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path: root/drivers/base/firmware_loader/fallback_platform.c
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2020-10-05firmware: Store opt_flags in fw_privKees Cook
Instead of passing opt_flags around so much, store it in the private structure so it can be examined by internals without needing to add more arguments to functions. Co-developed-by: Scott Branden <scott.branden@broadcom.com> Signed-off-by: Scott Branden <scott.branden@broadcom.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201002173828.2099543-15-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-05firmware_loader: Use security_post_load_data()Kees Cook
Now that security_post_load_data() is wired up, use it instead of the NULL file argument style of security_post_read_file(), and update the security_kernel_load_data() call to indicate that a security_kernel_post_load_data() call is expected. Wire up the IMA check to match earlier logic. Perhaps a generalized change to ima_post_load_data() might look something like this: return process_buffer_measurement(buf, size, kernel_load_data_id_str(load_id), read_idmap[load_id] ?: FILE_CHECK, 0, NULL); Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Link: https://lore.kernel.org/r/20201002173828.2099543-10-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-05LSM: Introduce kernel_post_load_data() hookKees Cook
There are a few places in the kernel where LSMs would like to have visibility into the contents of a kernel buffer that has been loaded or read. While security_kernel_post_read_file() (which includes the buffer) exists as a pairing for security_kernel_read_file(), no such hook exists to pair with security_kernel_load_data(). Earlier proposals for just using security_kernel_post_read_file() with a NULL file argument were rejected (i.e. "file" should always be valid for the security_..._file hooks, but it appears at least one case was left in the kernel during earlier refactoring. (This will be fixed in a subsequent patch.) Since not all cases of security_kernel_load_data() can have a single contiguous buffer made available to the LSM hook (e.g. kexec image segments are separately loaded), there needs to be a way for the LSM to reason about its expectations of the hook coverage. In order to handle this, add a "contents" argument to the "kernel_load_data" hook that indicates if the newly added "kernel_post_load_data" hook will be called with the full contents once loaded. That way, LSMs requiring full contents can choose to unilaterally reject "kernel_load_data" with contents=false (which is effectively the existing hook coverage), but when contents=true they can allow it and later evaluate the "kernel_post_load_data" hook once the buffer is loaded. With this change, LSMs can gain coverage over non-file-backed data loads (e.g. init_module(2) and firmware userspace helper), which will happen in subsequent patches. Additionally prepare IMA to start processing these cases. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: KP Singh <kpsingh@google.com> Link: https://lore.kernel.org/r/20201002173828.2099543-9-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-05fs/kernel_read_file: Remove FIRMWARE_EFI_EMBEDDED enumKees Cook
The "FIRMWARE_EFI_EMBEDDED" enum is a "where", not a "what". It should not be distinguished separately from just "FIRMWARE", as this confuses the LSMs about what is being loaded. Additionally, there was no actual validation of the firmware contents happening. Fixes: e4c2c0ff00ec ("firmware: Add new platform fallback mechanism and firmware_request_platform()") Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Scott Branden <scott.branden@broadcom.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201002173828.2099543-3-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-25firmware_loader: EFI firmware loader must handle pre-allocated bufferKees Cook
The EFI platform firmware fallback would clobber any pre-allocated buffers. Instead, correctly refuse to reallocate when too small (as already done in the sysfs fallback), or perform allocation normally when needed. Fixes: e4c2c0ff00ec ("firmware: Add new platform fallback mechanism and firmware_request_platform()") Cc: stable@vger.kernel.org Acked-by: Scott Branden <scott.branden@broadcom.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20200724213640.389191-4-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27firmware_loader: change enum fw_opt to u32Scott Branden
"enum fw_opt" is not used as an enum. Change fw_opt to u32 as FW_OPT_* values are OR'd together. Signed-off-by: Scott Branden <scott.branden@broadcom.com> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20200522231202.13681-1-scott.branden@broadcom.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-20firmware: Add new platform fallback mechanism and firmware_request_platform()Hans de Goede
In some cases the platform's main firmware (e.g. the UEFI fw) may contain an embedded copy of device firmware which needs to be (re)loaded into the peripheral. Normally such firmware would be part of linux-firmware, but in some cases this is not feasible, for 2 reasons: 1) The firmware is customized for a specific use-case of the chipset / use with a specific hardware model, so we cannot have a single firmware file for the chipset. E.g. touchscreen controller firmwares are compiled specifically for the hardware model they are used with, as they are calibrated for a specific model digitizer. 2) Despite repeated attempts we have failed to get permission to redistribute the firmware. This is especially a problem with customized firmwares, these get created by the chip vendor for a specific ODM and the copyright may partially belong with the ODM, so the chip vendor cannot give a blanket permission to distribute these. This commit adds a new platform fallback mechanism to the firmware loader which will try to lookup a device fw copy embedded in the platform's main firmware if direct filesystem lookup fails. Drivers which need such embedded fw copies can enable this fallback mechanism by using the new firmware_request_platform() function. Note that for now this is only supported on EFI platforms and even on these platforms firmware_fallback_platform() only works if CONFIG_EFI_EMBEDDED_FIRMWARE is enabled (this gets selected by drivers which need this), in all other cases firmware_fallback_platform() simply always returns -ENOENT. Reported-by: Dave Olsthoorn <dave@bewaar.me> Suggested-by: Peter Jones <pjones@redhat.com> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20200115163554.101315-5-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>