kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-10 20:48:12 +00:00
Code Issues Releases Packages Activity
No description
1,323,875 commits 117 branches 5,827 tags 6.3 GiB
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Eric Biggers 2890601f54 crypto: vmac - remove unused VMAC algorithm 
Remove the vmac64 template, as it has no known users.  It also continues
to have longstanding bugs such as alignment violations (see
https://lore.kernel.org/r/20241226134847.6690-1-evepolonium@gmail.com/).

This code was added in 2009 by commit f1939f7c56 ("crypto: vmac - New
hash algorithm for intel_txt support").  Based on the mention of
intel_txt support in the commit title, it seems it was added as a
prerequisite for the contemporaneous patch
"intel_txt: add s3 userspace memory integrity verification"
(https://lore.kernel.org/r/4ABF2B50.6070106@intel.com/).  In the design
proposed by that patch, when an Intel Trusted Execution Technology (TXT)
enabled system resumed from suspend, the "tboot" trusted executable
launched the Linux kernel without verifying userspace memory, and then
the Linux kernel used VMAC to verify userspace memory.

However, that patch was never merged, as reviewers had objected to the
design.  It was later reworked into commit 4bd96a7a81 ("x86, tboot:
Add support for S3 memory integrity protection") which made tboot verify
the memory instead.  Thus the VMAC support in Linux was never used.

No in-tree user has appeared since then, other than potentially the
usual components that allow specifying arbitrary hash algorithms by
name, namely AF_ALG and dm-integrity.  However there are no indications
that VMAC is being used with these components.  Debian Code Search and
web searches for "vmac64" (the actual algorithm name) do not return any
results other than the kernel itself, suggesting that it does not appear
in any other code or documentation.  Explicitly grepping the source code
of the usual suspects (libell, iwd, cryptsetup) finds no matches either.

Before 2018, the vmac code was also completely broken due to using a
hardcoded nonce and the wrong endianness for the MAC.  It was then fixed
by commit ed331adab3 ("crypto: vmac - add nonced version with big
endian digest") and commit 0917b87312 ("crypto: vmac - remove insecure
version with hardcoded nonce").  These were intentionally breaking
changes that changed all the computed MAC values as well as the
algorithm name ("vmac" to "vmac64").  No complaints were ever received
about these breaking changes, strongly suggesting the absence of users.

The reason I had put some effort into fixing this code in 2018 is
because it was used by an out-of-tree driver.  But if it is still needed
in that particular out-of-tree driver, the code can be carried in that
driver instead.  There is no need to carry it upstream.

Cc: Atharva Tiwari <evepolonium@gmail.com>
Cc: Shane Wang <shane.wang@intel.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
History 2025-01-04 08:52:03 +08:00
arch crypto: vmac - remove unused VMAC algorithm 2025-01-04 08:52:03 +08:00
block blk-mq: move cpuhp callback registering out of q->sysfs_lock 2024-12-06 09:48:46 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: vmac - remove unused VMAC algorithm 2025-01-04 08:52:03 +08:00
Documentation dt-bindings: crypto: qcom,prng: document ipq9574, ipq5424 and ipq5322 2025-01-04 08:52:03 +08:00
drivers crypto: iaa - Fix IAA disabling that occurs when sync_mode is set to 'async' 2024-12-28 19:49:23 +08:00
fs 24 hotfixes. 17 are cc:stable. 15 are MM and 9 are non-MM. 2024-12-08 11:26:13 -08:00
include crypto: lib/gf128mul - Remove some bbe deadcode 2024-12-21 22:46:24 +08:00
init - The series "resource: A couple of cleanups" from Andy Shevchenko 2024-11-25 16:09:48 -08:00
io_uring io_uring: Change res2 parameter type in io_uring_cmd_done 2024-12-03 06:33:13 -07:00
ipc - The series "resource: A couple of cleanups" from Andy Shevchenko 2024-11-25 16:09:48 -08:00
kernel - Fix a /proc/interrupts formatting regression 2024-12-08 11:54:04 -08:00
lib crypto: lib/aesgcm - Reduce stack usage in libaesgcm_init 2024-12-28 19:49:22 +08:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm 24 hotfixes. 17 are cc:stable. 15 are MM and 9 are non-MM. 2024-12-08 11:26:13 -08:00
net BPF fixes: 2024-12-06 15:07:48 -08:00
rust block-6.13-20242901 2024-11-30 15:47:29 -08:00
samples BPF fixes: 2024-12-06 15:07:48 -08:00
scripts Kbuild fixes for v6.13 2024-12-08 12:01:06 -08:00
security Including fixes from can and netfilter. 2024-12-05 10:25:06 -08:00
sound sound fixes for 6.13-rc2 2024-12-06 11:46:39 -08:00
tools 24 hotfixes. 17 are cc:stable. 15 are MM and 9 are non-MM. 2024-12-08 11:26:13 -08:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt VFIO updates for v6.13 2024-11-27 12:57:03 -08:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: enable Clippy's check-private-items 2024-10-07 21:39:57 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.13 2024-11-30 13:41:50 -08:00
.mailmap media updates for v6.13-rc1 2024-11-20 14:01:15 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS cgroup: Changes for v6.13 2024-11-20 09:54:49 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: Move rhashtable over to linux-crypto 2024-12-10 13:44:21 +08:00
Makefile Linux 6.13-rc2 2024-12-08 14:03:39 -08:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

README 

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.