<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include/crypto, branch v4.15.6</title>
<subtitle>Linux Kernel
</subtitle>
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<updated>2018-02-16T19:06:48Z</updated>
<entry>
<title>crypto: hash - prevent using keyed hashes without setting key</title>
<updated>2018-02-16T19:06:48Z</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2018-01-03T19:16:27Z</published>
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<id>urn:sha1:46e8d06e423c4f35eac7a8b677b713b3ec9b0684</id>
<content type='text'>
commit 9fa68f620041be04720d0cbfb1bd3ddfc6310b24 upstream.

Currently, almost none of the keyed hash algorithms check whether a key
has been set before proceeding.  Some algorithms are okay with this and
will effectively just use a key of all 0's or some other bogus default.
However, others will severely break, as demonstrated using
"hmac(sha3-512-generic)", the unkeyed use of which causes a kernel crash
via a (potentially exploitable) stack buffer overflow.

A while ago, this problem was solved for AF_ALG by pairing each hash
transform with a 'has_key' bool.  However, there are still other places
in the kernel where userspace can specify an arbitrary hash algorithm by
name, and the kernel uses it as unkeyed hash without checking whether it
is really unkeyed.  Examples of this include:

    - KEYCTL_DH_COMPUTE, via the KDF extension
    - dm-verity
    - dm-crypt, via the ESSIV support
    - dm-integrity, via the "internal hash" mode with no key given
    - drbd (Distributed Replicated Block Device)

This bug is especially bad for KEYCTL_DH_COMPUTE as that requires no
privileges to call.

Fix the bug for all users by adding a flag CRYPTO_TFM_NEED_KEY to the
-&gt;crt_flags of each hash transform that indicates whether the transform
still needs to be keyed or not.  Then, make the hash init, import, and
digest functions return -ENOKEY if the key is still needed.

The new flag also replaces the 'has_key' bool which algif_hash was
previously using, thereby simplifying the algif_hash implementation.

Reported-by: syzbot &lt;syzkaller@googlegroups.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: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>crypto: poly1305 - remove -&gt;setkey() method</title>
<updated>2018-02-16T19:06:48Z</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2018-01-03T19:16:25Z</published>
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<id>urn:sha1:b5e994037f37e9e8b8ecfc43d6ef8a93f52633e5</id>
<content type='text'>
commit a16e772e664b9a261424107784804cffc8894977 upstream.

Since Poly1305 requires a nonce per invocation, the Linux kernel
implementations of Poly1305 don't use the crypto API's keying mechanism
and instead expect the key and nonce as the first 32 bytes of the data.
But -&gt;setkey() is still defined as a stub returning an error code.  This
prevents Poly1305 from being used through AF_ALG and will also break it
completely once we start enforcing that all crypto API users (not just
AF_ALG) call -&gt;setkey() if present.

Fix it by removing crypto_poly1305_setkey(), leaving -&gt;setkey as NULL.

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;

</content>
</entry>
<entry>
<title>crypto: hash - introduce crypto_hash_alg_has_setkey()</title>
<updated>2018-02-16T19:06:47Z</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2018-01-03T19:16:22Z</published>
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<id>urn:sha1:927a0dd1c4de3ec57e8d1194bd0383ca757162eb</id>
<content type='text'>
commit cd6ed77ad5d223dc6299fb58f62e0f5267f7e2ba upstream.

Templates that use an shash spawn can use crypto_shash_alg_has_setkey()
to determine whether the underlying algorithm requires a key or not.
But there was no corresponding function for ahash spawns.  Add it.

Note that the new function actually has to support both shash and ahash
algorithms, since the ahash API can be used with either.

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;

</content>
</entry>
<entry>
<title>Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6</title>
<updated>2018-01-05T20:10:06Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-01-05T20:10:06Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=64648a5fcabf46000a496c41c92c5c0f16be78ed'/>
<id>urn:sha1:64648a5fcabf46000a496c41c92c5c0f16be78ed</id>
<content type='text'>
Pull crypto fixes from Herbert Xu:
 "This fixes the following issues:

   - racy use of ctx-&gt;rcvused in af_alg

   - algif_aead crash in chacha20poly1305

   - freeing bogus pointer in pcrypt

   - build error on MIPS in mpi

   - memory leak in inside-secure

   - memory overwrite in inside-secure

   - NULL pointer dereference in inside-secure

   - state corruption in inside-secure

   - build error without CRYPTO_GF128MUL in chelsio

   - use after free in n2"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: inside-secure - do not use areq-&gt;result for partial results
  crypto: inside-secure - fix request allocations in invalidation path
  crypto: inside-secure - free requests even if their handling failed
  crypto: inside-secure - per request invalidation
  lib/mpi: Fix umul_ppmm() for MIPS64r6
  crypto: pcrypt - fix freeing pcrypt instances
  crypto: n2 - cure use after free
  crypto: af_alg - Fix race around ctx-&gt;rcvused by making it atomic_t
  crypto: chacha20poly1305 - validate the digest size
  crypto: chelsio - select CRYPTO_GF128MUL
</content>
</entry>
<entry>
<title>Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6</title>
<updated>2017-12-22T20:22:48Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-12-22T20:22:48Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=0fc0f18bed026a7aa6d5499d06cc9a6eb47dc3cc'/>
<id>urn:sha1:0fc0f18bed026a7aa6d5499d06cc9a6eb47dc3cc</id>
<content type='text'>
Pull crypto fixes from Herbert Xu:
 "This fixes the following issues:

   - fix chacha20 crash on zero-length input due to unset IV

   - fix potential race conditions in mcryptd with spinlock

   - only wait once at top of algif recvmsg to avoid inconsistencies

   - fix potential use-after-free in algif_aead/algif_skcipher"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: af_alg - fix race accessing cipher request
  crypto: mcryptd - protect the per-CPU queue with a lock
  crypto: af_alg - wait for data at beginning of recvmsg
  crypto: skcipher - set walk.iv for zero-length inputs
</content>
</entry>
<entry>
<title>crypto: af_alg - Fix race around ctx-&gt;rcvused by making it atomic_t</title>
<updated>2017-12-22T08:02:40Z</updated>
<author>
<name>Jonathan Cameron</name>
<email>Jonathan.Cameron@huawei.com</email>
</author>
<published>2017-12-19T10:27:24Z</published>
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<id>urn:sha1:af955bf15d2c27496b0269b1f05c26f758c68314</id>
<content type='text'>
This variable was increased and decreased without any protection.
Result was an occasional misscount and negative wrap around resulting
in false resource allocation failures.

Fixes: 7d2c3f54e6f6 ("crypto: af_alg - remove locking in async callback")
Signed-off-by: Jonathan Cameron &lt;Jonathan.Cameron@huawei.com&gt;
Reviewed-by: Stephan Mueller &lt;smueller@chronox.de&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
<entry>
<title>Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6</title>
<updated>2017-12-12T00:32:45Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-12-12T00:32:45Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=916b20e02e1579fcca139b04ccfe25d61594faa8'/>
<id>urn:sha1:916b20e02e1579fcca139b04ccfe25d61594faa8</id>
<content type='text'>
Pull crypto fixes from Herbert Xu:
 "This push fixes the following issues:

   - buffer overread in RSA

   - potential use after free in algif_aead.

   - error path null pointer dereference in af_alg

   - forbid combinations such as hmac(hmac(sha3)) which may crash

   - crash in salsa20 due to incorrect API usage"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: salsa20 - fix blkcipher_walk API usage
  crypto: hmac - require that the underlying hash algorithm is unkeyed
  crypto: af_alg - fix NULL pointer dereference in
  crypto: algif_aead - fix reference counting of null skcipher
  crypto: rsa - fix buffer overread when stripping leading zeroes
</content>
</entry>
<entry>
<title>crypto: mcryptd - protect the per-CPU queue with a lock</title>
<updated>2017-12-11T11:29:54Z</updated>
<author>
<name>Sebastian Andrzej Siewior</name>
<email>bigeasy@linutronix.de</email>
</author>
<published>2017-11-30T12:39:27Z</published>
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<id>urn:sha1:9abffc6f2efe46c3564c04312e52e07622d40e51</id>
<content type='text'>
mcryptd_enqueue_request() grabs the per-CPU queue struct and protects
access to it with disabled preemption. Then it schedules a worker on the
same CPU. The worker in mcryptd_queue_worker() guards access to the same
per-CPU variable with disabled preemption.

If we take CPU-hotplug into account then it is possible that between
queue_work_on() and the actual invocation of the worker the CPU goes
down and the worker will be scheduled on _another_ CPU. And here the
preempt_disable() protection does not work anymore. The easiest thing is
to add a spin_lock() to guard access to the list.

Another detail: mcryptd_queue_worker() is not processing more than
MCRYPTD_BATCH invocation in a row. If there are still items left, then
it will invoke queue_work() to proceed with more later. *I* would
suggest to simply drop that check because it does not use a system
workqueue and the workqueue is already marked as "CPU_INTENSIVE". And if
preemption is required then the scheduler should do it.
However if queue_work() is used then the work item is marked as CPU
unbound. That means it will try to run on the local CPU but it may run
on another CPU as well. Especially with CONFIG_DEBUG_WQ_FORCE_RR_CPU=y.
Again, the preempt_disable() won't work here but lock which was
introduced will help.
In order to keep work-item on the local CPU (and avoid RR) I changed it
to queue_work_on().

Cc: stable@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
<entry>
<title>crypto: hmac - require that the underlying hash algorithm is unkeyed</title>
<updated>2017-11-29T02:39:15Z</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2017-11-29T02:01:38Z</published>
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<id>urn:sha1:af3ff8045bbf3e32f1a448542e73abb4c8ceb6f1</id>
<content type='text'>
Because the HMAC template didn't check that its underlying hash
algorithm is unkeyed, trying to use "hmac(hmac(sha3-512-generic))"
through AF_ALG or through KEYCTL_DH_COMPUTE resulted in the inner HMAC
being used without having been keyed, resulting in sha3_update() being
called without sha3_init(), causing a stack buffer overflow.

This is a very old bug, but it seems to have only started causing real
problems when SHA-3 support was added (requires CONFIG_CRYPTO_SHA3)
because the innermost hash's state is -&gt;import()ed from a zeroed buffer,
and it just so happens that other hash algorithms are fine with that,
but SHA-3 is not.  However, there could be arch or hardware-dependent
hash algorithms also affected; I couldn't test everything.

Fix the bug by introducing a function crypto_shash_alg_has_setkey()
which tests whether a shash algorithm is keyed.  Then update the HMAC
template to require that its underlying hash algorithm is unkeyed.

Here is a reproducer:

    #include &lt;linux/if_alg.h&gt;
    #include &lt;sys/socket.h&gt;

    int main()
    {
        int algfd;
        struct sockaddr_alg addr = {
            .salg_type = "hash",
            .salg_name = "hmac(hmac(sha3-512-generic))",
        };
        char key[4096] = { 0 };

        algfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
        bind(algfd, (const struct sockaddr *)&amp;addr, sizeof(addr));
        setsockopt(algfd, SOL_ALG, ALG_SET_KEY, key, sizeof(key));
    }

Here was the KASAN report from syzbot:

    BUG: KASAN: stack-out-of-bounds in memcpy include/linux/string.h:341  [inline]
    BUG: KASAN: stack-out-of-bounds in sha3_update+0xdf/0x2e0  crypto/sha3_generic.c:161
    Write of size 4096 at addr ffff8801cca07c40 by task syzkaller076574/3044

    CPU: 1 PID: 3044 Comm: syzkaller076574 Not tainted 4.14.0-mm1+ #25
    Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  Google 01/01/2011
    Call Trace:
      __dump_stack lib/dump_stack.c:17 [inline]
      dump_stack+0x194/0x257 lib/dump_stack.c:53
      print_address_description+0x73/0x250 mm/kasan/report.c:252
      kasan_report_error mm/kasan/report.c:351 [inline]
      kasan_report+0x25b/0x340 mm/kasan/report.c:409
      check_memory_region_inline mm/kasan/kasan.c:260 [inline]
      check_memory_region+0x137/0x190 mm/kasan/kasan.c:267
      memcpy+0x37/0x50 mm/kasan/kasan.c:303
      memcpy include/linux/string.h:341 [inline]
      sha3_update+0xdf/0x2e0 crypto/sha3_generic.c:161
      crypto_shash_update+0xcb/0x220 crypto/shash.c:109
      shash_finup_unaligned+0x2a/0x60 crypto/shash.c:151
      crypto_shash_finup+0xc4/0x120 crypto/shash.c:165
      hmac_finup+0x182/0x330 crypto/hmac.c:152
      crypto_shash_finup+0xc4/0x120 crypto/shash.c:165
      shash_digest_unaligned+0x9e/0xd0 crypto/shash.c:172
      crypto_shash_digest+0xc4/0x120 crypto/shash.c:186
      hmac_setkey+0x36a/0x690 crypto/hmac.c:66
      crypto_shash_setkey+0xad/0x190 crypto/shash.c:64
      shash_async_setkey+0x47/0x60 crypto/shash.c:207
      crypto_ahash_setkey+0xaf/0x180 crypto/ahash.c:200
      hash_setkey+0x40/0x90 crypto/algif_hash.c:446
      alg_setkey crypto/af_alg.c:221 [inline]
      alg_setsockopt+0x2a1/0x350 crypto/af_alg.c:254
      SYSC_setsockopt net/socket.c:1851 [inline]
      SyS_setsockopt+0x189/0x360 net/socket.c:1830
      entry_SYSCALL_64_fastpath+0x1f/0x96

Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
<entry>
<title>Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6</title>
<updated>2017-11-29T00:22:10Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-11-29T00:22:10Z</published>
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<id>urn:sha1:43570f0383d6d5879ae585e6c3cf027ba321546f</id>
<content type='text'>
Pull crypto fixes from Herbert Xu:

 - avoid potential bogus alignment for some AEAD operations

 - fix crash in algif_aead

 - avoid sleeping in softirq context with async af_alg

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: skcipher - Fix skcipher_walk_aead_common
  crypto: af_alg - remove locking in async callback
  crypto: algif_aead - skip SGL entries with NULL page
</content>
</entry>
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