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Eric Biggers 2f00eb2790 crypto: hash - prevent using keyed hashes without setting key
commit 9fa68f6200 upstream.

Currently, almost none of the keyed hash algorithms check whether a key
has been set before proceeding.  Some algorithms are okay with this and
will effectively just use a key of all 0's or some other bogus default.
However, others will severely break, as demonstrated using
"hmac(sha3-512-generic)", the unkeyed use of which causes a kernel crash
via a (potentially exploitable) stack buffer overflow.

A while ago, this problem was solved for AF_ALG by pairing each hash
transform with a 'has_key' bool.  However, there are still other places
in the kernel where userspace can specify an arbitrary hash algorithm by
name, and the kernel uses it as unkeyed hash without checking whether it
is really unkeyed.  Examples of this include:

    - KEYCTL_DH_COMPUTE, via the KDF extension
    - dm-verity
    - dm-crypt, via the ESSIV support
    - dm-integrity, via the "internal hash" mode with no key given
    - drbd (Distributed Replicated Block Device)

This bug is especially bad for KEYCTL_DH_COMPUTE as that requires no
privileges to call.

Fix the bug for all users by adding a flag CRYPTO_TFM_NEED_KEY to the
->crt_flags of each hash transform that indicates whether the transform
still needs to be keyed or not.  Then, make the hash init, import, and
digest functions return -ENOKEY if the key is still needed.

The new flag also replaces the 'has_key' bool which algif_hash was
previously using, thereby simplifying the algif_hash implementation.

Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2018-02-16 20:23:00 +01:00
arch crypto: hash - annotate algorithms taking optional key 2018-02-16 20:23:00 +01:00
block block: don't let passthrough IO go into .make_request_fn() 2018-01-02 20:31:05 +01:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto crypto: hash - prevent using keyed hashes without setting key 2018-02-16 20:23:00 +01:00
Documentation arm64: cpu_errata: Add Kryo to Falkor 1003 errata 2018-02-16 20:22:48 +01:00
drivers crypto: hash - annotate algorithms taking optional key 2018-02-16 20:23:00 +01:00
firmware License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs kernfs: fix regression in kernfs_fop_write caused by wrong type 2018-02-16 20:22:59 +01:00
include crypto: hash - prevent using keyed hashes without setting key 2018-02-16 20:23:00 +01:00
init bpf: introduce BPF_JIT_ALWAYS_ON config 2018-01-31 14:03:49 +01:00
ipc License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kernel sched/rt: Up the root domain ref count when passing it around via IPIs 2018-02-16 20:22:44 +01:00
lib test_firmware: fix missing unlock on error in config_num_requests_store() 2018-02-03 17:39:24 +01:00
mm Revert "defer call to mem_cgroup_sk_alloc()" 2018-02-13 10:19:48 +01:00
net dccp: CVE-2017-8824: use-after-free in DCCP code 2018-02-16 20:22:45 +01:00
samples samples/bpf: adjust rlimit RLIMIT_MEMLOCK for xdp1 2017-12-20 10:10:31 +01:00
scripts kbuild: rpm-pkg: keep spec file until make mrproper 2018-02-13 10:19:46 +01:00
security ima/policy: fix parsing of fsuuid 2018-02-03 17:38:53 +01:00
sound ASoC: pcm512x: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE 2018-02-07 11:12:20 -08:00
tools objtool: Warn on stripped section symbol 2018-02-07 11:12:21 -08:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support 2018-02-16 20:22:55 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: rpm-pkg: keep spec file until make mrproper 2018-02-13 10:19:46 +01:00
.mailmap .mailmap: Add Maciej W. Rozycki's Imagination e-mail address 2017-11-10 12:16:15 -08:00
COPYING [PATCH] update FSF address in COPYING 2005-09-10 10:06:29 -07:00
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Merge branch 'akpm' (patches from Andrew) 2017-11-09 18:26:51 -08:00
Makefile Linux 4.14.19 2018-02-13 10:19:50 +01:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

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.