linux-stable.git/crypto, branch v5.1.4

crypto: gcm - fix incompatibility between "gcm" and "gcm_base"

2019-05-22T05:39:44+00:00

commit f699594d436960160f6d5ba84ed4a222f20d11cd upstream.

GCM instances can be created by either the "gcm" template, which only
allows choosing the block cipher, e.g. "gcm(aes)"; or by "gcm_base",
which allows choosing the ctr and ghash implementations, e.g.
"gcm_base(ctr(aes-generic),ghash-generic)".

However, a "gcm_base" instance prevents a "gcm" instance from being
registered using the same implementations.  Nor will the instance be
found by lookups of "gcm".  This can be used as a denial of service.
Moreover, "gcm_base" instances are never tested by the crypto
self-tests, even if there are compatible "gcm" tests.

The root cause of these problems is that instances of the two templates
use different cra_names.  Therefore, fix these problems by making
"gcm_base" instances set the same cra_name as "gcm" instances, e.g.
"gcm(aes)" instead of "gcm_base(ctr(aes-generic),ghash-generic)".

This requires extracting the block cipher name from the name of the ctr
algorithm.  It also requires starting to verify that the algorithms are
really ctr and ghash, not something else entirely.  But it would be
bizarre if anyone were actually using non-gcm-compatible algorithms with
gcm_base, so this shouldn't break anyone in practice.

Fixes: d00aa19b507b ("[CRYPTO] gcm: Allow block cipher parameter")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: crct10dif-generic - fix use via crypto_shash_digest()

2019-05-22T05:39:43+00:00

commit 307508d1072979f4435416f87936f87eaeb82054 upstream.

The ->digest() method of crct10dif-generic reads the current CRC value
from the shash_desc context.  But this value is uninitialized, causing
crypto_shash_digest() to compute the wrong result.  Fix it.

Probably this wasn't noticed before because lib/crc-t10dif.c only uses
crypto_shash_update(), not crypto_shash_digest().  Likewise,
crypto_shash_digest() is not yet tested by the crypto self-tests because
those only test the ahash API which only uses shash init/update/final.

This bug was detected by my patches that improve testmgr to fuzz
algorithms against their generic implementation.

Fixes: 2d31e518a428 ("crypto: crct10dif - Wrap crc_t10dif function all to use crypto transform framework")
Cc:  # v3.11+
Cc: Tim Chen 
Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: skcipher - don't WARN on unprocessed data after slow walk step

2019-05-22T05:39:43+00:00

commit dcaca01a42cc2c425154a13412b4124293a6e11e upstream.

skcipher_walk_done() assumes it's a bug if, after the "slow" path is
executed where the next chunk of data is processed via a bounce buffer,
the algorithm says it didn't process all bytes.  Thus it WARNs on this.

However, this can happen legitimately when the message needs to be
evenly divisible into "blocks" but isn't, and the algorithm has a
'walksize' greater than the block size.  For example, ecb-aes-neonbs
sets 'walksize' to 128 bytes and only supports messages evenly divisible
into 16-byte blocks.  If, say, 17 message bytes remain but they straddle
scatterlist elements, the skcipher_walk code will take the "slow" path
and pass the algorithm all 17 bytes in the bounce buffer.  But the
algorithm will only be able to process 16 bytes, triggering the WARN.

Fix this by just removing the WARN_ON().  Returning -EINVAL, as the code
already does, is the right behavior.

This bug was detected by my patches that improve testmgr to fuzz
algorithms against their generic implementation.

Fixes: b286d8b1a690 ("crypto: skcipher - Add skcipher walk interface")
Cc:  # v4.10+
Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: ccm - fix incompatibility between "ccm" and "ccm_base"

2019-05-22T05:39:42+00:00

commit 6a1faa4a43f5fabf9cbeaa742d916e7b5e73120f upstream.

CCM instances can be created by either the "ccm" template, which only
allows choosing the block cipher, e.g. "ccm(aes)"; or by "ccm_base",
which allows choosing the ctr and cbcmac implementations, e.g.
"ccm_base(ctr(aes-generic),cbcmac(aes-generic))".

However, a "ccm_base" instance prevents a "ccm" instance from being
registered using the same implementations.  Nor will the instance be
found by lookups of "ccm".  This can be used as a denial of service.
Moreover, "ccm_base" instances are never tested by the crypto
self-tests, even if there are compatible "ccm" tests.

The root cause of these problems is that instances of the two templates
use different cra_names.  Therefore, fix these problems by making
"ccm_base" instances set the same cra_name as "ccm" instances, e.g.
"ccm(aes)" instead of "ccm_base(ctr(aes-generic),cbcmac(aes-generic))".

This requires extracting the block cipher name from the name of the ctr
and cbcmac algorithms.  It also requires starting to verify that the
algorithms are really ctr and cbcmac using the same block cipher, not
something else entirely.  But it would be bizarre if anyone were
actually using non-ccm-compatible algorithms with ccm_base, so this
shouldn't break anyone in practice.

Fixes: 4a49b499dfa0 ("[CRYPTO] ccm: Added CCM mode")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: chacha20poly1305 - set cra_name correctly

2019-05-22T05:39:42+00:00

commit 5e27f38f1f3f45a0c938299c3a34a2d2db77165a upstream.

If the rfc7539 template is instantiated with specific implementations,
e.g. "rfc7539(chacha20-generic,poly1305-generic)" rather than
"rfc7539(chacha20,poly1305)", then the implementation names end up
included in the instance's cra_name.  This is incorrect because it then
prevents all users from allocating "rfc7539(chacha20,poly1305)", if the
highest priority implementations of chacha20 and poly1305 were selected.
Also, the self-tests aren't run on an instance allocated in this way.

Fix it by setting the instance's cra_name from the underlying
algorithms' actual cra_names, rather than from the requested names.
This matches what other templates do.

Fixes: 71ebc4d1b27d ("crypto: chacha20poly1305 - Add a ChaCha20-Poly1305 AEAD construction, RFC7539")
Cc:  # v4.2+
Cc: Martin Willi 
Signed-off-by: Eric Biggers 
Reviewed-by: Martin Willi 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: chacha-generic - fix use as arm64 no-NEON fallback

2019-05-22T05:39:42+00:00

commit 7aceaaef04eaaf6019ca159bc354d800559bba1d upstream.

The arm64 implementations of ChaCha and XChaCha are failing the extra
crypto self-tests following my patches to test the !may_use_simd() code
paths, which previously were untested.  The problem is as follows:

When !may_use_simd(), the arm64 NEON implementations fall back to the
generic implementation, which uses the skcipher_walk API to iterate
through the src/dst scatterlists.  Due to how the skcipher_walk API
works, walk.stride is set from the skcipher_alg actually being used,
which in this case is the arm64 NEON algorithm.  Thus walk.stride is
5*CHACHA_BLOCK_SIZE, not CHACHA_BLOCK_SIZE.

This unnecessarily large stride shouldn't cause an actual problem.
However, the generic implementation computes round_down(nbytes,
walk.stride).  round_down() assumes the round amount is a power of 2,
which 5*CHACHA_BLOCK_SIZE is not, so it gives the wrong result.

This causes the following case in skcipher_walk_done() to be hit,
causing a WARN() and failing the encryption operation:

	if (WARN_ON(err)) {
		/* unexpected case; didn't process all bytes */
		err = -EINVAL;
		goto finish;
	}

Fix it by rounding down to CHACHA_BLOCK_SIZE instead of walk.stride.

(Or we could replace round_down() with rounddown(), but that would add a
slow division operation every time, which I think we should avoid.)

Fixes: 2fe55987b262 ("crypto: arm64/chacha - use combined SIMD/ALU routine for more speed")
Cc:  # v5.0+
Signed-off-by: Eric Biggers 
Reviewed-by: Ard Biesheuvel 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: lrw - don't access already-freed walk.iv

2019-05-22T05:39:41+00:00

commit aec286cd36eacfd797e3d5dab8d5d23c15d1bb5e upstream.

If the user-provided IV needs to be aligned to the algorithm's
alignmask, then skcipher_walk_virt() copies the IV into a new aligned
buffer walk.iv.  But skcipher_walk_virt() can fail afterwards, and then
if the caller unconditionally accesses walk.iv, it's a use-after-free.

Fix this in the LRW template by checking the return value of
skcipher_walk_virt().

This bug was detected by my patches that improve testmgr to fuzz
algorithms against their generic implementation.  When the extra
self-tests were run on a KASAN-enabled kernel, a KASAN use-after-free
splat occured during lrw(aes) testing.

Fixes: c778f96bf347 ("crypto: lrw - Optimize tweak computation")
Cc:  # v4.20+
Cc: Ondrej Mosnacek 
Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: salsa20 - don't access already-freed walk.iv

2019-05-22T05:39:41+00:00

commit edaf28e996af69222b2cb40455dbb5459c2b875a upstream.

If the user-provided IV needs to be aligned to the algorithm's
alignmask, then skcipher_walk_virt() copies the IV into a new aligned
buffer walk.iv.  But skcipher_walk_virt() can fail afterwards, and then
if the caller unconditionally accesses walk.iv, it's a use-after-free.

salsa20-generic doesn't set an alignmask, so currently it isn't affected
by this despite unconditionally accessing walk.iv.  However this is more
subtle than desired, and it was actually broken prior to the alignmask
being removed by commit b62b3db76f73 ("crypto: salsa20-generic - cleanup
and convert to skcipher API").

Since salsa20-generic does not update the IV and does not need any IV
alignment, update it to use req->iv instead of walk.iv.

Fixes: 2407d60872dd ("[CRYPTO] salsa20: Salsa20 stream cipher")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: lrw - Fix atomic sleep when walking skcipher

2019-04-18T14:13:46+00:00

When we perform a walk in the completion function, we need to ensure
that it is atomic.

Fixes: ac3c8f36c31d ("crypto: lrw - Do not use auxiliary buffer")
Cc: 
Signed-off-by: Herbert Xu 
Acked-by: Ondrej Mosnacek 
Signed-off-by: Herbert Xu

crypto: xts - Fix atomic sleep when walking skcipher

2019-04-18T14:13:46+00:00

When we perform a walk in the completion function, we need to ensure
that it is atomic.

Reported-by: syzbot+6f72c20560060c98b566@syzkaller.appspotmail.com
Fixes: 78105c7e769b ("crypto: xts - Drop use of auxiliary buffer")
Cc: 
Signed-off-by: Herbert Xu 
Acked-by: Ondrej Mosnacek 
Signed-off-by: Herbert Xu