linux

treewide: Add SPDX license identifier - Makefile/Kconfig Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2019-05-19 13:07:45 +01:00

LSM: LoadPin for kernel file loading restrictions 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>

2016-04-20 15:46:28 -07:00

LSM: LoadPin: provide enablement CONFIG Instead of being enabled by default when SECURITY_LOADPIN is selected, provide an additional (default off) config to determine the boot time behavior. As before, the "loadpin.enabled=0/1" kernel parameter remains available. Suggested-by: James Morris <jmorris@namei.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.l.morris@oracle.com>

2016-05-17 01:45:52 -07:00

LoadPin: Rename boot param "enabled" to "enforce" LoadPin's "enabled" setting is really about enforcement, not whether or not the LSM is using LSM hooks. Instead, split this out so that LSM enabling can be logically distinct from whether enforcement is happening (for example, the pinning happens when the LSM is enabled, but the pin is only checked when "enforce" is set). This allows LoadPin to continue to operate sanely in test environments once LSM enable/disable is centrally handled (i.e. we want LoadPin to be enabled separately from its enforcement). Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com>

2018-09-24 14:43:59 -07:00

LSM: LoadPin: provide enablement CONFIG Instead of being enabled by default when SECURITY_LOADPIN is selected, provide an additional (default off) config to determine the boot time behavior. As before, the "loadpin.enabled=0/1" kernel parameter remains available. Suggested-by: James Morris <jmorris@namei.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.l.morris@oracle.com>

2016-05-17 01:45:52 -07:00

loadpin: Prevent SECURITY_LOADPIN_ENFORCE=y without module decompression If modules are built compressed, and LoadPin is enforcing by default, we must have in-kernel module decompression enabled (MODULE_DECOMPRESS). Modules will fail to load without decompression built into the kernel because they'll be blocked by LoadPin. Add a depends on clause to prevent this combination. Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Douglas Anderson <dianders@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20240514224839.2526112-1-swboyd@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org>

2024-05-14 15:48:38 -07:00

LSM: LoadPin: provide enablement CONFIG Instead of being enabled by default when SECURITY_LOADPIN is selected, provide an additional (default off) config to determine the boot time behavior. As before, the "loadpin.enabled=0/1" kernel parameter remains available. Suggested-by: James Morris <jmorris@namei.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.l.morris@oracle.com>

2016-05-17 01:45:52 -07:00

LoadPin: Rename boot param "enabled" to "enforce" LoadPin's "enabled" setting is really about enforcement, not whether or not the LSM is using LSM hooks. Instead, split this out so that LSM enabling can be logically distinct from whether enforcement is happening (for example, the pinning happens when the LSM is enabled, but the pin is only checked when "enforce" is set). This allows LoadPin to continue to operate sanely in test environments once LSM enable/disable is centrally handled (i.e. we want LoadPin to be enabled separately from its enforcement). Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com>

2018-09-24 14:43:59 -07:00

LoadPin: Enable loading from trusted dm-verity devices Extend LoadPin to allow loading of kernel files from trusted dm-verity [1] devices. This change adds the concept of trusted verity devices to LoadPin. LoadPin maintains a list of root digests of verity devices it considers trusted. Userspace can populate this list through an ioctl on the new LoadPin securityfs entry 'dm-verity'. The ioctl receives a file descriptor of a file with verity digests as parameter. Verity reads the digests from this file after confirming that the file is located on the pinned root. The digest file must contain one digest per line. The list of trusted digests can only be set up once, which is typically done at boot time. When a kernel file is read LoadPin first checks (as usual) whether the file is located on the pinned root, if so the file can be loaded. Otherwise, if the verity extension is enabled, LoadPin determines whether the file is located on a verity backed device and whether the root digest of that device is in the list of trusted digests. The file can be loaded if the verity device has a trusted root digest. Background: As of now LoadPin restricts loading of kernel files to a single pinned filesystem, typically the rootfs. This works for many systems, however it can result in a bloated rootfs (and OTA updates) on platforms where multiple boards with different hardware configurations use the same rootfs image. Especially when 'optional' files are large it may be preferable to download/install them only when they are actually needed by a given board. Chrome OS uses Downloadable Content (DLC) [2] to deploy certain 'packages' at runtime. As an example a DLC package could contain firmware for a peripheral that is not present on all boards. DLCs use dm-verity to verify the integrity of the DLC content. [1] https://www.kernel.org/doc/html/latest/admin-guide/device-mapper/verity.html [2] https://chromium.googlesource.com/chromiumos/platform2/+/HEAD/dlcservice/docs/developer.md Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Acked-by: Mike Snitzer <snitzer@kernel.org> Link: https://lore.kernel.org/lkml/20220627083512.v7.2.I01c67af41d2f6525c6d023101671d7339a9bc8b5@changeid Signed-off-by: Kees Cook <keescook@chromium.org>

2022-06-27 08:35:25 -07:00

LoadPin: Require file with verity root digests to have a header LoadPin expects the file with trusted verity root digests to be an ASCII file with one digest (hex value) per line. A pinned root could contain files that meet these format requirements, even though the hex values don't represent trusted root digests. Add a new requirement to the file format which consists in the first line containing a fixed string. This prevents attackers from feeding files with an otherwise valid format to LoadPin. Suggested-by: Sarthak Kukreti <sarthakkukreti@chromium.org> Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220906181725.1.I3f51d1bb0014e5a5951be4ad3c5ad7c7ca1dfc32@changeid

2022-09-06 18:18:12 -07:00

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