If a request is backlogged, it's complete() handler will get called
twice: once with -EINPROGRESS, and once with the final error code.
af_alg's complete handler, unlike other users, does not handle the
-EINPROGRESS but instead always completes the completion that recvmsg()
is waiting on. This can lead to a return to user space while the
request is still pending in the driver. If userspace closes the sockets
before the requests are handled by the driver, this will lead to
use-after-frees (and potential crashes) in the kernel due to the tfm
having been freed.
The crashes can be easily reproduced (for example) by reducing the max
queue length in cryptod.c and running the following (from
http://www.chronox.de/libkcapi.html) on AES-NI capable hardware:
$ while true; do kcapi -x 1 -e -c '__ecb-aes-aesni' \
-k 00000000000000000000000000000000 \
-p 00000000000000000000000000000000 >/dev/null & done
Cc: stable@vger.kernel.org
Signed-off-by: Rabin Vincent <rabin.vincent@axis.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull crypto update from Herbert Xu:
- The crypto API is now documented :)
- Disallow arbitrary module loading through crypto API.
- Allow get request with empty driver name through crypto_user.
- Allow speed testing of arbitrary hash functions.
- Add caam support for ctr(aes), gcm(aes) and their derivatives.
- nx now supports concurrent hashing properly.
- Add sahara support for SHA1/256.
- Add ARM64 version of CRC32.
- Misc fixes.
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (77 commits)
crypto: tcrypt - Allow speed testing of arbitrary hash functions
crypto: af_alg - add user space interface for AEAD
crypto: qat - fix problem with coalescing enable logic
crypto: sahara - add support for SHA1/256
crypto: sahara - replace tasklets with kthread
crypto: sahara - add support for i.MX53
crypto: sahara - fix spinlock initialization
crypto: arm - replace memset by memzero_explicit
crypto: powerpc - replace memset by memzero_explicit
crypto: sha - replace memset by memzero_explicit
crypto: sparc - replace memset by memzero_explicit
crypto: algif_skcipher - initialize upon init request
crypto: algif_skcipher - removed unneeded code
crypto: algif_skcipher - Fixed blocking recvmsg
crypto: drbg - use memzero_explicit() for clearing sensitive data
crypto: drbg - use MODULE_ALIAS_CRYPTO
crypto: include crypto- module prefix in template
crypto: user - add MODULE_ALIAS
crypto: sha-mb - remove a bogus NULL check
crytpo: qat - Fix 64 bytes requests
...
Introduce helper macro for_each_cmsghdr as a wrapper of the enumerating
cmsghdr from msghdr, just cleanup.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Note that the code _using_ ->msg_iter at that point will be very
unhappy with anything other than unshifted iovec-backed iov_iter.
We still need to convert users to proper primitives.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch allows the testing of arbitrary hash functions specified
by the alg module parameter by using them in mode 300 (for sync hash)
and mode 400 (for async hash).
For example, you could do
modprobe tcrypt mode=300 alg='vmac(aes)'
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
AEAD requires the caller to specify the following information separate
from the data stream. This information allows the AEAD interface handler
to identify the AAD, ciphertext/plaintext and the authentication tag:
* Associated authentication data of arbitrary length and
length
* Length of authentication tag for encryption
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When using the algif_skcipher, the following call sequence causess a
re-initialization:
1. sendmsg with ALG_SET_OP and iov == NULL, iovlen == 0 (i.e
initializing the cipher, but not sending data)
2. sendmsg with msg->msg-controllen == 0 and iov != NULL (using the initalized
cipher handle by sending data)
In step 2, the cipher operation type (encryption or decryption) is reset
to always decryption, because the local variable of enc is put into
ctx->enc as ctx->user is still zero.
The same applies when all send data is processed and ctx->used falls to
zero followed by user space to send new data.
This patch changes the behavior to only reset the cipher operation type
(and the IV) if such configuration request is received.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
As most (all?) users of algif_skcipher are single-threaded and
therefore always write before reading from an algif_skcipher
socket, they never block and exercise that code-path.
It turns out that code path doesn't even work because we never
reload ctx->used after waking up so we never even see the new
data and immediately return an error (and a loud WARN_ON).
This patch fixes this by always reloading ctx->used.
Reported-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Stephan Mueller <smueller@chronox.de>
Compiler dead store optimization can sometimes remove final calls
to memset() used to clear sensitive data at the end of a function.
Replace trailing memset() calls with memzero_explicit() to
preclude unwanted removal.
Signed-off-by: Nickolaus Woodruff <nickolauswoodruff@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This adds the module loading prefix "crypto-" to the template lookup
as well.
For example, attempting to load 'vfat(blowfish)' via AF_ALG now correctly
includes the "crypto-" prefix at every level, correctly rejecting "vfat":
net-pf-38
algif-hash
crypto-vfat(blowfish)
crypto-vfat(blowfish)-all
crypto-vfat
Reported-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
To allow automatic loading of the crypto_user kernel module, the netlink
MODULE_ALIAS is added.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Commit e1bd95bf7c ("crypto: algif - zeroize IV buffer") and
2a6af25bef ("crypto: algif - zeroize message digest buffer")
added memzero_explicit() calls on buffers that are later on
passed back to sock_kfree_s().
This is a discussed follow-up that, instead, extends the sock
API and adds sock_kzfree_s(), which internally uses kzfree()
instead of kfree() for passing the buffers back to slab.
Having sock_kzfree_s() allows to keep the changes more minimal
by just having a drop-in replacement instead of adding
memzero_explicit() calls everywhere before sock_kfree_s().
In kzfree(), the compiler is not allowed to optimize the memset()
away and thus there's no need for memzero_explicit(). Both,
sock_kfree_s() and sock_kzfree_s() are wrappers for
__sock_kfree_s() and call into kfree() resp. kzfree(); here,
__sock_kfree_s() needs to be explicitly inlined as we want the
compiler to optimize the call and condition away and thus it
produces e.g. on x86_64 the _same_ assembler output for
sock_kfree_s() before and after, and thus also allows for
avoiding code duplication.
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Currently all get requests with an empty driver name fail with
EINVAL. Since most users actually want to supply an empty driver
name this patch removes this check.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Zeroize the buffer holding the IV used for the completed
cipher operation before the buffer is released by the
skcipher AF_ALG interface handler.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Zeroize the buffer holding the message digest calculated for the
consumer before the buffer is released by the hash AF_ALG interface
handler.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The kernel module drbg.ko is currently not loaded automatically when a
DRBG is requested by a consumer. This is due to missing MODULE_ALIAS
flags for each of the implemented DRBG types.
This patch adds aliases for each of the 22 defined DRBGs.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull /dev/random updates from Ted Ts'o:
"This adds a memzero_explicit() call which is guaranteed not to be
optimized away by GCC. This is important when we are wiping
cryptographically sensitive material"
* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
crypto: memzero_explicit - make sure to clear out sensitive data
random: add and use memzero_explicit() for clearing data
The DRBG internal buffer addition function is replaced with crypto_inc when
a buffer is to be incremented by one.
The function drbg_add_buf is moved to the CONFIG_CRYPTO_DRBG_HASH ifdef
area as it is now only needed for the Hash DRBG.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
