tfm is assigned first, so it does not need to initialize
the assignment.
Signed-off-by: Li zeming <zeming@nfschina.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Use it straight away in crypto_clone_cipher(), as that is not meant to
sleep.
Fixes: 51d8d6d0f4 ("crypto: cipher - Add crypto_clone_cipher")
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Purge crypto_type::init() as well.
The last user seems to be gone with commit d63007eb95 ("crypto:
ablkcipher - remove deprecated and unused ablkcipher support").
Signed-off-by: Dmitry Safonov <dima@arista.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds the helper crypto_clone_tfm. The purpose is to
allocate a tfm object with GFP_ATOMIC. As we cannot sleep, the
object has to be cloned from an existing tfm object.
This allows code paths that cannot otherwise allocate a crypto_tfm
object to do so. Once a new tfm has been obtained its key could
then be changed without impacting other users.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add a crypto_tfm_get interface to allow tfm objects to be shared.
They can still be freed in the usual way.
This should only be done with tfm objects with no keys. You must
also not modify the tfm flags in any way once it becomes shared.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch does the final flag day conversion of all completion
functions which are now all contained in the Crypto API.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The crypto_boot_test_finished static key is unnecessary when self-tests
are disabled in the kconfig, so optimize it out accordingly, along with
the entirety of crypto_start_tests(). This mainly avoids the overhead
of an unnecessary static_branch_enable() on every boot.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Currently, registering an algorithm with the crypto API always causes a
notification to be posted to the "cryptomgr", which then creates a
kthread to self-test the algorithm. However, if self-tests are disabled
in the kconfig (as is the default option), then this kthread just
notifies waiters that the algorithm has been tested, then exits.
This causes a significant amount of overhead, especially in the kthread
creation and destruction, which is not necessary at all. For example,
in a quick test I found that booting a "minimum" x86_64 kernel with all
the crypto options enabled (except for the self-tests) takes about 400ms
until PID 1 can start. Of that, a full 13ms is spent just doing this
pointless dance, involving a kthread being created, run, and destroyed
over 200 times. That's over 3% of the entire kernel start time.
Fix this by just skipping the creation of the test larval and the
posting of the registration notification entirely, when self-tests are
disabled.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.
Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The double `to' is duplicated in the comment, remove one.
Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Currently we do not distinguish between algorithms that fail on
the self-test vs. those which are disabled in FIPS mode (not allowed).
Both are marked as having failed the self-test.
Recently the need arose to allow the usage of certain algorithms only
as arguments to specific template instantiations in FIPS mode. For
example, standalone "dh" must be blocked, but e.g. "ffdhe2048(dh)" is
allowed. Other potential use cases include "cbcmac(aes)", which must
only be used with ccm(), or "ghash", which must be used only for
gcm().
This patch allows this scenario by adding a new flag FIPS_INTERNAL to
indicate those algorithms that are not FIPS-allowed. They can then be
used as template arguments only, i.e. when looked up via
crypto_grab_spawn() to be more specific. The FIPS_INTERNAL bit gets
propagated upwards recursively into the surrounding template
instances, until the construction eventually matches an explicit
testmgr entry with ->fips_allowed being set, if any.
The behaviour to skip !->fips_allowed self-test executions in FIPS
mode will be retained. Note that this effectively means that
FIPS_INTERNAL algorithms are handled very similarly to the INTERNAL
ones in this regard. It is expected that the FIPS_INTERNAL algorithms
will receive sufficient testing when the larger constructions they're
a part of, if any, get exercised by testmgr.
Note that as a side-effect of this patch algorithms which are not
FIPS-allowed will now return ENOENT instead of ELIBBAD. Hopefully
this is not an issue as some people were relying on this already.
Link: https://lore.kernel.org/r/YeEVSaMEVJb3cQkq@gondor.apana.org.au
Originally-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The soft dependency on cryptomgr is only needed in algapi because
if algapi isn't present then no algorithms can be loaded. This
also fixes the case where api is built-in but algapi is built as
a module as the soft dependency would otherwise get lost.
Fixes: 8ab23d547f ("crypto: api - Add softdep on cryptomgr")
Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The delayed boot-time testing patch created a dependency loop
between api.c and algapi.c because it added a crypto_alg_tested
call to the former when the crypto manager is disabled.
We could instead avoid creating the test larvals if the crypto
manager is disabled. This avoids the dependency loop as well
as saving some unnecessary work, albeit in a very unlikely case.
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: kernel test robot <lkp@intel.com>
Fixes: adad556efc ("crypto: api - Fix built-in testing dependency failures")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
We need to export crypto_boot_test_finished in case api.c is
built-in while algapi.c is built as a module.
Fixes: adad556efc ("crypto: api - Fix built-in testing dependency failures")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Stephen Rothwell <sfr@canb.auug.org.au> # ppc32 build
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When complex algorithms that depend on other algorithms are built
into the kernel, the order of registration must be done such that
the underlying algorithms are ready before the ones on top are
registered. As otherwise they would fail during the self-test
which is required during registration.
In the past we have used subsystem initialisation ordering to
guarantee this. The number of such precedence levels are limited
and they may cause ripple effects in other subsystems.
This patch solves this problem by delaying all self-tests during
boot-up for built-in algorithms. They will be tested either when
something else in the kernel requests for them, or when we have
finished registering all built-in algorithms, whichever comes
earlier.
Reported-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Given that crypto_alloc_tfm() may return ERR pointers, and to avoid
crashes on obscure error paths where such pointers are presented to
crypto_destroy_tfm() (such as [0]), add an ERR_PTR check there
before dereferencing the second argument as a struct crypto_tfm
pointer.
[0] https://lore.kernel.org/linux-crypto/000000000000de949705bc59e0f6@google.com/
Reported-by: syzbot+12cf5fbfdeba210a89dd@syzkaller.appspotmail.com
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
As said by Linus:
A symmetric naming is only helpful if it implies symmetries in use.
Otherwise it's actively misleading.
In "kzalloc()", the z is meaningful and an important part of what the
caller wants.
In "kzfree()", the z is actively detrimental, because maybe in the
future we really _might_ want to use that "memfill(0xdeadbeef)" or
something. The "zero" part of the interface isn't even _relevant_.
The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.
Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.
The renaming is done by using the command sequence:
git grep -w --name-only kzfree |\
xargs sed -i 's/kzfree/kfree_sensitive/'
followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.
[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For a Linux server with NUMA, there are possibly multiple (de)compressors
which are either local or remote to some NUMA node. Some drivers will
automatically use the (de)compressor near the CPU calling acomp_alloc().
However, it is not necessarily correct because users who send acomp_req
could be from different NUMA node with the CPU which allocates acomp.
Just like kernel has kmalloc() and kmalloc_node(), here crypto can have
same support.
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
There are two problems in crypto_spawn_alg. First of all it may
return spawn->alg even if spawn->dead is set. This results in a
double-free as detected by syzbot.
Secondly the setting of the DYING flag is racy because we hold
the read-lock instead of the write-lock. We should instead call
crypto_shoot_alg in a safe manner by gaining a refcount, dropping
the lock, and then releasing the refcount.
This patch fixes both problems.
Reported-by: syzbot+fc0674cde00b66844470@syzkaller.appspotmail.com
Fixes: 4f87ee118d ("crypto: api - Do not zap spawn->alg")
Fixes: 73669cc556 ("crypto: api - Fix race condition in...")
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When CONFIG_CRYPTO_MANAGER_EXTRA_TESTS=y, the first lookup of an
algorithm that needs to be instantiated using a template will always get
the generic implementation, even when an accelerated one is available.
This happens because the extra self-tests for the accelerated
implementation allocate the generic implementation for comparison
purposes, and then crypto_alg_tested() for the generic implementation
"fulfills" the original request (i.e. sets crypto_larval::adult).
This patch fixes this by only fulfilling the original request if
we are currently the best outstanding larval as judged by the
priority. If we're not the best then we will ask all waiters on
that larval request to retry the lookup.
Note that this patch introduces a behaviour change when the module
providing the new algorithm is unregistered during the process.
Previously we would have failed with ENOENT, after the patch we
will instead redo the lookup.
Fixes: 9a8a6b3f09 ("crypto: testmgr - fuzz hashes against...")
Fixes: d435e10e67 ("crypto: testmgr - fuzz skciphers against...")
Fixes: 40153b10d9 ("crypto: testmgr - fuzz AEADs against...")
Reported-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The function crypto_spawn_alg is racy because it drops the lock
before shooting the dying algorithm. The algorithm could disappear
altogether before we shoot it.
This patch fixes it by moving the shooting into the locked section.
Fixes: 6bfd48096f ("[CRYPTO] api: Added spawns")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Of the three fields in crt_u.cipher (struct cipher_tfm), ->cit_setkey()
is pointless because it always points to setkey() in crypto/cipher.c.
->cit_decrypt_one() and ->cit_encrypt_one() are slightly less pointless,
since if the algorithm doesn't have an alignmask, they are set directly
to ->cia_encrypt() and ->cia_decrypt(). However, this "optimization"
isn't worthwhile because:
- The "cipher" algorithm type is the only algorithm still using crt_u,
so it's bloating every struct crypto_tfm for every algorithm type.
- If the algorithm has an alignmask, this "optimization" actually makes
things slower, as it causes 2 indirect calls per block rather than 1.
- It adds extra code complexity.
- Some templates already call ->cia_encrypt()/->cia_decrypt() directly
instead of going through ->cit_encrypt_one()/->cit_decrypt_one().
- The "cipher" algorithm type never gives optimal performance anyway.
For that, a higher-level type such as skcipher needs to be used.
Therefore, just remove the extra indirection, and make
crypto_cipher_setkey(), crypto_cipher_encrypt_one(), and
crypto_cipher_decrypt_one() be direct calls into crypto/cipher.c.
Also remove the unused function crypto_cipher_cast().
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crt_u.compress (struct compress_tfm) is pointless because its two
fields, ->cot_compress() and ->cot_decompress(), always point to
crypto_compress() and crypto_decompress().
Remove this pointless indirection, and just make crypto_comp_compress()
and crypto_comp_decompress() be direct calls to what used to be
crypto_compress() and crypto_decompress().
Also remove the unused function crypto_comp_cast().
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Update a comment to refer to crypto_alloc_skcipher() rather than
crypto_alloc_blkcipher() (the latter having been removed).
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The crypto API requires cryptomgr to be present for probing to work
so we need a softdep to ensure that cryptomgr is added to the
initramfs.
This was usually not a problem because until very recently it was
not practical to build crypto API as module but with the recent
work to eliminate direct AES users this is now possible.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Now that all "blkcipher" algorithms have been converted to "skcipher",
remove the blkcipher algorithm type.
The skcipher (symmetric key cipher) algorithm type was introduced a few
years ago to replace both blkcipher and ablkcipher (synchronous and
asynchronous block cipher). The advantages of skcipher include:
- A much less confusing name, since none of these algorithm types have
ever actually been for raw block ciphers, but rather for all
length-preserving encryption modes including block cipher modes of
operation, stream ciphers, and other length-preserving modes.
- It unified blkcipher and ablkcipher into a single algorithm type
which supports both synchronous and asynchronous implementations.
Note, blkcipher already operated only on scatterlists, so the fact
that skcipher does too isn't a regression in functionality.
- Better type safety by using struct skcipher_alg, struct
crypto_skcipher, etc. instead of crypto_alg, crypto_tfm, etc.
- It sometimes simplifies the implementations of algorithms.
Also, the blkcipher API was no longer being tested.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When EVM attempts to appraise a file signed with a crypto algorithm the
kernel doesn't have support for, it will cause the kernel to trigger a
module load. If the EVM policy includes appraisal of kernel modules this
will in turn call back into EVM - since EVM is holding a lock until the
crypto initialisation is complete, this triggers a deadlock. Add a
CRYPTO_NOLOAD flag and skip module loading if it's set, and add that flag
in the EVM case in order to fail gracefully with an error message
instead of deadlocking.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Commit eb02c38f01 ("crypto: api - Keep failed instances alive") is
making allocating crypto transforms sometimes fail with ELIBBAD, when
multiple processes try to access encrypted files with fscrypt for the
first time since boot. The problem is that the "request larval" for the
algorithm is being mistaken for an algorithm which failed its tests.
Fix it by only returning ELIBBAD for "non-larval" algorithms. Also
don't leak a reference to the algorithm.
Fixes: eb02c38f01 ("crypto: api - Keep failed instances alive")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch reverts commit 9c521a200b ("crypto: api - remove
instance when test failed") and fixes the underlying problem
in a different way.
To recap, prior to the reverted commit, an instance that fails
a self-test is kept around. However, it would satisfy any new
lookups against its name and therefore the system may accumlulate
an unbounded number of failed instances for the same algorithm
name.
The reverted commit fixed it by unregistering the instance. Hoever,
this still does not prevent the creation of the same failed instance
over and over again each time the name is looked up.
This patch fixes it by keeping the failed instance around, just as
we would if it were a normal algorithm. However, the lookup code
has been udpated so that we do not attempt to create another
instance as long as this failed one is still registered. Of course,
you could still force a new creation by deleting the instance from
user-space.
A new error (ELIBBAD) has been commandeered for this purpose and
will be returned when all registered algorithm of a given name
have failed the self-test.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The function crypto_alg_lookup is only usd within the crypto API
and should be not be exported to the modules. This patch marks
it as a static function.
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>
Reference counters should use refcount_t rather than atomic_t, since the
refcount_t implementation can prevent overflows, reducing the
exploitability of reference leak bugs. crypto_alg.cra_refcount is a
reference counter with the usual semantics, so switch it over to
refcount_t.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto_larval_lookup() is not used outside of crypto/api.c, so unexport
it and mark it 'static'.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Invoking a possibly async. crypto op and waiting for completion
while correctly handling backlog processing is a common task
in the crypto API implementation and outside users of it.
This patch adds a generic implementation for doing so in
preparation for using it across the board instead of hand
rolled versions.
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
CC: Eric Biggers <ebiggers3@gmail.com>
CC: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fix up affected files that include this signal functionality via sched.h.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently all bits not set in mask are cleared in crypto_larval_lookup.
This is unnecessary as wherever the type bits are used it is always
masked anyway.
This patch removes the clearing so that we may use bits set in the
type but not in the mask for special purposes, e.g., picking up
internal algorithms.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto_exit_cipher_ops() and crypto_exit_compress_ops() are no-ops and
have been for a long time, so remove them.
Signed-off-by: Eric Biggers <ebiggers@google.com>
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>
Several hardware related cipher implementations are implemented as
follows: a "helper" cipher implementation is registered with the
kernel crypto API.
Such helper ciphers are never intended to be called by normal users. In
some cases, calling them via the normal crypto API may even cause
failures including kernel crashes. In a normal case, the "wrapping"
ciphers that use the helpers ensure that these helpers are invoked
such that they cannot cause any calamity.
Considering the AF_ALG user space interface, unprivileged users can
call all ciphers registered with the crypto API, including these
helper ciphers that are not intended to be called directly. That
means, with AF_ALG user space may invoke these helper ciphers
and may cause undefined states or side effects.
To avoid any potential side effects with such helpers, the patch
prevents the helpers to be called directly. A new cipher type
flag is added: CRYPTO_ALG_INTERNAL. This flag shall be used
to mark helper ciphers. These ciphers can only be used if the
caller invoke the cipher with CRYPTO_ALG_INTERNAL in the type and
mask field.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This prefixes all crypto module loading with "crypto-" so we never run
the risk of exposing module auto-loading to userspace via a crypto API,
as demonstrated by Mathias Krause:
https://lkml.org/lkml/2013/3/4/70
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto_larval_lookup should only return a larval if it created one.
Any larval created by another entity must be processed through
crypto_larval_wait before being returned.
Otherwise this will lead to a larval being killed twice, which
will most likely lead to a crash.
Cc: stable@vger.kernel.org
Reported-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
On Thu, Jun 20, 2013 at 10:00:21AM +0200, Daniel Borkmann wrote:
> After having fixed a NULL pointer dereference in SCTP 1abd165e ("net:
> sctp: fix NULL pointer dereference in socket destruction"), I ran into
> the following NULL pointer dereference in the crypto subsystem with
> the same reproducer, easily hit each time:
>
> BUG: unable to handle kernel NULL pointer dereference at (null)
> IP: [<ffffffff81070321>] __wake_up_common+0x31/0x90
> PGD 0
> Oops: 0000 [#1] SMP
> Modules linked in: padlock_sha(F-) sha256_generic(F) sctp(F) libcrc32c(F) [..]
> CPU: 6 PID: 3326 Comm: cryptomgr_probe Tainted: GF 3.10.0-rc5+ #1
> Hardware name: Dell Inc. PowerEdge T410/0H19HD, BIOS 1.6.3 02/01/2011
> task: ffff88007b6cf4e0 ti: ffff88007b7cc000 task.ti: ffff88007b7cc000
> RIP: 0010:[<ffffffff81070321>] [<ffffffff81070321>] __wake_up_common+0x31/0x90
> RSP: 0018:ffff88007b7cde08 EFLAGS: 00010082
> RAX: ffffffffffffffe8 RBX: ffff88003756c130 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff88003756c130
> RBP: ffff88007b7cde48 R08: 0000000000000000 R09: ffff88012b173200
> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000282
> R13: ffff88003756c138 R14: 0000000000000000 R15: 0000000000000000
> FS: 0000000000000000(0000) GS:ffff88012fc60000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> CR2: 0000000000000000 CR3: 0000000001a0b000 CR4: 00000000000007e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Stack:
> ffff88007b7cde28 0000000300000000 ffff88007b7cde28 ffff88003756c130
> 0000000000000282 ffff88003756c128 ffffffff81227670 0000000000000000
> ffff88007b7cde78 ffffffff810722b7 ffff88007cdcf000 ffffffff81a90540
> Call Trace:
> [<ffffffff81227670>] ? crypto_alloc_pcomp+0x20/0x20
> [<ffffffff810722b7>] complete_all+0x47/0x60
> [<ffffffff81227708>] cryptomgr_probe+0x98/0xc0
> [<ffffffff81227670>] ? crypto_alloc_pcomp+0x20/0x20
> [<ffffffff8106760e>] kthread+0xce/0xe0
> [<ffffffff81067540>] ? kthread_freezable_should_stop+0x70/0x70
> [<ffffffff815450dc>] ret_from_fork+0x7c/0xb0
> [<ffffffff81067540>] ? kthread_freezable_should_stop+0x70/0x70
> Code: 41 56 41 55 41 54 53 48 83 ec 18 66 66 66 66 90 89 75 cc 89 55 c8
> 4c 8d 6f 08 48 8b 57 08 41 89 cf 4d 89 c6 48 8d 42 e
> RIP [<ffffffff81070321>] __wake_up_common+0x31/0x90
> RSP <ffff88007b7cde08>
> CR2: 0000000000000000
> ---[ end trace b495b19270a4d37e ]---
>
> My assumption is that the following is happening: the minimal SCTP
> tool runs under ``echo 1 > /proc/sys/net/sctp/auth_enable'', hence
> it's making use of crypto_alloc_hash() via sctp_auth_init_hmacs().
> It forks itself, heavily allocates, binds, listens and waits in
> accept on sctp sockets, and then randomly kills some of them (no
> need for an actual client in this case to hit this). Then, again,
> allocating, binding, etc, and then killing child processes.
>
> The problem that might be happening here is that cryptomgr requests
> the module to probe/load through cryptomgr_schedule_probe(), but
> before the thread handler cryptomgr_probe() returns, we return from
> the wait_for_completion_interruptible() function and probably already
> have cleared up larval, thus we run into a NULL pointer dereference
> when in cryptomgr_probe() complete_all() is being called.
>
> If we wait with wait_for_completion() instead, this panic will not
> occur anymore. This is valid, because in case a signal is pending,
> cryptomgr_probe() returns from probing anyway with properly calling
> complete_all().
The use of wait_for_completion_interruptible is intentional so that
we don't lock up the thread if a bug causes us to never wake up.
This bug is caused by the helper thread using the larval without
holding a reference count on it. If the helper thread completes
after the original thread requesting for help has gone away and
destroyed the larval, then we get the crash above.
So the fix is to hold a reference count on the larval.
Cc: <stable@vger.kernel.org> # 3.6+
Reported-by: Daniel Borkmann <dborkman@redhat.com>
Tested-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
As the extsize and init_tfm functions belong to the frontend the
frontend argument is superfluous.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch removes the implementation of hash and digest now that
no algorithms use them anymore. The interface though will remain
until the users are converted across.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds the helper crypto_attr_alg2 which is similar to
crypto_attr_alg but takes an extra frontend argument. This is
intended to be used by new style algorithm types such as shash.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Besdies, for the old code, gcc-4.3.3 produced this warning:
"format not a string literal and no format arguments"
Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
