the problem of attempting to take the i_rwsem shared a second time, when it was previously taken exclusively. Defining atomic flags resolves the original iint/i_rwsem circular locking - accessing the file data vs. modifying the file metadata. Although it fixes the O_DIRECT problem as well, a subsequent patch is needed to remove the explicit O_DIRECT prevention. For performance reasons, detecting when a file has changed and needs to be re-measured, re-appraised, and/or re-audited, was limited to after the last writer has closed, and only if the file data has changed. Detecting file change is based on i_version. For filesystems that do not support i_version, remote filesystems, or userspace filesystems, the file was measured, appraised and/or audited once and never re-evaluated. Now local filesystems, which do not support i_version or are not mounted with the i_version option, assume the file has changed and are required to re-evaluate the file. This change does not address detecting file change on remote or userspace filesystems. Unlike file data signatures, which can be included and distributed in software packages (eg. rpm, deb), the existing EVM signature, which protects the file metadata, could not be included in software packages, as it includes file system specific information (eg. i_ino, possibly the UUID). This pull request defines a new EVM portable and immutable file metadata signature format, which can be included in software packages" * 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: ima/policy: fix parsing of fsuuid ima: Use i_version only when filesystem supports it integrity: remove unneeded initializations in integrity_iint_cache entries ima: log message to module appraisal error ima: pass filename to ima_rdwr_violation_check() ima: Fix line continuation format ima: support new "hash" and "dont_hash" policy actions ima: re-introduce own integrity cache lock EVM: Add support for portable signature format EVM: Allow userland to permit modification of EVM-protected metadata ima: relax requiring a file signature for new files with zero length
2018-01-29IMA: switch IMA over to new i_version APIJeff Layton
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2018-01-18ima/policy: fix parsing of fsuuidMike Rapoport
The switch to uuid_t invereted the logic of verfication that &entry->fsuuid is zero during parsing of "fsuuid=" rule. Instead of making sure the &entry->fsuuid field is not attempted to be overwritten, we bail out for perfectly correct rule. Fixes: 787d8c530af7 ("ima/policy: switch to use uuid_t") Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-01-08tpm: use struct tpm_chip for tpm_chip_find_get()Jarkko Sakkinen
Device number (the character device index) is not a stable identifier for a TPM chip. That is the reason why every call site passes TPM_ANY_NUM to tpm_chip_find_get(). This commit changes the API in a way that instead a struct tpm_chip instance is given and NULL means the default chip. In addition, this commit refines the documentation to be up to date with the implementation. Suggested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> (@chip_num -> @chip part) Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@ziepe.ca> Tested-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
2017-12-18ima: Use i_version only when filesystem supports itSascha Hauer
i_version is only supported by a filesystem when the SB_I_VERSION flag is set. This patch tests for the SB_I_VERSION flag before using i_version. If we can't use i_version to detect a file change then we must assume the file has changed in the last_writer path and remeasure it. On filesystems without i_version support IMA used to measure a file only once and didn't detect any changes to a file. With this patch IMA now works properly on these filesystems. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-18integrity: remove unneeded initializations in integrity_iint_cache entriesJeff Layton
The init_once routine memsets the whole object to 0, and then explicitly sets some of the fields to 0 again. Just remove the explicit initializations. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-18ima: log message to module appraisal errorBruno E. O. Meneguele
Simple but useful message log to the user in case of module appraise is forced and fails due to the lack of file descriptor, that might be caused by kmod calls to compressed modules. Signed-off-by: Bruno E. O. Meneguele <brdeoliv@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-18ima: pass filename to ima_rdwr_violation_check()Roberto Sassu
ima_rdwr_violation_check() retrieves the full path of a measured file by calling ima_d_path(). If process_measurement() calls this function, it reuses the pointer and passes it to the functions to measure/appraise/audit an accessed file. After commit bc15ed663e7e ("ima: fix ima_d_path() possible race with rename"), ima_d_path() first tries to retrieve the full path by calling d_absolute_path() and, if there is an error, copies the dentry name to the buffer passed as argument. However, ima_rdwr_violation_check() passes to ima_d_path() the pointer of a local variable. process_measurement() might be reusing the pointer to an area in the stack which may have been already overwritten after ima_rdwr_violation_check() returned. Correct this issue by passing to ima_rdwr_violation_check() the pointer of a buffer declared in process_measurement(). Fixes: bc15ed663e7e ("ima: fix ima_d_path() possible race with rename") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-18ima: Fix line continuation formatJoe Perches
Line continuations with excess spacing causes unexpected output. Based on commit 6f76b6fcaa60 ("CodingStyle: Document the exception of not splitting user-visible strings, for grepping") recommendation. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-18ima: support new "hash" and "dont_hash" policy actionsMimi Zohar
The builtin ima_appraise_tcb policy, which is specified on the boot command line, can be replaced with a custom policy, normally early in the boot process. Custom policies can be more restrictive in some ways, like requiring file signatures, but can be less restrictive in other ways, like not appraising mutable files. With a less restrictive policy in place, files in the builtin policy might not be hashed and labeled with a security.ima hash. On reboot, files which should be labeled in the ima_appraise_tcb are not labeled, possibly preventing the system from booting properly. To resolve this problem, this patch extends the existing IMA policy actions "measure", "dont_measure", "appraise", "dont_appraise", and "audit" with "hash" and "dont_hash". The new "hash" action will write the file hash as security.ima, but without requiring the file to be appraised as well. For example, the builtin ima_appraise_tcb policy includes the rule, "appraise fowner=0". Adding the "hash fowner=0" rule to a custom policy, will cause the needed file hashes to be calculated and written as security.ima xattrs. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
2017-12-13ima: Use i_version only when filesystem supports itSascha Hauer
i_version is only supported by a filesystem when the SB_I_VERSION flag is set. This patch tests for the SB_I_VERSION flag before using i_version. If we can't use i_version to detect a file change then we must assume the file has changed in the last_writer path and remeasure it. On filesystems without i_version support IMA used to measure a file only once and didn't detect any changes to a file. With this patch IMA now works properly on these filesystems. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-12-11ima: re-introduce own integrity cache lockDmitry Kasatkin
Before IMA appraisal was introduced, IMA was using own integrity cache lock along with i_mutex. process_measurement and ima_file_free took the iint->mutex first and then the i_mutex, while setxattr, chmod and chown took the locks in reverse order. To resolve the potential deadlock, i_mutex was moved to protect entire IMA functionality and the redundant iint->mutex was eliminated. Solution was based on the assumption that filesystem code does not take i_mutex further. But when file is opened with O_DIRECT flag, direct-io implementation takes i_mutex and produces deadlock. Furthermore, certain other filesystem operations, such as llseek, also take i_mutex. More recently some filesystems have replaced their filesystem specific lock with the global i_rwsem to read a file. As a result, when IMA attempts to calculate the file hash, reading the file attempts to take the i_rwsem again. To resolve O_DIRECT related deadlock problem, this patch re-introduces iint->mutex. But to eliminate the original chmod() related deadlock problem, this patch eliminates the requirement for chmod hooks to take the iint->mutex by introducing additional atomic iint->attr_flags to indicate calling of the hooks. The allowed locking order is to take the iint->mutex first and then the i_rwsem. Original flags were cleared in chmod(), setxattr() or removwxattr() hooks and tested when file was closed or opened again. New atomic flags are set or cleared in those hooks and tested to clear iint->flags on close or on open. Atomic flags are following: * IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown, chgrp) and file attributes have changed. On file open, it causes IMA to clear iint->flags to re-evaluate policy and perform IMA functions again. * IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called and extended attributes have changed. On file open, it causes IMA to clear iint->flags IMA_DONE_MASK to re-appraise. * IMA_UPDATE_XATTR - indicates that security.ima needs to be updated. It is cleared if file policy changes and no update is needed. * IMA_DIGSIG - indicates that file security.ima has signature and file security.ima must not update to file has on file close. * IMA_MUST_MEASURE - indicates the file is in the measurement policy. Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in the VFS inode instead") Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-11EVM: Add support for portable signature formatMatthew Garrett
The EVM signature includes the inode number and (optionally) the filesystem UUID, making it impractical to ship EVM signatures in packages. This patch adds a new portable format intended to allow distributions to include EVM signatures. It is identical to the existing format but hardcodes the inode and generation numbers to 0 and does not include the filesystem UUID even if the kernel is configured to do so. Removing the inode means that the metadata and signature from one file could be copied to another file without invalidating it. This is avoided by ensuring that an IMA xattr is present during EVM validation. Portable signatures are intended to be immutable - ie, they will never be transformed into HMACs. Based on earlier work by Dmitry Kasatkin and Mikhail Kurinnoi. Signed-off-by: Matthew Garrett <mjg59@google.com> Cc: Dmitry Kasatkin <dmitry.kasatkin@huawei.com> Cc: Mikhail Kurinnoi <viewizard@viewizard.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-11EVM: Allow userland to permit modification of EVM-protected metadataMatthew Garrett
When EVM is enabled it forbids modification of metadata protected by EVM unless there is already a valid EVM signature. If any modification is made, the kernel will then generate a new EVM HMAC. However, this does not map well on use cases which use only asymmetric EVM signatures, as in this scenario the kernel is unable to generate new signatures. This patch extends the /sys/kernel/security/evm interface to allow userland to request that modification of these xattrs be permitted. This is only permitted if no keys have already been loaded. In this configuration, modifying the metadata will invalidate the EVM appraisal on the file in question. This allows packaging systems to write out new files, set the relevant extended attributes and then move them into place. There's also some refactoring of the use of evm_initialized in order to avoid heading down codepaths that assume there's a key available. Signed-off-by: Matthew Garrett <mjg59@google.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-11ima: relax requiring a file signature for new files with zero lengthMimi Zohar
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>
2017-11-20ima: do not update security.ima if appraisal status is not INTEGRITY_PASSRoberto Sassu
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. Cc: stable@vger.kernel.org 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>
2017-11-14Merge branch 'linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto updates from Herbert Xu: "Here is the crypto update for 4.15: API: - Disambiguate EBUSY when queueing crypto request by adding ENOSPC. This change touches code outside the crypto API. - Reset settings when empty string is written to rng_current. Algorithms: - Add OSCCA SM3 secure hash. Drivers: - Remove old mv_cesa driver (replaced by marvell/cesa). - Enable rfc3686/ecb/cfb/ofb AES in crypto4xx. - Add ccm/gcm AES in crypto4xx. - Add support for BCM7278 in iproc-rng200. - Add hash support on Exynos in s5p-sss. - Fix fallback-induced error in vmx. - Fix output IV in atmel-aes. - Fix empty GCM hash in mediatek. Others: - Fix DoS potential in lib/mpi. - Fix potential out-of-order issues with padata" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (162 commits) lib/mpi: call cond_resched() from mpi_powm() loop crypto: stm32/hash - Fix return issue on update crypto: dh - Remove pointless checks for NULL 'p' and 'g' crypto: qat - Clean up error handling in qat_dh_set_secret() crypto: dh - Don't permit 'key' or 'g' size longer than 'p' crypto: dh - Don't permit 'p' to be 0 crypto: dh - Fix double free of ctx->p hwrng: iproc-rng200 - Add support for BCM7278 dt-bindings: rng: Document BCM7278 RNG200 compatible crypto: chcr - Replace _manual_ swap with swap macro crypto: marvell - Add a NULL entry at the end of mv_cesa_plat_id_table[] hwrng: virtio - Virtio RNG devices need to be re-registered after suspend/resume crypto: atmel - remove empty functions crypto: ecdh - remove empty exit() MAINTAINERS: update maintainer for qat crypto: caam - remove unused param of ctx_map_to_sec4_sg() crypto: caam - remove unneeded edesc zeroization crypto: atmel-aes - Reset the controller before each use crypto: atmel-aes - properly set IV after {en,de}crypt hwrng: core - Reset user selected rng by writing "" to rng_current ...
2017-11-13Merge branch 'next-integrity' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem integrity updates from James Morris: "There is a mixture of bug fixes, code cleanup, preparatory code for new functionality and new functionality. Commit 26ddabfe96bb ("evm: enable EVM when X509 certificate is loaded") enabled EVM without loading a symmetric key, but was limited to defining the x509 certificate pathname at build. Included in this set of patches is the ability of enabling EVM, without loading the EVM symmetric key, from userspace. New is the ability to prevent the loading of an EVM symmetric key." * 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: ima: Remove redundant conditional operator ima: Fix bool initialization/comparison ima: check signature enforcement against cmdline param instead of CONFIG module: export module signature enforcement status ima: fix hash algorithm initialization EVM: Only complain about a missing HMAC key once EVM: Allow userspace to signal an RSA key has been loaded EVM: Include security.apparmor in EVM measurements ima: call ima_file_free() prior to calling fasync integrity: use kernel_read_file_from_path() to read x509 certs ima: always measure and audit files in policy ima: don't remove the securityfs policy file vfs: fix mounting a filesystem with i_version
2017-11-08ima: Remove redundant conditional operatorThiago Jung Bauermann
A non-zero value is converted to 1 when assigned to a bool variable, so the conditional operator in is_ima_appraise_enabled is redundant. The value of a comparison operator is either 1 or 0 so the conditional operator in ima_inode_setxattr is redundant as well. Confirmed that the patch is correct by comparing the object file from before and after the patch. They are identical. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08ima: Fix bool initialization/comparisonThomas Meyer
Bool initializations should use true and false. Bool tests don't need comparisons. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08ima: check signature enforcement against cmdline param instead of CONFIGBruno E. O. Meneguele
When the user requests MODULE_CHECK policy and its kernel is compiled with CONFIG_MODULE_SIG_FORCE not set, all modules would not load, just those loaded in initram time. One option the user would have would be set a kernel cmdline param (module.sig_enforce) to true, but the IMA module check code doesn't rely on this value, it checks just CONFIG_MODULE_SIG_FORCE. This patch solves this problem checking for the exported value of module.sig_enforce cmdline param intead of CONFIG_MODULE_SIG_FORCE, which holds the effective value (CONFIG || param). Signed-off-by: Bruno E. O. Meneguele <brdeoliv@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08ima: fix hash algorithm initializationBoshi Wang
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>
2017-11-08EVM: Only complain about a missing HMAC key onceMatthew Garrett
A system can validate EVM digital signatures without requiring an HMAC key, but every EVM validation will generate a kernel error. Change this so we only generate an error once. Signed-off-by: Matthew Garrett <mjg59@google.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08EVM: Allow userspace to signal an RSA key has been loadedMatthew Garrett
EVM will only perform validation once a key has been loaded. This key may either be a symmetric trusted key (for HMAC validation and creation) or the public half of an asymmetric key (for digital signature validation). The /sys/kernel/security/evm interface allows userland to signal that a symmetric key has been loaded, but does not allow userland to signal that an asymmetric public key has been loaded. This patch extends the interface to permit userspace to pass a bitmask of loaded key types. It also allows userspace to block loading of a symmetric key in order to avoid a compromised system from being able to load an additional key type later. Signed-off-by: Matthew Garrett <mjg59@google.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08EVM: Include security.apparmor in EVM measurementsMatthew Garrett
Apparmor will be gaining support for security.apparmor labels, and it would be helpful to include these in EVM validation now so appropriate signatures can be generated even before full support is merged. Signed-off-by: Matthew Garrett <mjg59@google.com> Acked-by: John Johansen <John.johansen@canonical.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08integrity: use kernel_read_file_from_path() to read x509 certsChristoph Hellwig
The CONFIG_IMA_LOAD_X509 and CONFIG_EVM_LOAD_X509 options permit loading x509 signed certificates onto the trusted keyrings without verifying the x509 certificate file's signature. This patch replaces the call to the integrity_read_file() specific function with the common kernel_read_file_from_path() function. To avoid verifying the file signature, this patch defines READING_X509_CERTFICATE. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08ima: always measure and audit files in policyMimi Zohar
All files matching a "measure" rule must be included in the IMA measurement list, even when the file hash cannot be calculated. Similarly, all files matching an "audit" rule must be audited, even when the file hash can not be calculated. The file data hash field contained in the IMA measurement list template data will contain 0's instead of the actual file hash digest. Note: In general, adding, deleting or in anyway changing which files are included in the IMA measurement list is not a good idea, as it might result in not being able to unseal trusted keys sealed to a specific TPM PCR value. This patch not only adds file measurements that were not previously measured, but specifies that the file hash value for these files will be 0's. As the IMA measurement list ordering is not consistent from one boot to the next, it is unlikely that anyone is sealing keys based on the IMA measurement list. Remote attestation servers should be able to process these new measurement records, but might complain about these unknown records. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Reviewed-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2017-11-08ima: don't remove the securityfs policy fileMimi Zohar
The securityfs policy file is removed unless additional rules can be appended to the IMA policy (CONFIG_IMA_WRITE_POLICY), regardless as to whether the policy is configured so that it can be displayed. This patch changes this behavior, removing the securityfs policy file, only if CONFIG_IMA_READ_POLICY is also not enabled. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-03ima: move to generic async completionGilad Ben-Yossef
ima starts several async crypto ops and waits for their completions. Move it over to generic code doing the same. Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>