linux-toradex.git/crypto/algapi.c, branch v5.12-rc7

crypto: algapi - use common mechanism for inheriting flags

2020-07-16T11:49:08+00:00

The flag CRYPTO_ALG_ASYNC is "inherited" in the sense that when a
template is instantiated, the template will have CRYPTO_ALG_ASYNC set if
any of the algorithms it uses has CRYPTO_ALG_ASYNC set.

We'd like to add a second flag (CRYPTO_ALG_ALLOCATES_MEMORY) that gets
"inherited" in the same way.  This is difficult because the handling of
CRYPTO_ALG_ASYNC is hardcoded everywhere.  Address this by:

  - Add CRYPTO_ALG_INHERITED_FLAGS, which contains the set of flags that
    have these inheritance semantics.

  - Add crypto_algt_inherited_mask(), for use by template ->create()
    methods.  It returns any of these flags that the user asked to be
    unset and thus must be passed in the 'mask' to crypto_grab_*().

  - Also modify crypto_check_attr_type() to handle computing the 'mask'
    so that most templates can just use this.

  - Make crypto_grab_*() propagate these flags to the template instance
    being created so that templates don't have to do this themselves.

Make crypto/simd.c propagate these flags too, since it "wraps" another
algorithm, similar to a template.

Based on a patch by Mikulas Patocka 
(https://lore.kernel.org/r/alpine.LRH.2.02.2006301414580.30526@file01.intranet.prod.int.rdu2.redhat.com).

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: algapi - create function to add request in front of queue

2020-05-08T05:30:40+00:00

Add crypto_enqueue_request_head function that enqueues a
request in front of queue.
This will be used in crypto-engine, on error path. In case a request
was not executed by hardware, enqueue it back in front of queue (to
keep the order of requests).

Signed-off-by: Iuliana Prodan 
Signed-off-by: Herbert Xu

crypto: api - Fix use-after-free and race in crypto_spawn_alg

2020-04-16T06:49:22+00:00

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: 4f87ee118d16 ("crypto: api - Do not zap spawn->alg")
Fixes: 73669cc55646 ("crypto: api - Fix race condition in...")
Cc: 
Signed-off-by: Herbert Xu

crypto: algapi - Avoid spurious modprobe on LOADED

2020-04-16T06:49:22+00:00

Currently after any algorithm is registered and tested, there's an
unnecessary request_module("cryptomgr") even if it's already loaded.
Also, CRYPTO_MSG_ALG_LOADED is sent twice, and thus if the algorithm is
"crct10dif", lib/crc-t10dif.c replaces the tfm twice rather than once.

This occurs because CRYPTO_MSG_ALG_LOADED is sent using
crypto_probing_notify(), which tries to load "cryptomgr" if the
notification is not handled (NOTIFY_DONE).  This doesn't make sense
because "cryptomgr" doesn't handle this notification.

Fix this by using crypto_notify() instead of crypto_probing_notify().

Fixes: dd8b083f9a5e ("crypto: api - Introduce notifier for new crypto algorithms")
Cc:  # v4.20+
Cc: Martin K. Petersen 
Signed-off-by: Eric Biggers 
Reviewed-by: Martin K. Petersen 
Signed-off-by: Herbert Xu

crypto: algapi - remove crypto_template::{alloc,free}()

2020-01-09T03:30:58+00:00

Now that all templates provide a ->create() method which creates an
instance, installs a strongly-typed ->free() method directly to it, and
registers it, the older ->alloc() and ->free() methods in
'struct crypto_template' are no longer used.  Remove them.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: algapi - fold crypto_init_spawn() into crypto_grab_spawn()

2020-01-09T03:30:57+00:00

Now that crypto_init_spawn() is only called by crypto_grab_spawn(),
simplify things by moving its functionality into crypto_grab_spawn().

In the process of doing this, also be more consistent about when the
spawn and instance are updated, and remove the crypto_spawn::dropref
flag since now it's always set.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: algapi - remove obsoleted instance creation helpers

2020-01-09T03:30:57+00:00

Remove lots of helper functions that were previously used for
instantiating crypto templates, but are now unused:

- crypto_get_attr_alg() and similar functions looked up an inner
  algorithm directly from a template parameter.  These were replaced
  with getting the algorithm's name, then calling crypto_grab_*().

- crypto_init_spawn2() and similar functions initialized a spawn, given
  an algorithm.  Similarly, these were replaced with crypto_grab_*().

- crypto_alloc_instance() and similar functions allocated an instance
  with a single spawn, given the inner algorithm.  These aren't useful
  anymore since crypto_grab_*() need the instance allocated first.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: algapi - pass instance to crypto_grab_spawn()

2020-01-09T03:30:54+00:00

Currently, crypto_spawn::inst is first used temporarily to pass the
instance to crypto_grab_spawn().  Then crypto_init_spawn() overwrites it
with crypto_spawn::next, which shares the same union.  Finally,
crypto_spawn::inst is set again when the instance is registered.

Make this less convoluted by just passing the instance as an argument to
crypto_grab_spawn() instead.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: algapi - make crypto_grab_spawn() handle an ERR_PTR() name

2020-01-09T03:30:53+00:00

To allow further simplifying template ->create() functions, make
crypto_grab_spawn() handle an ERR_PTR() name by passing back the error.

For most templates, this will allow the result of crypto_attr_alg_name()
to be passed directly to crypto_grab_*(), rather than first having to
assign it to a variable [where it can then potentially be misused, as it
was in the rfc7539 template prior to commit 5e27f38f1f3f ("crypto:
chacha20poly1305 - set cra_name correctly")] and check it for error.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: algapi - make crypto_drop_spawn() a no-op on uninitialized spawns

2020-01-09T03:30:53+00:00

Make crypto_drop_spawn() do nothing when the spawn hasn't been
initialized with an algorithm yet.  This will allow simplifying error
handling in all the template ->create() functions, since on error they
will be able to just call their usual "free instance" function, rather
than having to handle dropping just the spawns that have been
initialized so far.

This does assume the spawn starts out zero-filled, but that's always the
case since instances are allocated with kzalloc().  And some other code
already assumes this anyway.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu