Like the skcipher_walk and blkcipher_walk cases:
scatterwalk_done() is only meant to be called after a nonzero number of
bytes have been processed, since scatterwalk_pagedone() will flush the
dcache of the *previous* page. But in the error case of
ablkcipher_walk_done(), e.g. if the input wasn't an integer number of
blocks, scatterwalk_done() was actually called after advancing 0 bytes.
This caused a crash ("BUG: unable to handle kernel paging request")
during '!PageSlab(page)' on architectures like arm and arm64 that define
ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE, provided that the input was
page-aligned as in that case walk->offset == 0.
Fix it by reorganizing ablkcipher_walk_done() to skip the
scatterwalk_advance() and scatterwalk_done() if an error has occurred.
Reported-by: Liu Chao <liuchao741@huawei.com>
Fixes: bf06099db1 ("crypto: skcipher - Add ablkcipher_walk interfaces")
Cc: <stable@vger.kernel.org> # v2.6.35+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
As of GCC 9.0.0 the build is reporting warnings like:
crypto/ablkcipher.c: In function ‘crypto_ablkcipher_report’:
crypto/ablkcipher.c:374:2: warning: ‘strncpy’ specified bound 64 equals destination size [-Wstringop-truncation]
strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sizeof(rblkcipher.geniv));
~~~~~~~~~~~~~~~~~~~~~~~~~
This means the strnycpy might create a non null terminated string. Fix this by
explicitly performing '\0' termination.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Nick Desaulniers <nick.desaulniers@gmail.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Continuing from this commit: 52f5684c8e
("kernel: use macros from compiler.h instead of __attribute__((...))")
I submitted 4 total patches. They are part of task I've taken up to
increase compiler portability in the kernel. I've cleaned up the
subsystems under /kernel /mm /block and /security, this patch targets
/crypto.
There is <linux/compiler.h> which provides macros for various gcc specific
constructs. Eg: __weak for __attribute__((weak)). I've cleaned all
instances of gcc specific attributes with the right macros for the crypto
subsystem.
I had to make one additional change into compiler-gcc.h for the case when
one wants to use this: __attribute__((aligned) and not specify an alignment
factor. From the gcc docs, this will result in the largest alignment for
that data type on the target machine so I've named the macro
__aligned_largest. Please advise if another name is more appropriate.
Signed-off-by: Gideon Israel Dsouza <gidisrael@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch removes the old crypto_grab_skcipher helper and replaces
it with crypto_grab_skcipher2.
As this is the final entry point into givcipher this patch also
removes all traces of the top-level givcipher interface, including
all implicit IV generators such as chainiv.
The bottom-level givcipher interface remains until the drivers
using it are converted.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Some ciphers actually support encrypting zero length plaintexts. For
example, many AEAD modes support this. The resulting ciphertext for
those winds up being only the authentication tag, which is a result of
the key, the iv, the additional data, and the fact that the plaintext
had zero length. The blkcipher constructors won't copy the IV to the
right place, however, when using a zero length input, resulting in
some significant problems when ciphers call their initialization
routines, only to find that the ->iv parameter is uninitialized. One
such example of this would be using chacha20poly1305 with a zero length
input, which then calls chacha20, which calls the key setup routine,
which eventually OOPSes due to the uninitialized ->iv member.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Currently a number of Crypto API operations may fail when a signal
occurs. This causes nasty problems as the caller of those operations
are often not in a good position to restart the operation.
In fact there is currently no need for those operations to be
interrupted by user signals at all. All we need is for them to
be killable.
This patch replaces the relevant calls of signal_pending with
fatal_signal_pending, and wait_for_completion_interruptible with
wait_for_completion_killable, respectively.
Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Currently for skcipher IV generators they must provide givencrypt
as that is the whole point. We are currently replacing skcipher
IV generators with explicit IV generators. In order to maintain
backwards compatibility, we need to allow the IV generators to
still function as a normal skcipher when the RNG Is not present
(e.g., in the initramfs during boot). IOW everything but givencrypt
and givdecrypt will still work but those two will fail.
Therefore this patch assigns a default givencrypt that simply
returns an error should it be NULL.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Newer templates use tmpl->create and have a NULL tmpl->alloc. So
we must use tmpl->create if it is set.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When the user explicitly states that they don't care whether the
algorithm has been tested (type = CRYPTO_ALG_TESTED and mask = 0),
there is a corner case where we may erroneously return ENOENT.
This patch fixes it by correcting the logic in the test.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fixed style errors reported by checkpatch.
WARNING: Missing a blank line after declarations
+ u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
+ return max(start, end_page);
WARNING: line over 80 characters
+ scatterwalk_start(&walk->out, scatterwalk_sg_next(walk->out.sg));
WARNING: Missing a blank line after declarations
+ int err = ablkcipher_copy_iv(walk, tfm, alignmask);
+ if (err)
ERROR: do not use assignment in if condition
+ if ((err = crypto_register_instance(tmpl, inst))) {
Signed-off-by: Joshua I. James <joshua@cybercrimetech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Previously we would use eseqiv on all async ciphers in all cases,
and sync ciphers if we have more than one CPU. This meant that
chainiv is only used in the case of sync ciphers on a UP machine.
As chainiv may aid attackers by making the IV predictable, even
though this risk itself is small, the above usage pattern causes
it to further leak information about the host.
This patch addresses these issues by using eseqiv even if we're
on a UP machine.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: David S. Miller <davem@davemloft.net>
Three errors resulting in kernel memory disclosure:
1/ The structures used for the netlink based crypto algorithm report API
are located on the stack. As snprintf() does not fill the remainder of
the buffer with null bytes, those stack bytes will be disclosed to users
of the API. Switch to strncpy() to fix this.
2/ crypto_report_one() does not initialize all field of struct
crypto_user_alg. Fix this to fix the heap info leak.
3/ For the module name we should copy only as many bytes as
module_name() returns -- not as much as the destination buffer could
hold. But the current code does not and therefore copies random data
from behind the end of the module name, as the module name is always
shorter than CRYPTO_MAX_ALG_NAME.
Also switch to use strncpy() to copy the algorithm's name and
driver_name. They are strings, after all.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
These macros contain a hidden goto, and are thus extremely error
prone and make code hard to audit.
Signed-off-by: David S. Miller <davem@davemloft.net>
We lookup algorithms with crypto_alg_mod_lookup() when instantiating via
crypto_add_alg(). However, algorithms that are wrapped by an IV genearator
(e.g. aead or genicv type algorithms) need special care. The userspace
process hangs until it gets a timeout when we use crypto_alg_mod_lookup()
to lookup these algorithms. So export the lookup functions for these
algorithms and use them in crypto_add_alg().
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Stanse found a potential NULL dereference in ablkcipher_next_slow.
Even though kmalloc fails, its retval is dereferenced later. Return
from that function properly earlier.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
These are akin to the blkcipher_walk helpers.
The main differences in the async variant are:
1) Only physical walking is supported. We can't hold on to
kmap mappings across the async operation to support virtual
ablkcipher_walk operations anyways.
2) Bounce buffers used for async more need to be persistent and
freed at a later point in time when the async op completes.
Therefore we maintain a list of writeback buffers and require
that the ablkcipher_walk user call the 'complete' operation
so we can copy the bounce buffers out to the real buffers and
free up the bounce buffer chunks.
These interfaces will be used by the new Niagara2 crypto driver.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Recently we switched to using eseqiv on SMP machines in preference
over chainiv. However, eseqiv does not support stream ciphers so
they should still default to chainiv.
This patch applies the same check as done by eseqiv to weed out
the stream ciphers. In particular, all algorithms where the IV
size is not equal to the block size will now default to chainiv.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Eric Biggers
Stafford Horne
Gideon Israel Dsouza
Herbert Xu
Geliang Tang
Jason A. Donenfeld
Cristian Stoica
Joshua I. James
Mathias Krause
David S. Miller
Steffen Klassert
Davidlohr Bueso
Jiri Slaby
Richard Hartmann