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2019-03-01LSM: Update list of SECURITYFS users in KconfigPetr Vorel
Remove modules not using it (SELinux and SMACK aren't the only ones not using it). Signed-off-by: Petr Vorel <pvorel@suse.cz> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-01-25LSM: add SafeSetID module that gates setid callsMicah Morton
SafeSetID gates the setid family of syscalls to restrict UID/GID transitions from a given UID/GID to only those approved by a system-wide whitelist. These restrictions also prohibit the given UIDs/GIDs from obtaining auxiliary privileges associated with CAP_SET{U/G}ID, such as allowing a user to set up user namespace UID mappings. For now, only gating the set*uid family of syscalls is supported, with support for set*gid coming in a future patch set. Signed-off-by: Micah Morton <mortonm@chromium.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-01-08Yama: Initialize as ordered LSMKees Cook
This converts Yama from being a direct "minor" LSM into an ordered LSM. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
2019-01-08LoadPin: Initialize as ordered LSMKees Cook
This converts LoadPin from being a direct "minor" LSM into an ordered LSM. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
2019-01-08LSM: Introduce "lsm=" for boottime LSM selectionKees Cook
Provide a way to explicitly choose LSM initialization order via the new "lsm=" comma-separated list of LSMs. Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08LSM: Introduce CONFIG_LSMKees Cook
This provides a way to declare LSM initialization order via the new CONFIG_LSM. Currently only non-major LSMs are recognized. This will be expanded in future patches. Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-22treewide: surround Kconfig file paths with double quotesMasahiro Yamada
The Kconfig lexer supports special characters such as '.' and '/' in the parameter context. In my understanding, the reason is just to support bare file paths in the source statement. I do not see a good reason to complicate Kconfig for the room of ambiguity. The majority of code already surrounds file paths with double quotes, and it makes sense since file paths are constant string literals. Make it treewide consistent now. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Ingo Molnar <mingo@kernel.org>
2018-09-14Revert "x86/mm/legacy: Populate the user page-table with user pgd's"Joerg Roedel
This reverts commit 1f40a46cf47c12d93a5ad9dccd82bd36ff8f956a. It turned out that this patch is not sufficient to enable PTI on 32 bit systems with legacy 2-level page-tables. In this paging mode the huge-page PTEs are in the top-level page-table directory, where also the mirroring to the user-space page-table happens. So every huge PTE exits twice, in the kernel and in the user page-table. That means that accessed/dirty bits need to be fetched from two PTEs in this mode to be safe, but this is not trivial to implement because it needs changes to generic code just for the sake of enabling PTI with 32-bit legacy paging. As all systems that need PTI should support PAE anyway, remove support for PTI when 32-bit legacy paging is used. Fixes: 7757d607c6b3 ('x86/pti: Allow CONFIG_PAGE_TABLE_ISOLATION for x86_32') Reported-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: hpa@zytor.com Cc: linux-mm@kvack.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Link: https://lkml.kernel.org/r/1536922754-31379-1-git-send-email-joro@8bytes.org
2018-08-15Merge tag 'hardened-usercopy-v4.19-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardened usercopy updates from Kees Cook: "This cleans up a minor Kconfig issue and adds a kernel boot option for disabling hardened usercopy for distro users that may have corner-case performance issues (e.g. high bandwidth small-packet UDP traffic). Summary: - drop unneeded Kconfig "select BUG" (Kamal Mostafa) - add "hardened_usercopy=off" rare performance needs (Chris von Recklinghausen)" * tag 'hardened-usercopy-v4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: usercopy: Allow boot cmdline disabling of hardening usercopy: Do not select BUG with HARDENED_USERCOPY
2018-07-20x86/pti: Allow CONFIG_PAGE_TABLE_ISOLATION for x86_32Joerg Roedel
Allow PTI to be compiled on x86_32. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Pavel Machek <pavel@ucw.cz> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: linux-mm@kvack.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Waiman Long <llong@redhat.com> Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca> Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1531906876-13451-38-git-send-email-joro@8bytes.org
2018-07-02usercopy: Do not select BUG with HARDENED_USERCOPYKamal Mostafa
There is no need to "select BUG" when CONFIG_HARDENED_USERCOPY is enabled. The kernel thread will always die, regardless of the CONFIG_BUG. Signed-off-by: Kamal Mostafa <kamal@canonical.com> [kees: tweak commit log] Signed-off-by: Kees Cook <keescook@chromium.org>
2018-02-03Merge tag 'usercopy-v4.16-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardened usercopy whitelisting from Kees Cook: "Currently, hardened usercopy performs dynamic bounds checking on slab cache objects. This is good, but still leaves a lot of kernel memory available to be copied to/from userspace in the face of bugs. To further restrict what memory is available for copying, this creates a way to whitelist specific areas of a given slab cache object for copying to/from userspace, allowing much finer granularity of access control. Slab caches that are never exposed to userspace can declare no whitelist for their objects, thereby keeping them unavailable to userspace via dynamic copy operations. (Note, an implicit form of whitelisting is the use of constant sizes in usercopy operations and get_user()/put_user(); these bypass all hardened usercopy checks since these sizes cannot change at runtime.) This new check is WARN-by-default, so any mistakes can be found over the next several releases without breaking anyone's system. The series has roughly the following sections: - remove %p and improve reporting with offset - prepare infrastructure and whitelist kmalloc - update VFS subsystem with whitelists - update SCSI subsystem with whitelists - update network subsystem with whitelists - update process memory with whitelists - update per-architecture thread_struct with whitelists - update KVM with whitelists and fix ioctl bug - mark all other allocations as not whitelisted - update lkdtm for more sensible test overage" * tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (38 commits) lkdtm: Update usercopy tests for whitelisting usercopy: Restrict non-usercopy caches to size 0 kvm: x86: fix KVM_XEN_HVM_CONFIG ioctl kvm: whitelist struct kvm_vcpu_arch arm: Implement thread_struct whitelist for hardened usercopy arm64: Implement thread_struct whitelist for hardened usercopy x86: Implement thread_struct whitelist for hardened usercopy fork: Provide usercopy whitelisting for task_struct fork: Define usercopy region in thread_stack slab caches fork: Define usercopy region in mm_struct slab caches net: Restrict unwhitelisted proto caches to size 0 sctp: Copy struct sctp_sock.autoclose to userspace using put_user() sctp: Define usercopy region in SCTP proto slab cache caif: Define usercopy region in caif proto slab cache ip: Define usercopy region in IP proto slab cache net: Define usercopy region in struct proto slab cache scsi: Define usercopy region in scsi_sense_cache slab cache cifs: Define usercopy region in cifs_request slab cache vxfs: Define usercopy region in vxfs_inode slab cache ufs: Define usercopy region in ufs_inode_cache slab cache ...
2018-02-01Merge tag 'char-misc-4.16-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here is the big pull request for char/misc drivers for 4.16-rc1. There's a lot of stuff in here. Three new driver subsystems were added for various types of hardware busses: - siox - slimbus - soundwire as well as a new vboxguest subsystem for the VirtualBox hypervisor drivers. There's also big updates from the FPGA subsystem, lots of Android binder fixes, the usual handful of hyper-v updates, and lots of other smaller driver updates. All of these have been in linux-next for a long time, with no reported issues" * tag 'char-misc-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (155 commits) char: lp: use true or false for boolean values android: binder: use VM_ALLOC to get vm area android: binder: Use true and false for boolean values lkdtm: fix handle_irq_event symbol for INT_HW_IRQ_EN EISA: Delete error message for a failed memory allocation in eisa_probe() EISA: Whitespace cleanup misc: remove AVR32 dependencies virt: vbox: Add error mapping for VERR_INVALID_NAME and VERR_NO_MORE_FILES soundwire: Fix a signedness bug uio_hv_generic: fix new type mismatch warnings uio_hv_generic: fix type mismatch warnings auxdisplay: img-ascii-lcd: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE uio_hv_generic: add rescind support uio_hv_generic: check that host supports monitor page uio_hv_generic: create send and receive buffers uio: document uio_hv_generic regions doc: fix documentation about uio_hv_generic vmbus: add monitor_id and subchannel_id to sysfs per channel vmbus: fix ABI documentation uio_hv_generic: use ISR callback method ...
2018-01-15usercopy: Allow strict enforcement of whitelistsKees Cook
This introduces CONFIG_HARDENED_USERCOPY_FALLBACK to control the behavior of hardened usercopy whitelist violations. By default, whitelist violations will continue to WARN() so that any bad or missing usercopy whitelists can be discovered without being too disruptive. If this config is disabled at build time or a system is booted with "slab_common.usercopy_fallback=0", usercopy whitelists will BUG() instead of WARN(). This is useful for admins that want to use usercopy whitelists immediately. Suggested-by: Matthew Garrett <mjg59@google.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2018-01-14security/Kconfig: Correct the Documentation reference for PTIW. Trevor King
When the config option for PTI was added a reference to documentation was added as well. But the documentation did not exist at that point. The final documentation has a different file name. Fix it up to point to the proper file. Fixes: 385ce0ea ("x86/mm/pti: Add Kconfig") Signed-off-by: W. Trevor King <wking@tremily.us> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-mm@kvack.org Cc: linux-security-module@vger.kernel.org Cc: James Morris <james.l.morris@oracle.com> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/3009cc8ccbddcd897ec1e0cb6dda524929de0d14.1515799398.git.wking@tremily.us
2018-01-03x86/pti: Enable PTI by defaultThomas Gleixner
This really want's to be enabled by default. Users who know what they are doing can disable it either in the config or on the kernel command line. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
2018-01-02Merge 4.15-rc6 into char-misc-nextGreg Kroah-Hartman
We want the fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-23x86/mm/pti: Add KconfigDave Hansen
Finally allow CONFIG_PAGE_TABLE_ISOLATION to be enabled. PARAVIRT generally requires that the kernel not manage its own page tables. It also means that the hypervisor and kernel must agree wholeheartedly about what format the page tables are in and what they contain. PAGE_TABLE_ISOLATION, unfortunately, changes the rules and they can not be used together. I've seen conflicting feedback from maintainers lately about whether they want the Kconfig magic to go first or last in a patch series. It's going last here because the partially-applied series leads to kernels that can not boot in a bunch of cases. I did a run through the entire series with CONFIG_PAGE_TABLE_ISOLATION=y to look for build errors, though. [ tglx: Removed SMP and !PARAVIRT dependencies as they not longer exist ] Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-18/dev/mem: Add bounce buffer for copy-outKees Cook
As done for /proc/kcore in commit df04abfd181a ("fs/proc/kcore.c: Add bounce buffer for ktext data") this adds a bounce buffer when reading memory via /dev/mem. This is needed to allow kernel text memory to be read out when built with CONFIG_HARDENED_USERCOPY (which refuses to read out kernel text) and without CONFIG_STRICT_DEVMEM (which would have refused to read any RAM contents at all). Since this build configuration isn't common (most systems with CONFIG_HARDENED_USERCOPY also have CONFIG_STRICT_DEVMEM), this also tries to inform Kconfig about the recommended settings. This patch is modified from Brad Spengler/PaX Team's changes to /dev/mem code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Fixes: f5509cc18daa ("mm: Hardened usercopy") Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-12include/linux/string.h: add the option of fortified string.h functionsDaniel Micay
This adds support for compiling with a rough equivalent to the glibc _FORTIFY_SOURCE=1 feature, providing compile-time and runtime buffer overflow checks for string.h functions when the compiler determines the size of the source or destination buffer at compile-time. Unlike glibc, it covers buffer reads in addition to writes. GNU C __builtin_*_chk intrinsics are avoided because they would force a much more complex implementation. They aren't designed to detect read overflows and offer no real benefit when using an implementation based on inline checks. Inline checks don't add up to much code size and allow full use of the regular string intrinsics while avoiding the need for a bunch of _chk functions and per-arch assembly to avoid wrapper overhead. This detects various overflows at compile-time in various drivers and some non-x86 core kernel code. There will likely be issues caught in regular use at runtime too. Future improvements left out of initial implementation for simplicity, as it's all quite optional and can be done incrementally: * Some of the fortified string functions (strncpy, strcat), don't yet place a limit on reads from the source based on __builtin_object_size of the source buffer. * Extending coverage to more string functions like strlcat. * It should be possible to optionally use __builtin_object_size(x, 1) for some functions (C strings) to detect intra-object overflows (like glibc's _FORTIFY_SOURCE=2), but for now this takes the conservative approach to avoid likely compatibility issues. * The compile-time checks should be made available via a separate config option which can be enabled by default (or always enabled) once enough time has passed to get the issues it catches fixed. Kees said: "This is great to have. While it was out-of-tree code, it would have blocked at least CVE-2016-3858 from being exploitable (improper size argument to strlcpy()). I've sent a number of fixes for out-of-bounds-reads that this detected upstream already" [arnd@arndb.de: x86: fix fortified memcpy] Link: http://lkml.kernel.org/r/20170627150047.660360-1-arnd@arndb.de [keescook@chromium.org: avoid panic() in favor of BUG()] Link: http://lkml.kernel.org/r/20170626235122.GA25261@beast [keescook@chromium.org: move from -mm, add ARCH_HAS_FORTIFY_SOURCE, tweak Kconfig help] Link: http://lkml.kernel.org/r/20170526095404.20439-1-danielmicay@gmail.com Link: http://lkml.kernel.org/r/1497903987-21002-8-git-send-email-keescook@chromium.org Signed-off-by: Daniel Micay <danielmicay@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Daniel Axtens <dja@axtens.net> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-23IB/core: Enforce PKey security on QPsDaniel Jurgens
Add new LSM hooks to allocate and free security contexts and check for permission to access a PKey. Allocate and free a security context when creating and destroying a QP. This context is used for controlling access to PKeys. When a request is made to modify a QP that changes the port, PKey index, or alternate path, check that the QP has permission for the PKey in the PKey table index on the subnet prefix of the port. If the QP is shared make sure all handles to the QP also have access. Store which port and PKey index a QP is using. After the reset to init transition the user can modify the port, PKey index and alternate path independently. So port and PKey settings changes can be a merge of the previous settings and the new ones. In order to maintain access control if there are PKey table or subnet prefix change keep a list of all QPs are using each PKey index on each port. If a change occurs all QPs using that device and port must have access enforced for the new cache settings. These changes add a transaction to the QP modify process. Association with the old port and PKey index must be maintained if the modify fails, and must be removed if it succeeds. Association with the new port and PKey index must be established prior to the modify and removed if the modify fails. 1. When a QP is modified to a particular Port, PKey index or alternate path insert that QP into the appropriate lists. 2. Check permission to access the new settings. 3. If step 2 grants access attempt to modify the QP. 4a. If steps 2 and 3 succeed remove any prior associations. 4b. If ether fails remove the new setting associations. If a PKey table or subnet prefix changes walk the list of QPs and check that they have permission. If not send the QP to the error state and raise a fatal error event. If it's a shared QP make sure all the QPs that share the real_qp have permission as well. If the QP that owns a security structure is denied access the security structure is marked as such and the QP is added to an error_list. Once the moving the QP to error is complete the security structure mark is cleared. Maintaining the lists correctly turns QP destroy into a transaction. The hardware driver for the device frees the ib_qp structure, so while the destroy is in progress the ib_qp pointer in the ib_qp_security struct is undefined. When the destroy process begins the ib_qp_security structure is marked as destroying. This prevents any action from being taken on the QP pointer. After the QP is destroyed successfully it could still listed on an error_list wait for it to be processed by that flow before cleaning up the structure. If the destroy fails the QPs port and PKey settings are reinserted into the appropriate lists, the destroying flag is cleared, and access control is enforced, in case there were any cache changes during the destroy flow. To keep the security changes isolated a new file is used to hold security related functionality. Signed-off-by: Daniel Jurgens <danielj@mellanox.com> Acked-by: Doug Ledford <dledford@redhat.com> [PM: merge fixup in ib_verbs.h and uverbs_cmd.c] Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-22Sync to mainline for security submaintainers to work againstJames Morris
2017-05-15security: Grammar s/allocates/allocated/Geert Uytterhoeven
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-05-03Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "Highlights: IMA: - provide ">" and "<" operators for fowner/uid/euid rules KEYS: - add a system blacklist keyring - add KEYCTL_RESTRICT_KEYRING, exposes keyring link restriction functionality to userland via keyctl() LSM: - harden LSM API with __ro_after_init - add prlmit security hook, implement for SELinux - revive security_task_alloc hook TPM: - implement contextual TPM command 'spaces'" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (98 commits) tpm: Fix reference count to main device tpm_tis: convert to using locality callbacks tpm: fix handling of the TPM 2.0 event logs tpm_crb: remove a cruft constant keys: select CONFIG_CRYPTO when selecting DH / KDF apparmor: Make path_max parameter readonly apparmor: fix parameters so that the permission test is bypassed at boot apparmor: fix invalid reference to index variable of iterator line 836 apparmor: use SHASH_DESC_ON_STACK security/apparmor/lsm.c: set debug messages apparmor: fix boolreturn.cocci warnings Smack: Use GFP_KERNEL for smk_netlbl_mls(). smack: fix double free in smack_parse_opts_str() KEYS: add SP800-56A KDF support for DH KEYS: Keyring asymmetric key restrict method with chaining KEYS: Restrict asymmetric key linkage using a specific keychain KEYS: Add a lookup_restriction function for the asymmetric key type KEYS: Add KEYCTL_RESTRICT_KEYRING KEYS: Consistent ordering for __key_link_begin and restrict check KEYS: Add an optional lookup_restriction hook to key_type ...
2017-04-26HAVE_ARCH_HARDENED_USERCOPY is unconditional nowAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-06security: introduce CONFIG_SECURITY_WRITABLE_HOOKSJames Morris
Subsequent patches will add RO hardening to LSM hooks, however, SELinux still needs to be able to perform runtime disablement after init to handle architectures where init-time disablement via boot parameters is not feasible. Introduce a new kernel configuration parameter CONFIG_SECURITY_WRITABLE_HOOKS, and a helper macro __lsm_ro_after_init, to handle this case. Signed-off-by: James Morris <james.l.morris@oracle.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Kees Cook <keescook@chromium.org>
2017-01-19Introduce STATIC_USERMODEHELPER to mediate call_usermodehelper()Greg Kroah-Hartman
Some usermode helper applications are defined at kernel build time, while others can be changed at runtime. To provide a sane way to filter these, add a new kernel option "STATIC_USERMODEHELPER". This option routes all call_usermodehelper() calls through this binary, no matter what the caller wishes to have called. The new binary (by default set to /sbin/usermode-helper, but can be changed through the STATIC_USERMODEHELPER_PATH option) can properly filter the requested programs to be run by the kernel by looking at the first argument that is passed to it. All other options should then be passed onto the proper program if so desired. To disable all call_usermodehelper() calls by the kernel, set STATIC_USERMODEHELPER_PATH to an empty string. Thanks to Neil Brown for the idea of this feature. Cc: NeilBrown <neilb@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-07Merge tag 'usercopy-v4.8-rc6-part2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull more hardened usercopyfixes from Kees Cook: - force check_object_size() to be inline too - move page-spanning check behind a CONFIG since it's triggering false positives [ Changed the page-spanning config option to depend on EXPERT in the merge. That way it still gets build testing, and you can enable it if you want to, but is never enabled for "normal" configurations ] * tag 'usercopy-v4.8-rc6-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: usercopy: remove page-spanning test for now usercopy: force check_object_size() inline
2016-09-07usercopy: remove page-spanning test for nowKees Cook
A custom allocator without __GFP_COMP that copies to userspace has been found in vmw_execbuf_process[1], so this disables the page-span checker by placing it behind a CONFIG for future work where such things can be tracked down later. [1] https://bugzilla.redhat.com/show_bug.cgi?id=1373326 Reported-by: Vinson Lee <vlee@freedesktop.org> Fixes: f5509cc18daa ("mm: Hardened usercopy") Signed-off-by: Kees Cook <keescook@chromium.org>
2016-08-19Make the hardened user-copy code depend on having a hardened allocatorLinus Torvalds
The kernel test robot reported a usercopy failure in the new hardened sanity checks, due to a page-crossing copy of the FPU state into the task structure. This happened because the kernel test robot was testing with SLOB, which doesn't actually do the required book-keeping for slab allocations, and as a result the hardening code didn't realize that the task struct allocation was one single allocation - and the sanity checks fail. Since SLOB doesn't even claim to support hardening (and you really shouldn't use it), the straightforward solution is to just make the usercopy hardening code depend on the allocator supporting it. Reported-by: kernel test robot <xiaolong.ye@intel.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26mm: Hardened usercopyKees Cook
This is the start of porting PAX_USERCOPY into the mainline kernel. This is the first set of features, controlled by CONFIG_HARDENED_USERCOPY. The work is based on code by PaX Team and Brad Spengler, and an earlier port from Casey Schaufler. Additional non-slab page tests are from Rik van Riel. This patch contains the logic for validating several conditions when performing copy_to_user() and copy_from_user() on the kernel object being copied to/from: - address range doesn't wrap around - address range isn't NULL or zero-allocated (with a non-zero copy size) - if on the slab allocator: - object size must be less than or equal to copy size (when check is implemented in the allocator, which appear in subsequent patches) - otherwise, object must not span page allocations (excepting Reserved and CMA ranges) - if on the stack - object must not extend before/after the current process stack - object must be contained by a valid stack frame (when there is arch/build support for identifying stack frames) - object must not overlap with kernel text Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-21LSM: LoadPin for kernel file loading restrictionsKees Cook
This LSM enforces that kernel-loaded files (modules, firmware, etc) must all come from the same filesystem, with the expectation that such a filesystem is backed by a read-only device such as dm-verity or CDROM. This allows systems that have a verified and/or unchangeable filesystem to enforce module and firmware loading restrictions without needing to sign the files individually. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2015-07-28Yama: remove needless CONFIG_SECURITY_YAMA_STACKEDKees Cook
Now that minor LSMs can cleanly stack with major LSMs, remove the unneeded config for Yama to be made to explicitly stack. Just selecting the main Yama CONFIG will allow it to work, regardless of the major LSM. Since distros using Yama are already forcing it to stack, this is effectively a no-op change. Additionally add MAINTAINERS entry. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.l.morris@oracle.com>
2015-04-15kernel: conditionally support non-root users, groups and capabilitiesIulia Manda
There are a lot of embedded systems that run most or all of their functionality in init, running as root:root. For these systems, supporting multiple users is not necessary. This patch adds a new symbol, CONFIG_MULTIUSER, that makes support for non-root users, non-root groups, and capabilities optional. It is enabled under CONFIG_EXPERT menu. When this symbol is not defined, UID and GID are zero in any possible case and processes always have all capabilities. The following syscalls are compiled out: setuid, setregid, setgid, setreuid, setresuid, getresuid, setresgid, getresgid, setgroups, getgroups, setfsuid, setfsgid, capget, capset. Also, groups.c is compiled out completely. In kernel/capability.c, capable function was moved in order to avoid adding two ifdef blocks. This change saves about 25 KB on a defconfig build. The most minimal kernels have total text sizes in the high hundreds of kB rather than low MB. (The 25k goes down a bit with allnoconfig, but not that much. The kernel was booted in Qemu. All the common functionalities work. Adding users/groups is not possible, failing with -ENOSYS. Bloat-o-meter output: add/remove: 7/87 grow/shrink: 19/397 up/down: 1675/-26325 (-24650) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Iulia Manda <iulia.manda21@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-05security: select correct default LSM_MMAP_MIN_ADDR on arm on arm64Colin Cross
Binaries compiled for arm may run on arm64 if CONFIG_COMPAT is selected. Set LSM_MMAP_MIN_ADDR to 32768 if ARM64 && COMPAT to prevent selinux failures launching 32-bit static executables that are mapped at 0x8000. Signed-off-by: Colin Cross <ccross@android.com> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Eric Paris <eparis@redhat.com> Acked-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-05-11KEYS: Move the key config into security/keys/KconfigDavid Howells
Move the key config into security/keys/Kconfig as there are going to be a lot of key-related options. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Mimi Zohar <zohar@us.ibm.com>
2012-02-10security: Yama LSMKees Cook
This adds the Yama Linux Security Module to collect DAC security improvements (specifically just ptrace restrictions for now) that have existed in various forms over the years and have been carried outside the mainline kernel by other Linux distributions like Openwall and grsecurity. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: John Johansen <john.johansen@canonical.com> Signed-off-by: James Morris <jmorris@namei.org>
2011-09-14encrypted-keys: remove trusted-keys dependencyMimi Zohar
Encrypted keys are decrypted/encrypted using either a trusted-key or, for those systems without a TPM, a user-defined key. This patch removes the trusted-keys and TCG_TPM dependencies. Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-07-18integrity: move ima inode integrity data managementMimi Zohar
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>
2011-03-22security: select correct default LSM_MMAP_MIN_ADDR on ARM.Paul Gortmaker
The default for this is universally set to 64k, but the help says: For most ia64, ppc64 and x86 users with lots of address space a value of 65536 is reasonable and should cause no problems. On arm and other archs it should not be higher than 32768. The text is right, in that we are seeing selinux-enabled ARM targets that fail to launch /sbin/init because selinux blocks a memory map. So select the right value if we know we are building ARM. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: James Morris <jmorris@namei.org>
2010-11-29keys: add new key-type encryptedMimi Zohar
Define a new kernel key-type called 'encrypted'. Encrypted keys are kernel generated random numbers, which are encrypted/decrypted with a 'trusted' symmetric key. Encrypted keys are created/encrypted/decrypted in the kernel. Userspace only ever sees/stores encrypted blobs. Changelog: - bug fix: replaced master-key rcu based locking with semaphore (reported by David Howells) - Removed memset of crypto_shash_digest() digest output - Replaced verification of 'key-type:key-desc' using strcspn(), with one based on string constants. - Moved documentation to Documentation/keys-trusted-encrypted.txt - Replace hash with shash (based on comments by David Howells) - Make lengths/counts size_t where possible (based on comments by David Howells) Could not convert most lengths, as crypto expects 'unsigned int' (size_t: on 32 bit is defined as unsigned int, but on 64 bit is unsigned long) - Add 'const' where possible (based on comments by David Howells) - allocate derived_buf dynamically to support arbitrary length master key (fixed by Roberto Sassu) - wait until late_initcall for crypto libraries to be registered - cleanup security/Kconfig - Add missing 'update' keyword (reported/fixed by Roberto Sassu) - Free epayload on failure to create key (reported/fixed by Roberto Sassu) - Increase the data size limit (requested by Roberto Sassu) - Crypto return codes are always 0 on success and negative on failure, remove unnecessary tests. - Replaced kzalloc() with kmalloc() Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: David Safford <safford@watson.ibm.com> Reviewed-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: James Morris <jmorris@namei.org>
2010-11-29keys: add new trusted key-typeMimi Zohar
Define a new kernel key-type called 'trusted'. Trusted keys are random number symmetric keys, generated and RSA-sealed by the TPM. The TPM only unseals the keys, if the boot PCRs and other criteria match. Userspace can only ever see encrypted blobs. Based on suggestions by Jason Gunthorpe, several new options have been added to support additional usages. The new options are: migratable= designates that the key may/may not ever be updated (resealed under a new key, new pcrinfo or new auth.) pcrlock=n extends the designated PCR 'n' with a random value, so that a key sealed to that PCR may not be unsealed again until after a reboot. keyhandle= specifies the sealing/unsealing key handle. keyauth= specifies the sealing/unsealing key auth. blobauth= specifies the sealed data auth. Implementation of a kernel reserved locality for trusted keys will be investigated for a possible future extension. Changelog: - Updated and added examples to Documentation/keys-trusted-encrypted.txt - Moved generic TPM constants to include/linux/tpm_command.h (David Howell's suggestion.) - trusted_defined.c: replaced kzalloc with kmalloc, added pcrlock failure error handling, added const qualifiers where appropriate. - moved to late_initcall - updated from hash to shash (suggestion by David Howells) - reduced worst stack usage (tpm_seal) from 530 to 312 bytes - moved documentation to Documentation directory (suggestion by David Howells) - all the other code cleanups suggested by David Howells - Add pcrlock CAP_SYS_ADMIN dependency (based on comment by Jason Gunthorpe) - New options: migratable, pcrlock, keyhandle, keyauth, blobauth (based on discussions with Jason Gunthorpe) - Free payload on failure to create key(reported/fixed by Roberto Sassu) - Updated Kconfig and other descriptions (based on Serge Hallyn's suggestion) - Replaced kzalloc() with kmalloc() (reported by Serge Hallyn) Signed-off-by: David Safford <safford@watson.ibm.com> Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2010-11-12Restrict unprivileged access to kernel syslogDan Rosenberg
The kernel syslog contains debugging information that is often useful during exploitation of other vulnerabilities, such as kernel heap addresses. Rather than futilely attempt to sanitize hundreds (or thousands) of printk statements and simultaneously cripple useful debugging functionality, it is far simpler to create an option that prevents unprivileged users from reading the syslog. This patch, loosely based on grsecurity's GRKERNSEC_DMESG, creates the dmesg_restrict sysctl. When set to "0", the default, no restrictions are enforced. When set to "1", only users with CAP_SYS_ADMIN can read the kernel syslog via dmesg(8) or other mechanisms. [akpm@linux-foundation.org: explain the config option in kernel.txt] Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Eugene Teo <eugeneteo@kernel.org> Acked-by: Kees Cook <kees.cook@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-02AppArmor: Enable configuring and building of the AppArmor security moduleJohn Johansen
Kconfig and Makefiles to enable configuration and building of AppArmor. Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-11-24remove CONFIG_SECURITY_FILE_CAPABILITIES compile optionSerge E. Hallyn
As far as I know, all distros currently ship kernels with default CONFIG_SECURITY_FILE_CAPABILITIES=y. Since having the option on leaves a 'no_file_caps' option to boot without file capabilities, the main reason to keep the option is that turning it off saves you (on my s390x partition) 5k. In particular, vmlinux sizes came to: without patch fscaps=n: 53598392 without patch fscaps=y: 53603406 with this patch applied: 53603342 with the security-next tree. Against this we must weigh the fact that there is no simple way for userspace to figure out whether file capabilities are supported, while things like per-process securebits, capability bounding sets, and adding bits to pI if CAP_SETPCAP is in pE are not supported with SECURITY_FILE_CAPABILITIES=n, leaving a bit of a problem for applications wanting to know whether they can use them and/or why something failed. It also adds another subtly different set of semantics which we must maintain at the risk of severe security regressions. So this patch removes the SECURITY_FILE_CAPABILITIES compile option. It drops the kernel size by about 50k over the stock SECURITY_FILE_CAPABILITIES=y kernel, by removing the cap_limit_ptraced_target() function. Changelog: Nov 20: remove cap_limit_ptraced_target() as it's logic was ifndef'ed. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: Andrew G. Morgan" <morgan@kernel.org> Signed-off-by: James Morris <jmorris@namei.org>
2009-11-09Config option to set a default LSMJohn Johansen
The LSM currently requires setting a kernel parameter at boot to select a specific LSM. This adds a config option that allows specifying a default LSM that is used unless overridden with the security= kernel parameter. If the the config option is not set the current behavior of first LSM to register is used. Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-10-20security: remove root_plugJames Morris
Remove the root_plug example LSM code. It's unmaintained and increasingly broken in various ways. Made at the 2009 Kernel Summit in Tokyo! Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: James Morris <jmorris@namei.org>
2009-09-02Merge commit 'v2.6.31-rc8' into x86/txtIngo Molnar
Conflicts: arch/x86/kernel/reboot.c security/Kconfig Merge reason: resolve the conflicts, bump up from rc3 to rc8. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-01x86, intel_txt: clean up the impact on generic code, unbreak non-x86Shane Wang
Move tboot.h from asm to linux to fix the build errors of intel_txt patch on non-X86 platforms. Remove the tboot code from generic code init/main.c and kernel/cpu.c. Signed-off-by: Shane Wang <shane.wang@intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-08-19security: Fix prompt for LSM_MMAP_MIN_ADDRAndreas Schwab
Fix prompt for LSM_MMAP_MIN_ADDR. (Verbs are cool!) Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>