<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/crypto, branch v3.16.80</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>crypto: user - fix memory leak in crypto_report</title>
<updated>2019-12-10T18:01:32+00:00</updated>
<author>
<name>Navid Emamdoost</name>
<email>navid.emamdoost@gmail.com</email>
</author>
<published>2019-10-04T19:29:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=52373b487ee420c43e1d9d01b4b8c11bb6e9bdbf'/>
<id>52373b487ee420c43e1d9d01b4b8c11bb6e9bdbf</id>
<content type='text'>
commit ffdde5932042600c6807d46c1550b28b0db6a3bc upstream.

In crypto_report, a new skb is created via nlmsg_new(). This skb should
be released if crypto_report_alg() fails.

Fixes: a38f7907b926 ("crypto: Add userspace configuration API")
Signed-off-by: Navid Emamdoost &lt;navid.emamdoost@gmail.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
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<pre>
commit ffdde5932042600c6807d46c1550b28b0db6a3bc upstream.

In crypto_report, a new skb is created via nlmsg_new(). This skb should
be released if crypto_report_alg() fails.

Fixes: a38f7907b926 ("crypto: Add userspace configuration API")
Signed-off-by: Navid Emamdoost &lt;navid.emamdoost@gmail.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>crypto: user - Fix crypto_alg_match race</title>
<updated>2019-12-10T18:01:32+00:00</updated>
<author>
<name>Herbert Xu</name>
<email>herbert@gondor.apana.org.au</email>
</author>
<published>2015-04-07T13:27:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=ea8e4f792da5652f23481231e252f06221b73445'/>
<id>ea8e4f792da5652f23481231e252f06221b73445</id>
<content type='text'>
commit 016baaa1183bb0c5fb2a7de42413bba8a51c1bc8 upstream.

The function crypto_alg_match returns an algorithm without taking
any references on it.  This means that the algorithm can be freed
at any time, therefore all users of crypto_alg_match are buggy.

This patch fixes this by taking a reference count on the algorithm
to prevent such races.

Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 016baaa1183bb0c5fb2a7de42413bba8a51c1bc8 upstream.

The function crypto_alg_match returns an algorithm without taking
any references on it.  This means that the algorithm can be freed
at any time, therefore all users of crypto_alg_match are buggy.

This patch fixes this by taking a reference count on the algorithm
to prevent such races.

Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>crypto: ghash - fix unaligned memory access in ghash_setkey()</title>
<updated>2019-10-31T22:14:52+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2019-05-30T17:50:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=9ac9eeca2c06155e2198ee15ea96ccf7c85e477c'/>
<id>9ac9eeca2c06155e2198ee15ea96ccf7c85e477c</id>
<content type='text'>
commit 5c6bc4dfa515738149998bb0db2481a4fdead979 upstream.

Changing ghash_mod_init() to be subsys_initcall made it start running
before the alignment fault handler has been installed on ARM.  In kernel
builds where the keys in the ghash test vectors happened to be
misaligned in the kernel image, this exposed the longstanding bug that
ghash_setkey() is incorrectly casting the key buffer (which can have any
alignment) to be128 for passing to gf128mul_init_4k_lle().

Fix this by memcpy()ing the key to a temporary buffer.

Don't fix it by setting an alignmask on the algorithm instead because
that would unnecessarily force alignment of the data too.

Fixes: 2cdc6899a88e ("crypto: ghash - Add GHASH digest algorithm for GCM")
Reported-by: Peter Robinson &lt;pbrobinson@gmail.com&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Tested-by: Peter Robinson &lt;pbrobinson@gmail.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5c6bc4dfa515738149998bb0db2481a4fdead979 upstream.

Changing ghash_mod_init() to be subsys_initcall made it start running
before the alignment fault handler has been installed on ARM.  In kernel
builds where the keys in the ghash test vectors happened to be
misaligned in the kernel image, this exposed the longstanding bug that
ghash_setkey() is incorrectly casting the key buffer (which can have any
alignment) to be128 for passing to gf128mul_init_4k_lle().

Fix this by memcpy()ing the key to a temporary buffer.

Don't fix it by setting an alignmask on the algorithm instead because
that would unnecessarily force alignment of the data too.

Fixes: 2cdc6899a88e ("crypto: ghash - Add GHASH digest algorithm for GCM")
Reported-by: Peter Robinson &lt;pbrobinson@gmail.com&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Tested-by: Peter Robinson &lt;pbrobinson@gmail.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>crypto: user - prevent operating on larval algorithms</title>
<updated>2019-10-05T15:20:08+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2019-07-02T21:17:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=4d8a6e79c53c3ffd2bb794f94006f0ef856020fd'/>
<id>4d8a6e79c53c3ffd2bb794f94006f0ef856020fd</id>
<content type='text'>
commit 21d4120ec6f5b5992b01b96ac484701163917b63 upstream.

Michal Suchanek reported [1] that running the pcrypt_aead01 test from
LTP [2] in a loop and holding Ctrl-C causes a NULL dereference of
alg-&gt;cra_users.next in crypto_remove_spawns(), via crypto_del_alg().
The test repeatedly uses CRYPTO_MSG_NEWALG and CRYPTO_MSG_DELALG.

The crash occurs when the instance that CRYPTO_MSG_DELALG is trying to
unregister isn't a real registered algorithm, but rather is a "test
larval", which is a special "algorithm" added to the algorithms list
while the real algorithm is still being tested.  Larvals don't have
initialized cra_users, so that causes the crash.  Normally pcrypt_aead01
doesn't trigger this because CRYPTO_MSG_NEWALG waits for the algorithm
to be tested; however, CRYPTO_MSG_NEWALG returns early when interrupted.

Everything else in the "crypto user configuration" API has this same bug
too, i.e. it inappropriately allows operating on larval algorithms
(though it doesn't look like the other cases can cause a crash).

Fix this by making crypto_alg_match() exclude larval algorithms.

[1] https://lkml.kernel.org/r/20190625071624.27039-1-msuchanek@suse.de
[2] https://github.com/linux-test-project/ltp/blob/20190517/testcases/kernel/crypto/pcrypt_aead01.c

Reported-by: Michal Suchanek &lt;msuchanek@suse.de&gt;
Fixes: a38f7907b926 ("crypto: Add userspace configuration API")
Cc: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 21d4120ec6f5b5992b01b96ac484701163917b63 upstream.

Michal Suchanek reported [1] that running the pcrypt_aead01 test from
LTP [2] in a loop and holding Ctrl-C causes a NULL dereference of
alg-&gt;cra_users.next in crypto_remove_spawns(), via crypto_del_alg().
The test repeatedly uses CRYPTO_MSG_NEWALG and CRYPTO_MSG_DELALG.

The crash occurs when the instance that CRYPTO_MSG_DELALG is trying to
unregister isn't a real registered algorithm, but rather is a "test
larval", which is a special "algorithm" added to the algorithms list
while the real algorithm is still being tested.  Larvals don't have
initialized cra_users, so that causes the crash.  Normally pcrypt_aead01
doesn't trigger this because CRYPTO_MSG_NEWALG waits for the algorithm
to be tested; however, CRYPTO_MSG_NEWALG returns early when interrupted.

Everything else in the "crypto user configuration" API has this same bug
too, i.e. it inappropriately allows operating on larval algorithms
(though it doesn't look like the other cases can cause a crash).

Fix this by making crypto_alg_match() exclude larval algorithms.

[1] https://lkml.kernel.org/r/20190625071624.27039-1-msuchanek@suse.de
[2] https://github.com/linux-test-project/ltp/blob/20190517/testcases/kernel/crypto/pcrypt_aead01.c

Reported-by: Michal Suchanek &lt;msuchanek@suse.de&gt;
Fixes: a38f7907b926 ("crypto: Add userspace configuration API")
Cc: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>crypto: salsa20 - don't access already-freed walk.iv</title>
<updated>2019-09-23T20:11:44+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2019-04-10T06:46:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=db8028988b418caecb05cd63d1ef43d8133b4bd4'/>
<id>db8028988b418caecb05cd63d1ef43d8133b4bd4</id>
<content type='text'>
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-&gt;iv instead of walk.iv.

Fixes: 2407d60872dd ("[CRYPTO] salsa20: Salsa20 stream cipher")
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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-&gt;iv instead of walk.iv.

Fixes: 2407d60872dd ("[CRYPTO] salsa20: Salsa20 stream cipher")
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>crypto: crct10dif-generic - fix use via crypto_shash_digest()</title>
<updated>2019-09-23T20:11:39+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2019-03-31T20:04:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=00c649ff2e87add15d293ca6c52180b215b8a4bd'/>
<id>00c649ff2e87add15d293ca6c52180b215b8a4bd</id>
<content type='text'>
commit 307508d1072979f4435416f87936f87eaeb82054 upstream.

The -&gt;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: Tim Chen &lt;tim.c.chen@linux.intel.com&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 307508d1072979f4435416f87936f87eaeb82054 upstream.

The -&gt;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: Tim Chen &lt;tim.c.chen@linux.intel.com&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>crypto: ahash - fix another early termination in hash walk</title>
<updated>2019-07-09T21:03:55+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2019-02-01T07:51:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=d1bc1078ee8a282b3902ceef35484d8c3b01d4a0'/>
<id>d1bc1078ee8a282b3902ceef35484d8c3b01d4a0</id>
<content type='text'>
commit 77568e535af7c4f97eaef1e555bf0af83772456c upstream.

Hash algorithms with an alignmask set, e.g. "xcbc(aes-aesni)" and
"michael_mic", fail the improved hash tests because they sometimes
produce the wrong digest.  The bug is that in the case where a
scatterlist element crosses pages, not all the data is actually hashed
because the scatterlist walk terminates too early.  This happens because
the 'nbytes' variable in crypto_hash_walk_done() is assigned the number
of bytes remaining in the page, then later interpreted as the number of
bytes remaining in the scatterlist element.  Fix it.

Fixes: 900a081f6912 ("crypto: ahash - Fix early termination in hash walk")
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 77568e535af7c4f97eaef1e555bf0af83772456c upstream.

Hash algorithms with an alignmask set, e.g. "xcbc(aes-aesni)" and
"michael_mic", fail the improved hash tests because they sometimes
produce the wrong digest.  The bug is that in the case where a
scatterlist element crosses pages, not all the data is actually hashed
because the scatterlist walk terminates too early.  This happens because
the 'nbytes' variable in crypto_hash_walk_done() is assigned the number
of bytes remaining in the page, then later interpreted as the number of
bytes remaining in the scatterlist element.  Fix it.

Fixes: 900a081f6912 ("crypto: ahash - Fix early termination in hash walk")
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>crypto: testmgr - skip crc32c context test for ahash algorithms</title>
<updated>2019-07-09T21:03:52+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2019-01-24T04:57:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=a67f0130ead5b5678c6b5be30b22cc37befbe15f'/>
<id>a67f0130ead5b5678c6b5be30b22cc37befbe15f</id>
<content type='text'>
commit eb5e6730db98fcc4b51148b4a819fa4bf864ae54 upstream.

Instantiating "cryptd(crc32c)" causes a crypto self-test failure because
the crypto_alloc_shash() in alg_test_crc32c() fails.  This is because
cryptd(crc32c) is an ahash algorithm, not a shash algorithm; so it can
only be accessed through the ahash API, unlike shash algorithms which
can be accessed through both the ahash and shash APIs.

As the test is testing the shash descriptor format which is only
applicable to shash algorithms, skip it for ahash algorithms.

(Note that it's still important to fix crypto self-test failures even
 for weird algorithm instantiations like cryptd(crc32c) that no one
 would really use; in fips_enabled mode unprivileged users can use them
 to panic the kernel, and also they prevent treating a crypto self-test
 failure as a bug when fuzzing the kernel.)

Fixes: 8e3ee85e68c5 ("crypto: crc32c - Test descriptor context format")
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit eb5e6730db98fcc4b51148b4a819fa4bf864ae54 upstream.

Instantiating "cryptd(crc32c)" causes a crypto self-test failure because
the crypto_alloc_shash() in alg_test_crc32c() fails.  This is because
cryptd(crc32c) is an ahash algorithm, not a shash algorithm; so it can
only be accessed through the ahash API, unlike shash algorithms which
can be accessed through both the ahash and shash APIs.

As the test is testing the shash descriptor format which is only
applicable to shash algorithms, skip it for ahash algorithms.

(Note that it's still important to fix crypto self-test failures even
 for weird algorithm instantiations like cryptd(crc32c) that no one
 would really use; in fips_enabled mode unprivileged users can use them
 to panic the kernel, and also they prevent treating a crypto self-test
 failure as a bug when fuzzing the kernel.)

Fixes: 8e3ee85e68c5 ("crypto: crc32c - Test descriptor context format")
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>crypto: tgr192 - fix unaligned memory access</title>
<updated>2019-07-09T21:03:48+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2019-01-10T20:17:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=7eadb226baa9915d46e40d934e6e0ca788ca15f0'/>
<id>7eadb226baa9915d46e40d934e6e0ca788ca15f0</id>
<content type='text'>
commit f990f7fb58ac8ac9a43316f09a48cff1a49dda42 upstream.

Fix an unaligned memory access in tgr192_transform() by using the
unaligned access helpers.

Fixes: 06ace7a9bafe ("[CRYPTO] Use standard byte order macros wherever possible")
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f990f7fb58ac8ac9a43316f09a48cff1a49dda42 upstream.

Fix an unaligned memory access in tgr192_transform() by using the
unaligned access helpers.

Fixes: 06ace7a9bafe ("[CRYPTO] Use standard byte order macros wherever possible")
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>crypto: hash - set CRYPTO_TFM_NEED_KEY if -&gt;setkey() fails</title>
<updated>2019-07-09T21:03:48+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2019-01-07T02:47:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=9aa2d96df4fa4f3c875c580aff3bb4d31229003d'/>
<id>9aa2d96df4fa4f3c875c580aff3bb4d31229003d</id>
<content type='text'>
commit ba7d7433a0e998c902132bd47330e355a1eaa894 upstream.

Some algorithms have a -&gt;setkey() method that is not atomic, in the
sense that setting a key can fail after changes were already made to the
tfm context.  In this case, if a key was already set the tfm can end up
in a state that corresponds to neither the old key nor the new key.

It's not feasible to make all -&gt;setkey() methods atomic, especially ones
that have to key multiple sub-tfms.  Therefore, make the crypto API set
CRYPTO_TFM_NEED_KEY if -&gt;setkey() fails and the algorithm requires a
key, to prevent the tfm from being used until a new key is set.

Note: we can't set CRYPTO_TFM_NEED_KEY for OPTIONAL_KEY algorithms, so
-&gt;setkey() for those must nevertheless be atomic.  That's fine for now
since only the crc32 and crc32c algorithms set OPTIONAL_KEY, and it's
not intended that OPTIONAL_KEY be used much.

[Cc stable mainly because when introducing the NEED_KEY flag I changed
 AF_ALG to rely on it; and unlike in-kernel crypto API users, AF_ALG
 previously didn't have this problem.  So these "incompletely keyed"
 states became theoretically accessible via AF_ALG -- though, the
 opportunities for causing real mischief seem pretty limited.]

Fixes: 9fa68f620041 ("crypto: hash - prevent using keyed hashes without setting key")
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
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<pre>
commit ba7d7433a0e998c902132bd47330e355a1eaa894 upstream.

Some algorithms have a -&gt;setkey() method that is not atomic, in the
sense that setting a key can fail after changes were already made to the
tfm context.  In this case, if a key was already set the tfm can end up
in a state that corresponds to neither the old key nor the new key.

It's not feasible to make all -&gt;setkey() methods atomic, especially ones
that have to key multiple sub-tfms.  Therefore, make the crypto API set
CRYPTO_TFM_NEED_KEY if -&gt;setkey() fails and the algorithm requires a
key, to prevent the tfm from being used until a new key is set.

Note: we can't set CRYPTO_TFM_NEED_KEY for OPTIONAL_KEY algorithms, so
-&gt;setkey() for those must nevertheless be atomic.  That's fine for now
since only the crc32 and crc32c algorithms set OPTIONAL_KEY, and it's
not intended that OPTIONAL_KEY be used much.

[Cc stable mainly because when introducing the NEED_KEY flag I changed
 AF_ALG to rely on it; and unlike in-kernel crypto API users, AF_ALG
 previously didn't have this problem.  So these "incompletely keyed"
 states became theoretically accessible via AF_ALG -- though, the
 opportunities for causing real mischief seem pretty limited.]

Fixes: 9fa68f620041 ("crypto: hash - prevent using keyed hashes without setting key")
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
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