linux-toradex.git/crypto/pcrypt.c, branch v5.19-rc8

crypto: pcrypt - Delay write to padata->info

2021-10-29T13:04:04+00:00

These three events can race when pcrypt is used multiple times in a
template ("pcrypt(pcrypt(...))"):

  1.  [taskA] The caller makes the crypto request via crypto_aead_encrypt()
  2.  [kworkerB] padata serializes the inner pcrypt request
  3.  [kworkerC] padata serializes the outer pcrypt request

3 might finish before the call to crypto_aead_encrypt() returns in 1,
resulting in two possible issues.

First, a use-after-free of the crypto request's memory when, for
example, taskA writes to the outer pcrypt request's padata->info in
pcrypt_aead_enc() after kworkerC completes the request.

Second, the outer pcrypt request overwrites the inner pcrypt request's
return code with -EINPROGRESS, making a successful request appear to
fail.  For instance, kworkerB writes the outer pcrypt request's
padata->info in pcrypt_aead_done() and then taskA overwrites it
in pcrypt_aead_enc().

Avoid both situations by delaying the write of padata->info until after
the inner crypto request's return code is checked.  This prevents the
use-after-free by not touching the crypto request's memory after the
next-inner crypto request is made, and stops padata->info from being
overwritten.

Fixes: 5068c7a883d16 ("crypto: pcrypt - Add pcrypt crypto parallelization wrapper")
Reported-by: syzbot+b187b77c8474f9648fae@syzkaller.appspotmail.com
Signed-off-by: Daniel Jordan 
Signed-off-by: Herbert Xu

padata: fold padata_alloc_possible() into padata_alloc()

2020-07-23T07:34:18+00:00

There's no reason to have two interfaces when there's only one caller.
Removing _possible saves text and simplifies future changes.

Signed-off-by: Daniel Jordan 
Cc: Herbert Xu 
Cc: Steffen Klassert 
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu

padata: remove stop function

2020-07-23T07:34:18+00:00

padata_stop() has two callers and is unnecessary in both cases.  When
pcrypt calls it before padata_free(), it's being unloaded so there are
no outstanding padata jobs[0].  When __padata_free() calls it, it's
either along the same path or else pcrypt initialization failed, which
of course means there are also no outstanding jobs.

Removing it simplifies padata and saves text.

[0] https://lore.kernel.org/linux-crypto/20191119225017.mjrak2fwa5vccazl@gondor.apana.org.au/

Signed-off-by: Daniel Jordan 
Cc: Herbert Xu 
Cc: Steffen Klassert 
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu

padata: remove start function

2020-07-23T07:34:17+00:00

padata_start() is only used right after pcrypt allocates an instance
with all possible CPUs, when PADATA_INVALID can't happen, so there's no
need for a separate "start" step.  It can be done during allocation to
save text, make using padata easier, and avoid unneeded calls in the
future.

Signed-off-by: Daniel Jordan 
Cc: Herbert Xu 
Cc: Steffen Klassert 
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu

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: pcrypt - simplify error handling in pcrypt_create_aead()

2020-03-06T01:28:24+00:00

Simplify the error handling in pcrypt_create_aead() by taking advantage
of crypto_grab_aead() now handling an ERR_PTR() name and by taking
advantage of crypto_drop_aead() now accepting (as a no-op) a spawn that
hasn't been grabbed yet.

This required also making padata_free_shell() accept a NULL argument.

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

crypto: aead - pass instance to crypto_grab_aead()

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

Initializing a crypto_aead_spawn currently requires:

1. Set spawn->base.inst to point to the instance.
2. Call crypto_grab_aead().

But there's no reason for these steps to be separate, and in fact this
unneeded complication has caused at least one bug, the one fixed by
commit 6db43410179b ("crypto: adiantum - initialize crypto_spawn::inst")

So just make crypto_grab_aead() take the instance as an argument.

To keep the function calls from getting too unwieldy due to this extra
argument, also introduce a 'mask' variable into the affected places
which weren't already using one.

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

padata: remove cpumask change notifier

2019-12-11T08:37:02+00:00

Since commit 63d3578892dc ("crypto: pcrypt - remove padata cpumask
notifier") this feature is unused, so get rid of it.

Signed-off-by: Daniel Jordan 
Cc: Eric Biggers 
Cc: Herbert Xu 
Cc: Jonathan Corbet 
Cc: Steffen Klassert 
Cc: linux-crypto@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu

crypto: pcrypt - Do not clear MAY_SLEEP flag in original request

2019-12-11T08:36:55+00:00

We should not be modifying the original request's MAY_SLEEP flag
upon completion.  It makes no sense to do so anyway.

Reported-by: Eric Biggers 
Fixes: 5068c7a883d1 ("crypto: pcrypt - Add pcrypt crypto...")
Signed-off-by: Herbert Xu 
Tested-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: pcrypt - Avoid deadlock by using per-instance padata queues

2019-12-11T08:36:45+00:00

If the pcrypt template is used multiple times in an algorithm, then a
deadlock occurs because all pcrypt instances share the same
padata_instance, which completes requests in the order submitted.  That
is, the inner pcrypt request waits for the outer pcrypt request while
the outer request is already waiting for the inner.

This patch fixes this by allocating a set of queues for each pcrypt
instance instead of using two global queues.  In order to maintain
the existing user-space interface, the pinst structure remains global
so any sysfs modifications will apply to every pcrypt instance.

Note that when an update occurs we have to allocate memory for
every pcrypt instance.  Should one of the allocations fail we
will abort the update without rolling back changes already made.

The new per-instance data structure is called padata_shell and is
essentially a wrapper around parallel_data.

Reproducer:

	#include 
	#include 
	#include 

	int main()
	{
		struct sockaddr_alg addr = {
			.salg_type = "aead",
			.salg_name = "pcrypt(pcrypt(rfc4106-gcm-aesni))"
		};
		int algfd, reqfd;
		char buf[32] = { 0 };

		algfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
		bind(algfd, (void *)&addr, sizeof(addr));
		setsockopt(algfd, SOL_ALG, ALG_SET_KEY, buf, 20);
		reqfd = accept(algfd, 0, 0);
		write(reqfd, buf, 32);
		read(reqfd, buf, 16);
	}

Reported-by: syzbot+56c7151cad94eec37c521f0e47d2eee53f9361c4@syzkaller.appspotmail.com
Fixes: 5068c7a883d1 ("crypto: pcrypt - Add pcrypt crypto parallelization wrapper")
Signed-off-by: Herbert Xu 
Tested-by: Eric Biggers 
Signed-off-by: Herbert Xu