c1a964bb90
[ Upstream commit 47add87ad181473e5ef2438918669540ba5016a6 ] Unsupported filesystems currently do not enforce any signatures. Add support for signature enforcement of the "original" and "portable & immutable" signatures when EVM_INIT_X509 is enabled. The "original" signature type contains filesystem specific metadata. Thus it cannot be copied up and verified. However with EVM_INIT_X509 and EVM_ALLOW_METADATA_WRITES enabled, the "original" file signature may be written. When EVM_ALLOW_METADATA_WRITES is not set or once it is removed from /sys/kernel/security/evm by setting EVM_INIT_HMAC for example, it is not possible to write or remove xattrs on the overlay filesystem. This change still prevents EVM from writing HMAC signatures on unsupported filesystem when EVM_INIT_HMAC is enabled. Co-developed-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.