diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-20 08:15:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-20 08:15:23 -0700 |
| commit | bdab18633a302c82b5e5d5dbc4e38b0baf9c0837 (patch) | |
| tree | 0446500af9a76d4e8b2a72a0a41391ceede73a10 /Documentation/admin-guide/sysctl/crypto.rst | |
| download | linux-stable-bdab18633a302c82b5e5d5dbc4e38b0baf9c0837.tar.gz linux-stable-bdab18633a302c82b5e5d5dbc4e38b0baf9c0837.zip | |
Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipgrafted
Pull futex fix from Ingo Molnar:
- Also allocate a default private futex hash on vfork() as well, to
avoid races with (private) futex waiters (Peter Zijlstra)
* tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Also allocate private hash on vfork()
Diffstat (limited to 'Documentation/admin-guide/sysctl/crypto.rst')
| -rw-r--r-- | Documentation/admin-guide/sysctl/crypto.rst | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/Documentation/admin-guide/sysctl/crypto.rst b/Documentation/admin-guide/sysctl/crypto.rst new file mode 100644 index 000000000..9a1bd5328 --- /dev/null +++ b/Documentation/admin-guide/sysctl/crypto.rst @@ -0,0 +1,83 @@ +================= +/proc/sys/crypto/ +================= + +These files show up in ``/proc/sys/crypto/``, depending on the +kernel configuration: + +.. contents:: :local: + +.. _af_alg_restrict: + +af_alg_restrict +=============== + +Controls the level of restriction of AF_ALG. + +AF_ALG is a deprecated and rarely-used userspace interface that is a +frequent source of vulnerabilities. It also unnecessarily exposes a +large number of kernel implementation details. For more information +about AF_ALG, see :ref:`Documentation/crypto/userspace-if.rst +<crypto_userspace_interface>`. + +Starting in Linux v7.3, AF_ALG supports only a limited set of +algorithms by default. This sysctl allows the system administrator to +remove this restriction when needed for compatibility reasons, or to +go further and disable AF_ALG entirely. The default value is 1. + +=== ================================================================== +0 AF_ALG is unrestricted. + +1 AF_ALG is supported with a limited list of algorithms. The list + is designed for compatibility with known users such as iwd and + bluez that haven't yet been fixed to use userspace crypto code. + + Specifically, there is an allowlist for unprivileged processes + and a somewhat longer allowlist for processes that hold + CAP_SYS_ADMIN or CAP_NET_ADMIN in the initial user namespace. + + Attempts to bind() an AF_ALG socket with a disallowed algorithm + fail with ENOENT. + +2 AF_ALG is completely disabled. Attempts to create an AF_ALG + socket fail with EAFNOSUPPORT. +=== ================================================================== + +fips_enabled +============ + +Read-only flag that indicates whether FIPS mode is enabled. + +- ``0``: FIPS mode is disabled (default). +- ``1``: FIPS mode is enabled. + +This value is set at boot time via the ``fips=1`` kernel command line +parameter. When enabled, the cryptographic API will restrict the use +of certain algorithms and perform self-tests to ensure compliance with +FIPS (Federal Information Processing Standards) requirements, such as +FIPS 140-2 and the newer FIPS 140-3, depending on the kernel +configuration and the module in use. + +fips_name +========= + +Read-only file that contains the name of the FIPS module currently in use. +The value is typically configured via the ``CONFIG_CRYPTO_FIPS_NAME`` +kernel configuration option. + +fips_version +============ + +Read-only file that contains the version string of the FIPS module. +If ``CONFIG_CRYPTO_FIPS_CUSTOM_VERSION`` is set, it uses the value from +``CONFIG_CRYPTO_FIPS_VERSION``. Otherwise, it defaults to the kernel +release version (``UTS_RELEASE``). + +Copyright (c) 2026, Shubham Chakraborty <chakrabortyshubham66@gmail.com> + +For general info and legal blurb, please look in +Documentation/admin-guide/sysctl/index.rst. + +.. See scripts/check-sysctl-docs to keep this up to date: +.. scripts/check-sysctl-docs -vtable="crypto" \ +.. $(git grep -l register_sysctl_) |
