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authorEduard Zingerman <eddyz87@gmail.com>2026-09-04 01:33:23 -0700
committerKumar Kartikeya Dwivedi <memxor@gmail.com>2026-09-04 12:58:04 +0200
commit836b2fe544a5e9b5ce116622cb36fba33838c6fd (patch)
tree95e38e4aaa0a6a78e373148b3d0af4aa2ab3d371 /Documentation/admin-guide/sysctl/crypto.rst
downloadlinux-stable-836b2fe544a5e9b5ce116622cb36fba33838c6fd.tar.gz
linux-stable-836b2fe544a5e9b5ce116622cb36fba33838c6fd.zip
selftests/bpf: Check that JMP32 pointer vs zero jumps are not predictedgrafted
Add jmp32_ptr_vs_zero_jne: the fall-through of the 32-bit compare, which the verifier used to skip, contains an out of bounds map value access, hence w/o the previous patch the program is accepted. See previous patch for detailed description. Reported-by: Nicholas Carlini <npc@anthropic.com> Suggested-by: Nicholas Carlini <npc@anthropic.com> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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+=================
+/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_)