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>
It has been observed that sometimes the crypto allocation code
will get stuck for 60 seconds or multiples thereof. This is
usually caused by an algorithm failing to pass the self-test.
If an algorithm fails to be constructed, we will immediately notify
all larval waiters. However, if it succeeds in construction, but
then fails the self-test, we won't notify anyone at all.
This patch fixes this by merging the notification in the case
where the algorithm fails to be constructed with that of the
the case where it pases the self-test. This way regardless of
what happens, we'll give the larval waiters an answer.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The upcomming crypto usrerspace configuration api needs
to remove the spawns on top on an algorithm, so export
crypto_remove_final.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The upcomming crypto usrerspace configuration api needs
to remove the spawns on top on an algorithm, so export
crypto_remove_spawns.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch changes cryptd to use the template->create function
instead of alloc in anticipation for the switch to new style
ahash algorithms.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch removes the implementation of hash and digest now that
no algorithms use them anymore. The interface though will remain
until the users are converted across.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds the helper crypto_attr_alg2 which is similar to
crypto_attr_alg but takes an extra frontend argument. This is
intended to be used by new style algorithm types such as shash.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
FIPS-140 requires that all random number generators implement continuous self
tests in which each extracted block of data is compared against the last block
for repetition. The ansi_cprng implements such a test, but it would be nice if
the hw rng's did the same thing. Obviously its not something thats always
needed, but it seems like it would be a nice feature to have on occasion. I've
written the below patch which allows individual entropy stores to be flagged as
desiring a continuous test to be run on them as is extracted. By default this
option is off, but is enabled in the event that fips mode is selected during
bootup.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
We currently allocate temporary memory that is used for testing
statically. This renders the testing engine non-reentrant. As
algorithms may nest, i.e., one may construct another in order to
carry out a part of its operation, this is unacceptable. For
example, it has been reported that an AEAD implementation allocates
a cipher in its setkey function, which causes it to fail during
testing as the temporary memory is overwritten.
This patch replaces the static memory with dynamically allocated
buffers. We need a maximum of 16 pages so this slightly increases
the chances of an algorithm failing due to memory shortage.
However, as testing usually occurs at registration, this shouldn't
be a big problem.
Reported-by: Shasi Pulijala <spulijala@amcc.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This is based on a report and patch by Geert Uytterhoeven.
The functions crypto_alloc_tfm and create_create_tfm return a
pointer that needs to be adjusted by the caller when successful
and otherwise an error value. This means that the caller has
to check for the error and only perform the adjustment if the
pointer returned is valid.
Since all callers want to make the adjustment and we know how
to adjust it ourselves, it's much easier to just return adjusted
pointer directly.
The only caveat is that we have to return a void * instead of
struct crypto_tfm *. However, this isn't that bad because both
of these functions are for internal use only (by types code like
shash.c, not even algorithms code).
This patch also moves crypto_alloc_tfm into crypto/internal.h
(crypto_create_tfm is already there) to reflect this.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch reintroduces a completely revamped crypto_alloc_tfm.
The biggest change is that we now take two crypto_type objects
when allocating a tfm, a frontend and a backend. In fact this
simply formalises what we've been doing behind the API's back.
For example, as it stands crypto_alloc_ahash may use an
actual ahash algorithm or a crypto_hash algorithm. Putting
this in the API allows us to do this much more cleanly.
The existing types will be converted across gradually.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add the ability to turn FIPS-compliant mode on or off at boot
In order to be FIPS compliant, several check may need to be preformed that may
be construed as unusefull in a non-compliant mode. This patch allows us to set
a kernel flag incating that we are running in a fips-compliant mode from boot
up. It also exports that mode information to user space via a sysctl
(/proc/sys/crypto/fips_enabled).
Tested successfully by me.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch makes use of the new testing infrastructure by requiring
algorithms to pass a run-time test before they're made available to
users.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch moves the newly created alg_test infrastructure into
cryptomgr. This shall allow us to use it for testing at algorithm
registrations.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since the only user of __crypto_alg_lookup is doing exactly what
crypto_alg_lookup does, we can now the latter in lieu of the former.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch makes crypto_alloc_ablkcipher/crypto_grab_skcipher always
return algorithms that are capable of generating their own IVs through
givencrypt and givdecrypt. Each algorithm may specify its default IV
generator through the geniv field.
For algorithms that do not set the geniv field, the blkcipher layer will
pick a default. Currently it's chainiv for synchronous algorithms and
eseqiv for asynchronous algorithms. Note that if these wrappers do not
work on an algorithm then that algorithm must specify its own geniv or
it can't be used at all.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The scatterwalk infrastructure is used by algorithms so it needs to
move out of crypto for future users that may live in drivers/crypto
or asm/*/crypto.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When scatterwalk is built as a module digest.c was broken because it
requires the crypto_km_types structure which is in scatterwalk. This
patch removes the crypto_km_types structure by encoding the logic into
crypto_kmap_type directly.
In fact, this even saves a few bytes of code (not to mention the data
structure itself) on i386 which is about the only place where it's
needed.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds support for multiple frontend types for each backend
algorithm by passing the type and mask through to the backend type
init function.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch removes the old HMAC implementation now that nobody uses it
anymore.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds two block cipher algorithms, CBC and ECB. These
are implemented as templates on top of existing single-block cipher
algorithms. They invoke the single-block cipher through the new
encrypt_one/decrypt_one interface.
This also optimises the in-place encryption and decryption to remove
the cost of an IV copy each round.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The sleeping flag used to determine whether crypto_yield can actually
yield is really a per-operation flag rather than a per-tfm flag. This
patch changes crypto_yield to take a flag directly so that we can start
using a per-operation flag instead the tfm flag.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When the final result location is unaligned, we store the digest in a
temporary buffer before copying it to the final location. Currently
that buffer sits on the stack. This patch moves it to an area in the
tfm, just like the CBC IV buffer.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Spawns lock a specific crypto algorithm in place. They can then be used
with crypto_spawn_tfm to allocate a tfm for that algorithm. When the base
algorithm of a spawn is deregistered, all its spawns will be automatically
removed.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch also adds the infrastructure to pick an algorithm based on
their type. For example, this allows you to select the encryption
algorithm "aes", instead of any algorithm registered under the name
"aes". For now this is only accessible internally. Eventually it
will be made available through crypto_alloc_tfm.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds a notifier chain for algorithm/template registration events.
This will be used to register compound algorithms such as cbc(aes). In
future this will also be passed onto user-space through netlink.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
A crypto_template generates a crypto_alg object when given a set of
parameters. this patch adds the basic data structure fo templates
and code to handle their registration/deregistration.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The crypto API is made up of the part facing users such as IPsec and the
low-level part which is used by cryptographic entities such as algorithms.
This patch splits out the latter so that the two APIs are more clearly
delineated. As a bonus the low-level API can now be modularised if all
algorithms are built as modules.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This is the first step on the road towards asynchronous support in
the Crypto API. It adds support for having multiple crypto_alg objects
for the same algorithm registered in the system.
For example, each device driver would register a crypto_alg object
for each algorithm that it supports. While at the same time the
user may load software implementations of those same algorithms.
Users of the Crypto API may then select a specific implementation
by name, or choose any implementation for a given algorithm with
the highest priority.
The priority field is a 32-bit signed integer. In future it will be
possible to modify it from user-space.
This also provides a solution to the problem of selecting amongst
various AES implementations, that is, aes vs. aes-i586 vs. aes-padlock.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The crypto layer currently uses in_atomic() to determine whether it is
allowed to sleep. This is incorrect since spin locks don't always cause
in_atomic() to return true.
Instead of that, this patch returns to an earlier idea of a per-tfm flag
which determines whether sleeping is allowed. Unlike the earlier version,
the default is to not allow sleeping. This ensures that no existing code
can break.
As usual, this flag may either be set through crypto_alloc_tfm(), or
just before a specific crypto operation.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch ensures that cit_iv is aligned according to cra_alignmask
by allocating it as part of the tfm structure. As a side effect the
crypto layer will also guarantee that the tfm ctx area has enough space
to be aligned by cra_alignmask. This allows us to remove the extra
space reservation from the Padlock driver.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch makes a needlessly global function static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds hooks for cipher algorithms to implement multi-block
ECB/CBC operations directly. This is expected to provide significant
performance boots to the VIA Padlock.
It could also be used for improving software implementations such as
AES where operating on multiple blocks at a time may enable certain
optimisations.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The netlink gfp_any() problem made me double-check the uses of in_softirq()
in crypto/*. It seems to me that we should be checking in_atomic() instead
of in_softirq() in crypto_yield. Otherwise people calling the crypto ops
with spin locks held or preemption disabled will get burnt, right?
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
