linux-stable.git/crypto/pcrypt.c, branch v4.14.331

crypto: pcrypt - Fix hungtask for PADATA_RESET

2023-11-28T16:45:43+00:00

[ Upstream commit 8f4f68e788c3a7a696546291258bfa5fdb215523 ]

We found a hungtask bug in test_aead_vec_cfg as follows:

INFO: task cryptomgr_test:391009 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Call trace:
 __switch_to+0x98/0xe0
 __schedule+0x6c4/0xf40
 schedule+0xd8/0x1b4
 schedule_timeout+0x474/0x560
 wait_for_common+0x368/0x4e0
 wait_for_completion+0x20/0x30
 wait_for_completion+0x20/0x30
 test_aead_vec_cfg+0xab4/0xd50
 test_aead+0x144/0x1f0
 alg_test_aead+0xd8/0x1e0
 alg_test+0x634/0x890
 cryptomgr_test+0x40/0x70
 kthread+0x1e0/0x220
 ret_from_fork+0x10/0x18
 Kernel panic - not syncing: hung_task: blocked tasks

For padata_do_parallel, when the return err is 0 or -EBUSY, it will call
wait_for_completion(&wait->completion) in test_aead_vec_cfg. In normal
case, aead_request_complete() will be called in pcrypt_aead_serial and the
return err is 0 for padata_do_parallel. But, when pinst->flags is
PADATA_RESET, the return err is -EBUSY for padata_do_parallel, and it
won't call aead_request_complete(). Therefore, test_aead_vec_cfg will
hung at wait_for_completion(&wait->completion), which will cause
hungtask.

The problem comes as following:
(padata_do_parallel)                 |
    rcu_read_lock_bh();              |
    err = -EINVAL;                   |   (padata_replace)
                                     |     pinst->flags |= PADATA_RESET;
    err = -EBUSY                     |
    if (pinst->flags & PADATA_RESET) |
        rcu_read_unlock_bh()         |
        return err

In order to resolve the problem, we replace the return err -EBUSY with
-EAGAIN, which means parallel_data is changing, and the caller should call
it again.

v3:
remove retry and just change the return err.
v2:
introduce padata_try_do_parallel() in pcrypt_aead_encrypt and
pcrypt_aead_decrypt to solve the hungtask.

Signed-off-by: Lu Jialin 
Signed-off-by: Guo Zihua 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

crypto: pcrypt - Delay write to padata->info

2021-11-26T10:40:32+00:00

[ Upstream commit 68b6dea802cea0dbdd8bd7ccc60716b5a32a5d8a ]

These three events can race when pcrypt is used multiple times in a
template ("pcrypt(pcrypt(...))"):

  1.  [taskA] The caller makes the crypto request via crypto_aead_encrypt()
  2.  [kworkerB] padata serializes the inner pcrypt request
  3.  [kworkerC] padata serializes the outer pcrypt request

3 might finish before the call to crypto_aead_encrypt() returns in 1,
resulting in two possible issues.

First, a use-after-free of the crypto request's memory when, for
example, taskA writes to the outer pcrypt request's padata->info in
pcrypt_aead_enc() after kworkerC completes the request.

Second, the outer pcrypt request overwrites the inner pcrypt request's
return code with -EINPROGRESS, making a successful request appear to
fail.  For instance, kworkerB writes the outer pcrypt request's
padata->info in pcrypt_aead_done() and then taskA overwrites it
in pcrypt_aead_enc().

Avoid both situations by delaying the write of padata->info until after
the inner crypto request's return code is checked.  This prevents the
use-after-free by not touching the crypto request's memory after the
next-inner crypto request is made, and stops padata->info from being
overwritten.

Fixes: 5068c7a883d16 ("crypto: pcrypt - Add pcrypt crypto parallelization wrapper")
Reported-by: syzbot+b187b77c8474f9648fae@syzkaller.appspotmail.com
Signed-off-by: Daniel Jordan 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

crypto: pcrypt - Do not clear MAY_SLEEP flag in original request

2020-02-14T21:32:14+00:00

commit e8d998264bffade3cfe0536559f712ab9058d654 upstream.

We should not be modifying the original request's MAY_SLEEP flag
upon completion.  It makes no sense to do so anyway.

Reported-by: Eric Biggers 
Fixes: 5068c7a883d1 ("crypto: pcrypt - Add pcrypt crypto...")
Signed-off-by: Herbert Xu 
Tested-by: Eric Biggers 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: pcrypt - Fix user-after-free on module unload

2020-02-05T14:18:11+00:00

[ Upstream commit 07bfd9bdf568a38d9440c607b72342036011f727 ]

On module unload of pcrypt we must unregister the crypto algorithms
first and then tear down the padata structure.  As otherwise the
crypto algorithms are still alive and can be used while the padata
structure is being freed.

Fixes: 5068c7a883d1 ("crypto: pcrypt - Add pcrypt crypto...")
Cc: 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

pcrypt: use format specifier in kobject_add

2020-01-27T13:46:06+00:00

[ Upstream commit b1e3874c75ab15288f573b3532e507c37e8e7656 ]

Passing string 'name' as the format specifier is potentially hazardous
because name could (although very unlikely to) have a format specifier
embedded in it causing issues when parsing the non-existent arguments
to these.  Follow best practice by using the "%s" format string for
the string 'name'.

Cleans up clang warning:
crypto/pcrypt.c:397:40: warning: format string is not a string literal
(potentially insecure) [-Wformat-security]

Fixes: a3fb1e330dd2 ("pcrypt: Added sysfs interface to pcrypt")
Signed-off-by: Colin Ian King 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

crypto: pcrypt - fix freeing pcrypt instances

2018-01-10T08:31:18+00:00

commit d76c68109f37cb85b243a1cf0f40313afd2bae68 upstream.

pcrypt is using the old way of freeing instances, where the ->free()
method specified in the 'struct crypto_template' is passed a pointer to
the 'struct crypto_instance'.  But the crypto_instance is being
kfree()'d directly, which is incorrect because the memory was actually
allocated as an aead_instance, which contains the crypto_instance at a
nonzero offset.  Thus, the wrong pointer was being kfree()'d.

Fix it by switching to the new way to free aead_instance's where the
->free() method is specified in the aead_instance itself.

Reported-by: syzbot 
Fixes: 0496f56065e0 ("crypto: pcrypt - Add support for new AEAD interface")
Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: aead - Remove CRYPTO_ALG_AEAD_NEW flag

2015-08-17T08:53:53+00:00

This patch removes the CRYPTO_ALG_AEAD_NEW flag now that everyone
has been converted.

Signed-off-by: Herbert Xu

crypto: pcrypt - Propagate new AEAD implementation flag

2015-07-14T06:56:45+00:00

This patch allows the CRYPTO_ALG_AEAD_NEW flag to be propagated.

It also restores the ASYNC bit that went missing during the AEAD
conversion.

Signed-off-by: Herbert Xu

crypto: pcrypt - Add support for new AEAD interface

2015-06-03T02:48:35+00:00

This patch converts pcrypt over to the new AEAD interface.

Signed-off-by: Herbert Xu

crypto: pcrypt - Make tfm_count an atomic_t

2015-05-25T10:41:25+00:00

The variable tfm_count is accessed by multiple threads without
locking.  This patch converts it to an atomic_t.

Signed-off-by: Herbert Xu