scatterwalk_samebuf() is never used. Remove it.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
All callers pass chain=0 to scatterwalk_crypto_chain().
Remove this unneeded parameter.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The CTR DRBG requires two SGLs pointing to input/output buffers for the
CTR AES operation. The used SGLs always have only one entry. Thus, the
SGL can be initialized during allocation time, preventing a
re-initialization of the SGLs during each call.
The performance is increased by about 1 to 3 percent depending on the
size of the requested buffer size.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
According to SP800-56A section 5.6.2.1, the public key to be processed
for the DH operation shall be checked for appropriateness. The check
shall covers the full verification test in case the domain parameter Q
is provided as defined in SP800-56A section 5.6.2.3.1. If Q is not
provided, the partial check according to SP800-56A section 5.6.2.3.2 is
performed.
The full verification test requires the presence of the domain parameter
Q. Thus, the patch adds the support to handle Q. It is permissible to
not provide the Q value as part of the domain parameters. This implies
that the interface is still backwards-compatible where so far only P and
G are to be provided. However, if Q is provided, it is imported.
Without the test, the NIST ACVP testing fails. After adding this check,
the NIST ACVP testing passes. Testing without providing the Q domain
parameter has been performed to verify the interface has not changed.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
syzbot reported a crash in vmac_final() when multiple threads
concurrently use the same "vmac(aes)" transform through AF_ALG. The bug
is pretty fundamental: the VMAC template doesn't separate per-request
state from per-tfm (per-key) state like the other hash algorithms do,
but rather stores it all in the tfm context. That's wrong.
Also, vmac_final() incorrectly zeroes most of the state including the
derived keys and cached pseudorandom pad. Therefore, only the first
VMAC invocation with a given key calculates the correct digest.
Fix these bugs by splitting the per-tfm state from the per-request state
and using the proper init/update/final sequencing for requests.
Reproducer for the crash:
#include <linux/if_alg.h>
#include <sys/socket.h>
#include <unistd.h>
int main()
{
int fd;
struct sockaddr_alg addr = {
.salg_type = "hash",
.salg_name = "vmac(aes)",
};
char buf[256] = { 0 };
fd = socket(AF_ALG, SOCK_SEQPACKET, 0);
bind(fd, (void *)&addr, sizeof(addr));
setsockopt(fd, SOL_ALG, ALG_SET_KEY, buf, 16);
fork();
fd = accept(fd, NULL, NULL);
for (;;)
write(fd, buf, 256);
}
The immediate cause of the crash is that vmac_ctx_t.partial_size exceeds
VMAC_NHBYTES, causing vmac_final() to memset() a negative length.
Reported-by: syzbot+264bca3a6e8d645550d3@syzkaller.appspotmail.com
Fixes: f1939f7c56 ("crypto: vmac - New hash algorithm for intel_txt support")
Cc: <stable@vger.kernel.org> # v2.6.32+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The poll() changes were not well thought out, and completely
unexplained. They also caused a huge performance regression, because
"->poll()" was no longer a trivial file operation that just called down
to the underlying file operations, but instead did at least two indirect
calls.
Indirect calls are sadly slow now with the Spectre mitigation, but the
performance problem could at least be largely mitigated by changing the
"->get_poll_head()" operation to just have a per-file-descriptor pointer
to the poll head instead. That gets rid of one of the new indirections.
But that doesn't fix the new complexity that is completely unwarranted
for the regular case. The (undocumented) reason for the poll() changes
was some alleged AIO poll race fixing, but we don't make the common case
slower and more complex for some uncommon special case, so this all
really needs way more explanations and most likely a fundamental
redesign.
[ This revert is a revert of about 30 different commits, not reverted
individually because that would just be unnecessarily messy - Linus ]
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds the sha384 pre-computed 0-length hash so that device
drivers can use it when an hardware engine does not support computing a
hash from a 0 length input.
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds the sha512 pre-computed 0-length hash so that device
drivers can use it when an hardware engine does not support computing a
hash from a 0 length input.
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This reverts commit eb772f37ae, as now the
x86 Salsa20 implementation has been removed and the generic helpers are
no longer needed outside of salsa20_generic.c.
We could keep this just in case someone else wants to add a new
optimized Salsa20 implementation. But given that we have ChaCha20 now
too, I think it's unlikely. And this can always be reverted back.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds a common glue code for optimized implementations of
MORUS AEAD algorithms.
Signed-off-by: Ondrej Mosnacek <omosnacek@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds the generic implementation of the MORUS family of AEAD
algorithms (MORUS-640 and MORUS-1280). The original authors of MORUS
are Hongjun Wu and Tao Huang.
At the time of writing, MORUS is one of the finalists in CAESAR, an
open competition intended to select a portfolio of alternatives to
the problematic AES-GCM:
https://competitions.cr.yp.to/caesar-submissions.htmlhttps://competitions.cr.yp.to/round3/morusv2.pdf
Signed-off-by: Ondrej Mosnacek <omosnacek@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
In preparation of adding support for the SIMD based arm64 implementation
of arm64, which requires a fallback to non-SIMD code when invoked in
certain contexts, expose the generic SM4 encrypt and decrypt routines
to other drivers.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
In preparation for the removal of VLAs[1] from crypto code.
We create 2 new compile-time constants: all ciphers implemented
in Linux have a block size less than or equal to 16 bytes and
the most demanding hw require 16 bytes alignment for the block
buffer.
We also enforce these limits in crypto_check_alg when a new
cipher is registered.
[1] http://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com
Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The lookup function in crypto_type was only used for the implicit
IV generators which have been completely removed from the crypto
API.
This patch removes the lookup function as it is now useless.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Prevent improper use of req->result field in ahash update, init, export and
import functions in drivers code. A driver should use ahash request context
if it needs to save internal state.
Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Introduce the SM4 cipher algorithms (OSCCA GB/T 32907-2016).
SM4 (GBT.32907-2016) is a cryptographic standard issued by the
Organization of State Commercial Administration of China (OSCCA)
as an authorized cryptographic algorithms for the use within China.
SMS4 was originally created for use in protecting wireless
networks, and is mandated in the Chinese National Standard for
Wireless LAN WAPI (Wired Authentication and Privacy Infrastructure)
(GB.15629.11-2003).
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
All users of ablk_helper have been converted over to crypto_simd, so
remove ablk_helper.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Now that all users of lrw_crypt() have been removed in favor of the LRW
template wrapping an ECB mode algorithm, remove lrw_crypt(). Also
remove crypto/lrw.h as that is no longer needed either; and fold
'struct lrw_table_ctx' into 'struct priv', lrw_init_table() into
setkey(), and lrw_free_table() into exit_tfm().
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Now that all users of xts_crypt() have been removed in favor of the XTS
template wrapping an ECB mode algorithm, remove xts_crypt().
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add a function to crypto_simd that registers an array of skcipher
algorithms, then allocates and registers the simd wrapper algorithms for
them. It assumes the naming scheme where the names of the underlying
algorithms are prefixed with two underscores.
Also add the corresponding 'unregister' function.
Most of the x86 crypto modules will be able to use these.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Export the Speck constants and transform context and the ->setkey(),
->encrypt(), and ->decrypt() functions so that they can be reused by the
ARM NEON implementation of Speck-XTS. The generic key expansion code
will be reused because it is not performance-critical and is not
vectorizable, while the generic encryption and decryption functions are
needed as fallbacks and for the XTS tweak encryption.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The crypto engine could actually only enqueue hash and ablkcipher request.
This patch permit it to enqueue any type of crypto_async_request.
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Tested-by: Fabien Dessenne <fabien.dessenne@st.com>
Tested-by: Fabien Dessenne <fabien.dessenne@st.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
There is no need for ahash_mcryptd_{update,final,finup,digest}(); we
should just call crypto_ahash_*() directly.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull crypto updates from Herbert Xu:
"API:
- Enforce the setting of keys for keyed aead/hash/skcipher
algorithms.
- Add multibuf speed tests in tcrypt.
Algorithms:
- Improve performance of sha3-generic.
- Add native sha512 support on arm64.
- Add v8.2 Crypto Extentions version of sha3/sm3 on arm64.
- Avoid hmac nesting by requiring underlying algorithm to be unkeyed.
- Add cryptd_max_cpu_qlen module parameter to cryptd.
Drivers:
- Add support for EIP97 engine in inside-secure.
- Add inline IPsec support to chelsio.
- Add RevB core support to crypto4xx.
- Fix AEAD ICV check in crypto4xx.
- Add stm32 crypto driver.
- Add support for BCM63xx platforms in bcm2835 and remove bcm63xx.
- Add Derived Key Protocol (DKP) support in caam.
- Add Samsung Exynos True RNG driver.
- Add support for Exynos5250+ SoCs in exynos PRNG driver"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (166 commits)
crypto: picoxcell - Fix error handling in spacc_probe()
crypto: arm64/sha512 - fix/improve new v8.2 Crypto Extensions code
crypto: arm64/sm3 - new v8.2 Crypto Extensions implementation
crypto: arm64/sha3 - new v8.2 Crypto Extensions implementation
crypto: testmgr - add new testcases for sha3
crypto: sha3-generic - export init/update/final routines
crypto: sha3-generic - simplify code
crypto: sha3-generic - rewrite KECCAK transform to help the compiler optimize
crypto: sha3-generic - fixes for alignment and big endian operation
crypto: aesni - handle zero length dst buffer
crypto: artpec6 - remove select on non-existing CRYPTO_SHA384
hwrng: bcm2835 - Remove redundant dev_err call in bcm2835_rng_probe()
crypto: stm32 - remove redundant dev_err call in stm32_cryp_probe()
crypto: axis - remove unnecessary platform_get_resource() error check
crypto: testmgr - test misuse of result in ahash
crypto: inside-secure - make function safexcel_try_push_requests static
crypto: aes-generic - fix aes-generic regression on powerpc
crypto: chelsio - Fix indentation warning
crypto: arm64/sha1-ce - get rid of literal pool
crypto: arm64/sha2-ce - move the round constant table to .rodata section
...
Pull poll annotations from Al Viro:
"This introduces a __bitwise type for POLL### bitmap, and propagates
the annotations through the tree. Most of that stuff is as simple as
'make ->poll() instances return __poll_t and do the same to local
variables used to hold the future return value'.
Some of the obvious brainos found in process are fixed (e.g. POLLIN
misspelled as POLL_IN). At that point the amount of sparse warnings is
low and most of them are for genuine bugs - e.g. ->poll() instance
deciding to return -EINVAL instead of a bitmap. I hadn't touched those
in this series - it's large enough as it is.
Another problem it has caught was eventpoll() ABI mess; select.c and
eventpoll.c assumed that corresponding POLL### and EPOLL### were
equal. That's true for some, but not all of them - EPOLL### are
arch-independent, but POLL### are not.
The last commit in this series separates userland POLL### values from
the (now arch-independent) kernel-side ones, converting between them
in the few places where they are copied to/from userland. AFAICS, this
is the least disruptive fix preserving poll(2) ABI and making epoll()
work on all architectures.
As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and
it will trigger only on what would've triggered EPOLLWRBAND on other
architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered
at all on sparc. With this patch they should work consistently on all
architectures"
* 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
make kernel-side POLL... arch-independent
eventpoll: no need to mask the result of epi_item_poll() again
eventpoll: constify struct epoll_event pointers
debugging printk in sg_poll() uses %x to print POLL... bitmap
annotate poll(2) guts
9p: untangle ->poll() mess
->si_band gets POLL... bitmap stored into a user-visible long field
ring_buffer_poll_wait() return value used as return value of ->poll()
the rest of drivers/*: annotate ->poll() instances
media: annotate ->poll() instances
fs: annotate ->poll() instances
ipc, kernel, mm: annotate ->poll() instances
net: annotate ->poll() instances
apparmor: annotate ->poll() instances
tomoyo: annotate ->poll() instances
sound: annotate ->poll() instances
acpi: annotate ->poll() instances
crypto: annotate ->poll() instances
block: annotate ->poll() instances
x86: annotate ->poll() instances
...
To allow accelerated implementations to fall back to the generic
routines, e.g., in contexts where a SIMD based implementation is
not allowed to run, expose the generic SHA3 init/update/final
routines to other modules.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
In preparation of exposing the generic SHA3 implementation to other
versions as a fallback, simplify the code, and remove an inconsistency
in the output handling (endian swabbing rsizw words of state before
writing the output does not make sense)
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
SPHINX build emits multiple warnings of kind:
warning: duplicate section name 'Note'
(when building kernel via make target 'htmldocs')
This is caused by repeated use of comments of form:
* Note: soau soaeusoa uoe
We can change the format without loss of clarity and clear the build
warnings.
Add '**[mandatory]**' or '**[optional]**' as kernel-doc field element
description prefix
This renders in HTML as (prefixes in bold)
final
[mandatory] Retrieve result from the driver. This function finalizes the
transformation and retrieves the resulting hash from the driver and
pushes it back to upper layers. No data processing happens at this
point unless hardware requires it to finish the transformation (then
the data buffered by the device driver is processed).
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Export the Salsa20 constants, transform context, and initialization
functions so that they can be reused by the x86 implementation.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Similar to what was done for the hash API, update the AEAD API to track
whether each transform has been keyed, and reject encryption/decryption
if a key is needed but one hasn't been set.
This isn't quite as important as the equivalent fix for the hash API
because AEADs always require a key, so are unlikely to be used without
one. Still, tracking the key will prevent accidental unkeyed use.
algif_aead also had to track the key anyway, so the new flag replaces
that and slightly simplifies the algif_aead implementation.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Similar to what was done for the hash API, update the skcipher API to
track whether each transform has been keyed, and reject
encryption/decryption if a key is needed but one hasn't been set.
This isn't as important as the equivalent fix for the hash API because
symmetric ciphers almost always require a key (the "null cipher" is the
only exception), so are unlikely to be used without one. Still,
tracking the key will prevent accidental unkeyed use. algif_skcipher
also had to track the key anyway, so the new flag replaces that and
simplifies the algif_skcipher implementation.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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>
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since Poly1305 requires a nonce per invocation, the Linux kernel
implementations of Poly1305 don't use the crypto API's keying mechanism
and instead expect the key and nonce as the first 32 bytes of the data.
But ->setkey() is still defined as a stub returning an error code. This
prevents Poly1305 from being used through AF_ALG and will also break it
completely once we start enforcing that all crypto API users (not just
AF_ALG) call ->setkey() if present.
Fix it by removing crypto_poly1305_setkey(), leaving ->setkey as NULL.
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Templates that use an shash spawn can use crypto_shash_alg_has_setkey()
to determine whether the underlying algorithm requires a key or not.
But there was no corresponding function for ahash spawns. Add it.
Note that the new function actually has to support both shash and ahash
algorithms, since the ahash API can be used with either.
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull crypto fixes from Herbert Xu:
"This fixes the following issues:
- racy use of ctx->rcvused in af_alg
- algif_aead crash in chacha20poly1305
- freeing bogus pointer in pcrypt
- build error on MIPS in mpi
- memory leak in inside-secure
- memory overwrite in inside-secure
- NULL pointer dereference in inside-secure
- state corruption in inside-secure
- build error without CRYPTO_GF128MUL in chelsio
- use after free in n2"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: inside-secure - do not use areq->result for partial results
crypto: inside-secure - fix request allocations in invalidation path
crypto: inside-secure - free requests even if their handling failed
crypto: inside-secure - per request invalidation
lib/mpi: Fix umul_ppmm() for MIPS64r6
crypto: pcrypt - fix freeing pcrypt instances
crypto: n2 - cure use after free
crypto: af_alg - Fix race around ctx->rcvused by making it atomic_t
crypto: chacha20poly1305 - validate the digest size
crypto: chelsio - select CRYPTO_GF128MUL
There are no init and exit callbacks, so delete its comments.
Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull crypto fixes from Herbert Xu:
"This fixes the following issues:
- fix chacha20 crash on zero-length input due to unset IV
- fix potential race conditions in mcryptd with spinlock
- only wait once at top of algif recvmsg to avoid inconsistencies
- fix potential use-after-free in algif_aead/algif_skcipher"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: af_alg - fix race accessing cipher request
crypto: mcryptd - protect the per-CPU queue with a lock
crypto: af_alg - wait for data at beginning of recvmsg
crypto: skcipher - set walk.iv for zero-length inputs
Since commit 499a66e6b6 ("crypto: null - Remove default null
blkcipher"), crypto_get_default_null_skcipher2() and
crypto_put_default_null_skcipher2() are the same as their non-2
equivalents. So switch callers of the "2" versions over to the original
versions and remove the "2" versions.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This variable was increased and decreased without any protection.
Result was an occasional misscount and negative wrap around resulting
in false resource allocation failures.
Fixes: 7d2c3f54e6 ("crypto: af_alg - remove locking in async callback")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull crypto fixes from Herbert Xu:
"This push fixes the following issues:
- buffer overread in RSA
- potential use after free in algif_aead.
- error path null pointer dereference in af_alg
- forbid combinations such as hmac(hmac(sha3)) which may crash
- crash in salsa20 due to incorrect API usage"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: salsa20 - fix blkcipher_walk API usage
crypto: hmac - require that the underlying hash algorithm is unkeyed
crypto: af_alg - fix NULL pointer dereference in
crypto: algif_aead - fix reference counting of null skcipher
crypto: rsa - fix buffer overread when stripping leading zeroes
mcryptd_enqueue_request() grabs the per-CPU queue struct and protects
access to it with disabled preemption. Then it schedules a worker on the
same CPU. The worker in mcryptd_queue_worker() guards access to the same
per-CPU variable with disabled preemption.
If we take CPU-hotplug into account then it is possible that between
queue_work_on() and the actual invocation of the worker the CPU goes
down and the worker will be scheduled on _another_ CPU. And here the
preempt_disable() protection does not work anymore. The easiest thing is
to add a spin_lock() to guard access to the list.
Another detail: mcryptd_queue_worker() is not processing more than
MCRYPTD_BATCH invocation in a row. If there are still items left, then
it will invoke queue_work() to proceed with more later. *I* would
suggest to simply drop that check because it does not use a system
workqueue and the workqueue is already marked as "CPU_INTENSIVE". And if
preemption is required then the scheduler should do it.
However if queue_work() is used then the work item is marked as CPU
unbound. That means it will try to run on the local CPU but it may run
on another CPU as well. Especially with CONFIG_DEBUG_WQ_FORCE_RR_CPU=y.
Again, the preempt_disable() won't work here but lock which was
introduced will help.
In order to keep work-item on the local CPU (and avoid RR) I changed it
to queue_work_on().
Cc: stable@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When chacha20_block() outputs the keystream block, it uses 'u32' stores
directly. However, the callers (crypto/chacha20_generic.c and
drivers/char/random.c) declare the keystream buffer as a 'u8' array,
which is not guaranteed to have the needed alignment.
Fix it by having both callers declare the keystream as a 'u32' array.
For now this is preferable to switching over to the unaligned access
macros because chacha20_block() is only being used in cases where we can
easily control the alignment (stack buffers).
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Because the HMAC template didn't check that its underlying hash
algorithm is unkeyed, trying to use "hmac(hmac(sha3-512-generic))"
through AF_ALG or through KEYCTL_DH_COMPUTE resulted in the inner HMAC
being used without having been keyed, resulting in sha3_update() being
called without sha3_init(), causing a stack buffer overflow.
This is a very old bug, but it seems to have only started causing real
problems when SHA-3 support was added (requires CONFIG_CRYPTO_SHA3)
because the innermost hash's state is ->import()ed from a zeroed buffer,
and it just so happens that other hash algorithms are fine with that,
but SHA-3 is not. However, there could be arch or hardware-dependent
hash algorithms also affected; I couldn't test everything.
Fix the bug by introducing a function crypto_shash_alg_has_setkey()
which tests whether a shash algorithm is keyed. Then update the HMAC
template to require that its underlying hash algorithm is unkeyed.
Here is a reproducer:
#include <linux/if_alg.h>
#include <sys/socket.h>
int main()
{
int algfd;
struct sockaddr_alg addr = {
.salg_type = "hash",
.salg_name = "hmac(hmac(sha3-512-generic))",
};
char key[4096] = { 0 };
algfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
bind(algfd, (const struct sockaddr *)&addr, sizeof(addr));
setsockopt(algfd, SOL_ALG, ALG_SET_KEY, key, sizeof(key));
}
Here was the KASAN report from syzbot:
BUG: KASAN: stack-out-of-bounds in memcpy include/linux/string.h:341 [inline]
BUG: KASAN: stack-out-of-bounds in sha3_update+0xdf/0x2e0 crypto/sha3_generic.c:161
Write of size 4096 at addr ffff8801cca07c40 by task syzkaller076574/3044
CPU: 1 PID: 3044 Comm: syzkaller076574 Not tainted 4.14.0-mm1+ #25
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x257 lib/dump_stack.c:53
print_address_description+0x73/0x250 mm/kasan/report.c:252
kasan_report_error mm/kasan/report.c:351 [inline]
kasan_report+0x25b/0x340 mm/kasan/report.c:409
check_memory_region_inline mm/kasan/kasan.c:260 [inline]
check_memory_region+0x137/0x190 mm/kasan/kasan.c:267
memcpy+0x37/0x50 mm/kasan/kasan.c:303
memcpy include/linux/string.h:341 [inline]
sha3_update+0xdf/0x2e0 crypto/sha3_generic.c:161
crypto_shash_update+0xcb/0x220 crypto/shash.c:109
shash_finup_unaligned+0x2a/0x60 crypto/shash.c:151
crypto_shash_finup+0xc4/0x120 crypto/shash.c:165
hmac_finup+0x182/0x330 crypto/hmac.c:152
crypto_shash_finup+0xc4/0x120 crypto/shash.c:165
shash_digest_unaligned+0x9e/0xd0 crypto/shash.c:172
crypto_shash_digest+0xc4/0x120 crypto/shash.c:186
hmac_setkey+0x36a/0x690 crypto/hmac.c:66
crypto_shash_setkey+0xad/0x190 crypto/shash.c:64
shash_async_setkey+0x47/0x60 crypto/shash.c:207
crypto_ahash_setkey+0xaf/0x180 crypto/ahash.c:200
hash_setkey+0x40/0x90 crypto/algif_hash.c:446
alg_setkey crypto/af_alg.c:221 [inline]
alg_setsockopt+0x2a1/0x350 crypto/af_alg.c:254
SYSC_setsockopt net/socket.c:1851 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1830
entry_SYSCALL_64_fastpath+0x1f/0x96
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
