linux.git/crypto/internal.h, branch v5.1 Linux kernel source tree crypto: api - Introduce notifier for new crypto algorithms 2018-09-04T03:37:04+00:00 Martin K. Petersen martin.petersen@oracle.com 2018-08-30T15:00:14+00:00 dd8b083f9a5ed06946d559e0ca1eda0577ef24a9 Introduce a facility that can be used to receive a notification callback when a new algorithm becomes available. This can be used by existing crypto registrations to trigger a switch from a software-only algorithm to a hardware-accelerated version. A new CRYPTO_MSG_ALG_LOADED state is introduced to the existing crypto notification chain, and the register/unregister functions are exported so they can be called by subsystems outside of crypto. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Suggested-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 
Introduce a facility that can be used to receive a notification
callback when a new algorithm becomes available. This can be used by
existing crypto registrations to trigger a switch from a software-only
algorithm to a hardware-accelerated version.

A new CRYPTO_MSG_ALG_LOADED state is introduced to the existing crypto
notification chain, and the register/unregister functions are exported
so they can be called by subsystems outside of crypto.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Suggested-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto: api - Make crypto_alg_lookup static 2018-03-30T17:32:58+00:00 Herbert Xu herbert@gondor.apana.org.au 2018-03-20T00:05:39+00:00 3ca1e9948940230bd2c4b17e320bbab3367fc37b The function crypto_alg_lookup is only usd within the crypto API and should be not be exported to the modules. This patch marks it as a static function. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 
The function crypto_alg_lookup is only usd within the crypto API
and should be not be exported to the modules.  This patch marks
it as a static function.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto: algapi - remove unused notifications 2018-01-05T07:43:10+00:00 Eric Biggers ebiggers@google.com 2017-12-29T16:06:46+00:00 8b55107c57f763c7ca393e72f7ce6f89ea1ba49a There is a message posted to the crypto notifier chain when an algorithm is unregistered, and when a template is registered or unregistered. But nothing is listening for those messages; currently there are only listeners for the algorithm request and registration messages. Get rid of these unused notifications for now. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 
There is a message posted to the crypto notifier chain when an algorithm
is unregistered, and when a template is registered or unregistered.  But
nothing is listening for those messages; currently there are only
listeners for the algorithm request and registration messages.

Get rid of these unused notifications for now.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto: algapi - convert cra_refcnt to refcount_t 2018-01-05T07:43:09+00:00 Eric Biggers ebiggers@google.com 2017-12-29T16:00:46+00:00 ce8614a312ef750bb60677bb13680cb27d1c284b Reference counters should use refcount_t rather than atomic_t, since the refcount_t implementation can prevent overflows, reducing the exploitability of reference leak bugs. crypto_alg.cra_refcount is a reference counter with the usual semantics, so switch it over to refcount_t. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 
Reference counters should use refcount_t rather than atomic_t, since the
refcount_t implementation can prevent overflows, reducing the
exploitability of reference leak bugs.  crypto_alg.cra_refcount is a
reference counter with the usual semantics, so switch it over to
refcount_t.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto: api - Unexport crypto_larval_lookup() 2017-12-22T08:29:06+00:00 Eric Biggers ebiggers@google.com 2017-12-07T18:55:59+00:00 cadc9ab50350a24140612814109e826bb0e2ae37 crypto_larval_lookup() is not used outside of crypto/api.c, so unexport it and mark it 'static'. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 
crypto_larval_lookup() is not used outside of crypto/api.c, so unexport
it and mark it 'static'.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto: api - Remove no-op exit_ops code 2016-10-21T03:03:42+00:00 Eric Biggers ebiggers@google.com 2016-10-07T21:13:35+00:00 9c8ae17bbf416d837b81be7820d6d210d8353262 crypto_exit_cipher_ops() and crypto_exit_compress_ops() are no-ops and have been for a long time, so remove them. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 
crypto_exit_cipher_ops() and crypto_exit_compress_ops() are no-ops and
have been for a long time, so remove them.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto: api - Add crypto_type_has_alg helper 2016-01-25T14:42:12+00:00 Herbert Xu herbert@gondor.apana.org.au 2016-01-23T05:51:01+00:00 f2aefdab5dff83d3c801449051be1ba72c7e933a This patch adds the helper crypto_type_has_alg which is meant to replace crypto_has_alg for new-style crypto types. Rather than hard-coding type/mask information they're now retrieved from the crypto_type object. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 
This patch adds the helper crypto_type_has_alg which is meant
to replace crypto_has_alg for new-style crypto types.  Rather
than hard-coding type/mask information they're now retrieved
from the crypto_type object.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto: api - Remove linux/fips.h from internal.h 2015-04-23T06:18:10+00:00 Herbert Xu herbert@gondor.apana.org.au 2015-04-22T05:25:59+00:00 7be58b1250f471a4548c0fe7a6b4001b62ea1e30 Now that all fips_enabled users are including linux/fips.h directly instead of getting it through internal.h, we can remove the fips.h inclusions from internal.h. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 
Now that all fips_enabled users are including linux/fips.h directly
instead of getting it through internal.h, we can remove the fips.h
inclusions from internal.h.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto: api - Add crypto_alg_extsize helper 2015-04-21T02:19:54+00:00 Herbert Xu herbert@gondor.apana.org.au 2015-04-20T05:39:00+00:00 38d21433112c25acdb8e93f60be629e7a1c27a26 This patch adds a crypto_alg_extsize helper that can be used by algorithm types such as pcompress and shash. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 
This patch adds a crypto_alg_extsize helper that can be used
by algorithm types such as pcompress and shash.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto: algboss - Hold ref count on larval 2013-06-25T11:15:17+00:00 Herbert Xu herbert@gondor.apana.org.au 2013-06-25T11:15:17+00:00 939e17799619e31331d2433041196529515a86a6 On Thu, Jun 20, 2013 at 10:00:21AM +0200, Daniel Borkmann wrote: > After having fixed a NULL pointer dereference in SCTP 1abd165e ("net: > sctp: fix NULL pointer dereference in socket destruction"), I ran into > the following NULL pointer dereference in the crypto subsystem with > the same reproducer, easily hit each time: > > BUG: unable to handle kernel NULL pointer dereference at (null) > IP: [<ffffffff81070321>] __wake_up_common+0x31/0x90 > PGD 0 > Oops: 0000 [#1] SMP > Modules linked in: padlock_sha(F-) sha256_generic(F) sctp(F) libcrc32c(F) [..] > CPU: 6 PID: 3326 Comm: cryptomgr_probe Tainted: GF 3.10.0-rc5+ #1 > Hardware name: Dell Inc. PowerEdge T410/0H19HD, BIOS 1.6.3 02/01/2011 > task: ffff88007b6cf4e0 ti: ffff88007b7cc000 task.ti: ffff88007b7cc000 > RIP: 0010:[<ffffffff81070321>] [<ffffffff81070321>] __wake_up_common+0x31/0x90 > RSP: 0018:ffff88007b7cde08 EFLAGS: 00010082 > RAX: ffffffffffffffe8 RBX: ffff88003756c130 RCX: 0000000000000000 > RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff88003756c130 > RBP: ffff88007b7cde48 R08: 0000000000000000 R09: ffff88012b173200 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000282 > R13: ffff88003756c138 R14: 0000000000000000 R15: 0000000000000000 > FS: 0000000000000000(0000) GS:ffff88012fc60000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > CR2: 0000000000000000 CR3: 0000000001a0b000 CR4: 00000000000007e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Stack: > ffff88007b7cde28 0000000300000000 ffff88007b7cde28 ffff88003756c130 > 0000000000000282 ffff88003756c128 ffffffff81227670 0000000000000000 > ffff88007b7cde78 ffffffff810722b7 ffff88007cdcf000 ffffffff81a90540 > Call Trace: > [<ffffffff81227670>] ? crypto_alloc_pcomp+0x20/0x20 > [<ffffffff810722b7>] complete_all+0x47/0x60 > [<ffffffff81227708>] cryptomgr_probe+0x98/0xc0 > [<ffffffff81227670>] ? crypto_alloc_pcomp+0x20/0x20 > [<ffffffff8106760e>] kthread+0xce/0xe0 > [<ffffffff81067540>] ? kthread_freezable_should_stop+0x70/0x70 > [<ffffffff815450dc>] ret_from_fork+0x7c/0xb0 > [<ffffffff81067540>] ? kthread_freezable_should_stop+0x70/0x70 > Code: 41 56 41 55 41 54 53 48 83 ec 18 66 66 66 66 90 89 75 cc 89 55 c8 > 4c 8d 6f 08 48 8b 57 08 41 89 cf 4d 89 c6 48 8d 42 e > RIP [<ffffffff81070321>] __wake_up_common+0x31/0x90 > RSP <ffff88007b7cde08> > CR2: 0000000000000000 > ---[ end trace b495b19270a4d37e ]--- > > My assumption is that the following is happening: the minimal SCTP > tool runs under ``echo 1 > /proc/sys/net/sctp/auth_enable'', hence > it's making use of crypto_alloc_hash() via sctp_auth_init_hmacs(). > It forks itself, heavily allocates, binds, listens and waits in > accept on sctp sockets, and then randomly kills some of them (no > need for an actual client in this case to hit this). Then, again, > allocating, binding, etc, and then killing child processes. > > The problem that might be happening here is that cryptomgr requests > the module to probe/load through cryptomgr_schedule_probe(), but > before the thread handler cryptomgr_probe() returns, we return from > the wait_for_completion_interruptible() function and probably already > have cleared up larval, thus we run into a NULL pointer dereference > when in cryptomgr_probe() complete_all() is being called. > > If we wait with wait_for_completion() instead, this panic will not > occur anymore. This is valid, because in case a signal is pending, > cryptomgr_probe() returns from probing anyway with properly calling > complete_all(). The use of wait_for_completion_interruptible is intentional so that we don't lock up the thread if a bug causes us to never wake up. This bug is caused by the helper thread using the larval without holding a reference count on it. If the helper thread completes after the original thread requesting for help has gone away and destroyed the larval, then we get the crash above. So the fix is to hold a reference count on the larval. Cc: <stable@vger.kernel.org> # 3.6+ Reported-by: Daniel Borkmann <dborkman@redhat.com> Tested-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 
On Thu, Jun 20, 2013 at 10:00:21AM +0200, Daniel Borkmann wrote:
> After having fixed a NULL pointer dereference in SCTP 1abd165e ("net:
> sctp: fix NULL pointer dereference in socket destruction"), I ran into
> the following NULL pointer dereference in the crypto subsystem with
> the same reproducer, easily hit each time:
> 
> BUG: unable to handle kernel NULL pointer dereference at (null)
> IP: [<ffffffff81070321>] __wake_up_common+0x31/0x90
> PGD 0
> Oops: 0000 [#1] SMP
> Modules linked in: padlock_sha(F-) sha256_generic(F) sctp(F) libcrc32c(F) [..]
> CPU: 6 PID: 3326 Comm: cryptomgr_probe Tainted: GF            3.10.0-rc5+ #1
> Hardware name: Dell Inc. PowerEdge T410/0H19HD, BIOS 1.6.3 02/01/2011
> task: ffff88007b6cf4e0 ti: ffff88007b7cc000 task.ti: ffff88007b7cc000
> RIP: 0010:[<ffffffff81070321>]  [<ffffffff81070321>] __wake_up_common+0x31/0x90
> RSP: 0018:ffff88007b7cde08  EFLAGS: 00010082
> RAX: ffffffffffffffe8 RBX: ffff88003756c130 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff88003756c130
> RBP: ffff88007b7cde48 R08: 0000000000000000 R09: ffff88012b173200
> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000282
> R13: ffff88003756c138 R14: 0000000000000000 R15: 0000000000000000
> FS:  0000000000000000(0000) GS:ffff88012fc60000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> CR2: 0000000000000000 CR3: 0000000001a0b000 CR4: 00000000000007e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Stack:
>  ffff88007b7cde28 0000000300000000 ffff88007b7cde28 ffff88003756c130
>  0000000000000282 ffff88003756c128 ffffffff81227670 0000000000000000
>  ffff88007b7cde78 ffffffff810722b7 ffff88007cdcf000 ffffffff81a90540
> Call Trace:
>  [<ffffffff81227670>] ? crypto_alloc_pcomp+0x20/0x20
>  [<ffffffff810722b7>] complete_all+0x47/0x60
>  [<ffffffff81227708>] cryptomgr_probe+0x98/0xc0
>  [<ffffffff81227670>] ? crypto_alloc_pcomp+0x20/0x20
>  [<ffffffff8106760e>] kthread+0xce/0xe0
>  [<ffffffff81067540>] ? kthread_freezable_should_stop+0x70/0x70
>  [<ffffffff815450dc>] ret_from_fork+0x7c/0xb0
>  [<ffffffff81067540>] ? kthread_freezable_should_stop+0x70/0x70
> Code: 41 56 41 55 41 54 53 48 83 ec 18 66 66 66 66 90 89 75 cc 89 55 c8
>       4c 8d 6f 08 48 8b 57 08 41 89 cf 4d 89 c6 48 8d 42 e
> RIP  [<ffffffff81070321>] __wake_up_common+0x31/0x90
>  RSP <ffff88007b7cde08>
> CR2: 0000000000000000
> ---[ end trace b495b19270a4d37e ]---
> 
> My assumption is that the following is happening: the minimal SCTP
> tool runs under ``echo 1 > /proc/sys/net/sctp/auth_enable'', hence
> it's making use of crypto_alloc_hash() via sctp_auth_init_hmacs().
> It forks itself, heavily allocates, binds, listens and waits in
> accept on sctp sockets, and then randomly kills some of them (no
> need for an actual client in this case to hit this). Then, again,
> allocating, binding, etc, and then killing child processes.
> 
> The problem that might be happening here is that cryptomgr requests
> the module to probe/load through cryptomgr_schedule_probe(), but
> before the thread handler cryptomgr_probe() returns, we return from
> the wait_for_completion_interruptible() function and probably already
> have cleared up larval, thus we run into a NULL pointer dereference
> when in cryptomgr_probe() complete_all() is being called.
> 
> If we wait with wait_for_completion() instead, this panic will not
> occur anymore. This is valid, because in case a signal is pending,
> cryptomgr_probe() returns from probing anyway with properly calling
> complete_all().

The use of wait_for_completion_interruptible is intentional so that
we don't lock up the thread if a bug causes us to never wake up.

This bug is caused by the helper thread using the larval without
holding a reference count on it.  If the helper thread completes
after the original thread requesting for help has gone away and
destroyed the larval, then we get the crash above.

So the fix is to hold a reference count on the larval.

Cc: <stable@vger.kernel.org> # 3.6+
Reported-by: Daniel Borkmann <dborkman@redhat.com>
Tested-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>