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6040e57658
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>
198 lines
6.7 KiB
Plaintext
198 lines
6.7 KiB
Plaintext
#
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# Security configuration
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#
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menu "Security options"
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source security/keys/Kconfig
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config SECURITY_DMESG_RESTRICT
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bool "Restrict unprivileged access to the kernel syslog"
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default n
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help
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This enforces restrictions on unprivileged users reading the kernel
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syslog via dmesg(8).
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If this option is not selected, no restrictions will be enforced
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unless the dmesg_restrict sysctl is explicitly set to (1).
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If you are unsure how to answer this question, answer N.
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config SECURITY
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bool "Enable different security models"
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depends on SYSFS
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depends on MULTIUSER
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help
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This allows you to choose different security modules to be
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configured into your kernel.
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If this option is not selected, the default Linux security
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model will be used.
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If you are unsure how to answer this question, answer N.
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config SECURITYFS
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bool "Enable the securityfs filesystem"
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help
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This will build the securityfs filesystem. It is currently used by
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the TPM bios character driver and IMA, an integrity provider. It is
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not used by SELinux or SMACK.
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If you are unsure how to answer this question, answer N.
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config SECURITY_NETWORK
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bool "Socket and Networking Security Hooks"
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depends on SECURITY
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help
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This enables the socket and networking security hooks.
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If enabled, a security module can use these hooks to
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implement socket and networking access controls.
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If you are unsure how to answer this question, answer N.
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config SECURITY_NETWORK_XFRM
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bool "XFRM (IPSec) Networking Security Hooks"
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depends on XFRM && SECURITY_NETWORK
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help
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This enables the XFRM (IPSec) networking security hooks.
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If enabled, a security module can use these hooks to
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implement per-packet access controls based on labels
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derived from IPSec policy. Non-IPSec communications are
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designated as unlabelled, and only sockets authorized
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to communicate unlabelled data can send without using
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IPSec.
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If you are unsure how to answer this question, answer N.
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config SECURITY_PATH
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bool "Security hooks for pathname based access control"
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depends on SECURITY
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help
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This enables the security hooks for pathname based access control.
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If enabled, a security module can use these hooks to
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implement pathname based access controls.
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If you are unsure how to answer this question, answer N.
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config INTEL_TXT
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bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
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depends on HAVE_INTEL_TXT
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help
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This option enables support for booting the kernel with the
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Trusted Boot (tboot) module. This will utilize
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Intel(R) Trusted Execution Technology to perform a measured launch
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of the kernel. If the system does not support Intel(R) TXT, this
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will have no effect.
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Intel TXT will provide higher assurance of system configuration and
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initial state as well as data reset protection. This is used to
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create a robust initial kernel measurement and verification, which
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helps to ensure that kernel security mechanisms are functioning
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correctly. This level of protection requires a root of trust outside
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of the kernel itself.
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Intel TXT also helps solve real end user concerns about having
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confidence that their hardware is running the VMM or kernel that
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it was configured with, especially since they may be responsible for
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providing such assurances to VMs and services running on it.
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See <http://www.intel.com/technology/security/> for more information
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about Intel(R) TXT.
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See <http://tboot.sourceforge.net> for more information about tboot.
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See Documentation/intel_txt.txt for a description of how to enable
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Intel TXT support in a kernel boot.
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If you are unsure as to whether this is required, answer N.
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config LSM_MMAP_MIN_ADDR
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int "Low address space for LSM to protect from user allocation"
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depends on SECURITY && SECURITY_SELINUX
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default 32768 if ARM || (ARM64 && COMPAT)
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default 65536
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help
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This is the portion of low virtual memory which should be protected
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from userspace allocation. Keeping a user from writing to low pages
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can help reduce the impact of kernel NULL pointer bugs.
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For most ia64, ppc64 and x86 users with lots of address space
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a value of 65536 is reasonable and should cause no problems.
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On arm and other archs it should not be higher than 32768.
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Programs which use vm86 functionality or have some need to map
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this low address space will need the permission specific to the
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systems running LSM.
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config HAVE_HARDENED_USERCOPY_ALLOCATOR
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bool
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help
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The heap allocator implements __check_heap_object() for
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validating memory ranges against heap object sizes in
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support of CONFIG_HARDENED_USERCOPY.
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config HAVE_ARCH_HARDENED_USERCOPY
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bool
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help
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The architecture supports CONFIG_HARDENED_USERCOPY by
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calling check_object_size() just before performing the
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userspace copies in the low level implementation of
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copy_to_user() and copy_from_user().
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config HARDENED_USERCOPY
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bool "Harden memory copies between kernel and userspace"
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depends on HAVE_ARCH_HARDENED_USERCOPY
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depends on HAVE_HARDENED_USERCOPY_ALLOCATOR
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select BUG
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help
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This option checks for obviously wrong memory regions when
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copying memory to/from the kernel (via copy_to_user() and
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copy_from_user() functions) by rejecting memory ranges that
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are larger than the specified heap object, span multiple
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separately allocates pages, are not on the process stack,
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or are part of the kernel text. This kills entire classes
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of heap overflow exploits and similar kernel memory exposures.
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source security/selinux/Kconfig
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source security/smack/Kconfig
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source security/tomoyo/Kconfig
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source security/apparmor/Kconfig
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source security/loadpin/Kconfig
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source security/yama/Kconfig
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source security/integrity/Kconfig
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choice
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prompt "Default security module"
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default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
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default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
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default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
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default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
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default DEFAULT_SECURITY_DAC
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help
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Select the security module that will be used by default if the
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kernel parameter security= is not specified.
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config DEFAULT_SECURITY_SELINUX
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bool "SELinux" if SECURITY_SELINUX=y
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config DEFAULT_SECURITY_SMACK
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bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
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config DEFAULT_SECURITY_TOMOYO
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bool "TOMOYO" if SECURITY_TOMOYO=y
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config DEFAULT_SECURITY_APPARMOR
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bool "AppArmor" if SECURITY_APPARMOR=y
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config DEFAULT_SECURITY_DAC
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bool "Unix Discretionary Access Controls"
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endchoice
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config DEFAULT_SECURITY
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string
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default "selinux" if DEFAULT_SECURITY_SELINUX
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default "smack" if DEFAULT_SECURITY_SMACK
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default "tomoyo" if DEFAULT_SECURITY_TOMOYO
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default "apparmor" if DEFAULT_SECURITY_APPARMOR
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default "" if DEFAULT_SECURITY_DAC
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endmenu
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