2015-09-18 15:32:19

by Thomas Petazzoni

[permalink] [raw]
Subject: [PATCH] crypto: marvell: properly handle CRYPTO_TFM_REQ_MAY_BACKLOG-flagged requests

The mv_cesa_queue_req() function calls crypto_enqueue_request() to
enqueue a request. In the normal case (i.e the queue isn't full), this
function returns -EINPROGRESS. The current Marvell CESA crypto driver
takes this into account and cleans up the request only if an error
occured, i.e if the return value is not -EINPROGRESS.

Unfortunately this causes problems with
CRYPTO_TFM_REQ_MAY_BACKLOG-flagged requests. When such a request is
passed to crypto_enqueue_request() and the queue is full,
crypto_enqueue_request() will return -EBUSY, but will keep the request
enqueued nonetheless. This situation was not properly handled by the
Marvell CESA driver, which was anyway cleaning up the request in such
a situation. When later on the request was taken out of the backlog
and actually processed, a kernel crash occured due to the internal
driver data structures for this structure having been cleaned up.

To avoid this situation, this commit adds a
mv_cesa_req_needs_cleanup() helper function which indicates if the
request needs to be cleaned up or not after a call to
crypto_enqueue_request(). This helper allows to do the cleanup only in
the appropriate cases, and all call sites of mv_cesa_queue_req() are
fixed to use this new helper function.

Reported-by: Vincent Donnefort <[email protected]>
Fixes: db509a45339fd ("crypto: marvell/cesa - add TDMA support")
Cc: <[email protected]> # v4.2+
Signed-off-by: Thomas Petazzoni <[email protected]>
---
drivers/crypto/marvell/cesa.h | 27 +++++++++++++++++++++++++++
drivers/crypto/marvell/cipher.c | 7 +++----
drivers/crypto/marvell/hash.c | 8 +++-----
3 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/drivers/crypto/marvell/cesa.h b/drivers/crypto/marvell/cesa.h
index b60698b..bc2a55b 100644
--- a/drivers/crypto/marvell/cesa.h
+++ b/drivers/crypto/marvell/cesa.h
@@ -687,6 +687,33 @@ static inline u32 mv_cesa_get_int_mask(struct mv_cesa_engine *engine)

int mv_cesa_queue_req(struct crypto_async_request *req);

+/*
+ * Helper function that indicates whether a crypto request needs to be
+ * cleaned up or not after being enqueued using mv_cesa_queue_req().
+ */
+static inline int mv_cesa_req_needs_cleanup(struct crypto_async_request *req,
+ int ret)
+{
+ /*
+ * The queue still had some space, the request was queued
+ * normally, so there's no need to clean it up.
+ */
+ if (ret == -EINPROGRESS)
+ return false;
+
+ /*
+ * The queue had not space left, but since the request is
+ * flagged with CRYPTO_TFM_REQ_MAY_BACKLOG, it was added to
+ * the backlog and will be processed later. There's no need to
+ * clean it up.
+ */
+ if (ret == -EBUSY && req->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)
+ return false;
+
+ /* Request wasn't queued, we need to clean it up */
+ return true;
+}
+
/* TDMA functions */

static inline void mv_cesa_req_dma_iter_init(struct mv_cesa_dma_iter *iter,
diff --git a/drivers/crypto/marvell/cipher.c b/drivers/crypto/marvell/cipher.c
index 0745cf3..3df2f4e 100644
--- a/drivers/crypto/marvell/cipher.c
+++ b/drivers/crypto/marvell/cipher.c
@@ -189,7 +189,6 @@ static inline void mv_cesa_ablkcipher_prepare(struct crypto_async_request *req,
{
struct ablkcipher_request *ablkreq = ablkcipher_request_cast(req);
struct mv_cesa_ablkcipher_req *creq = ablkcipher_request_ctx(ablkreq);
-
creq->req.base.engine = engine;

if (creq->req.base.type == CESA_DMA_REQ)
@@ -431,7 +430,7 @@ static int mv_cesa_des_op(struct ablkcipher_request *req,
return ret;

ret = mv_cesa_queue_req(&req->base);
- if (ret && ret != -EINPROGRESS)
+ if (mv_cesa_req_needs_cleanup(&req->base, ret))
mv_cesa_ablkcipher_cleanup(req);

return ret;
@@ -551,7 +550,7 @@ static int mv_cesa_des3_op(struct ablkcipher_request *req,
return ret;

ret = mv_cesa_queue_req(&req->base);
- if (ret && ret != -EINPROGRESS)
+ if (mv_cesa_req_needs_cleanup(&req->base, ret))
mv_cesa_ablkcipher_cleanup(req);

return ret;
@@ -693,7 +692,7 @@ static int mv_cesa_aes_op(struct ablkcipher_request *req,
return ret;

ret = mv_cesa_queue_req(&req->base);
- if (ret && ret != -EINPROGRESS)
+ if (mv_cesa_req_needs_cleanup(&req->base, ret))
mv_cesa_ablkcipher_cleanup(req);

return ret;
diff --git a/drivers/crypto/marvell/hash.c b/drivers/crypto/marvell/hash.c
index ae9272e..e8d0d71 100644
--- a/drivers/crypto/marvell/hash.c
+++ b/drivers/crypto/marvell/hash.c
@@ -739,10 +739,8 @@ static int mv_cesa_ahash_update(struct ahash_request *req)
return 0;

ret = mv_cesa_queue_req(&req->base);
- if (ret && ret != -EINPROGRESS) {
+ if (mv_cesa_req_needs_cleanup(&req->base, ret))
mv_cesa_ahash_cleanup(req);
- return ret;
- }

return ret;
}
@@ -766,7 +764,7 @@ static int mv_cesa_ahash_final(struct ahash_request *req)
return 0;

ret = mv_cesa_queue_req(&req->base);
- if (ret && ret != -EINPROGRESS)
+ if (mv_cesa_req_needs_cleanup(&req->base, ret))
mv_cesa_ahash_cleanup(req);

return ret;
@@ -791,7 +789,7 @@ static int mv_cesa_ahash_finup(struct ahash_request *req)
return 0;

ret = mv_cesa_queue_req(&req->base);
- if (ret && ret != -EINPROGRESS)
+ if (mv_cesa_req_needs_cleanup(&req->base, ret))
mv_cesa_ahash_cleanup(req);

return ret;
--
2.5.2


2015-09-18 15:43:25

by Boris Brezillon

[permalink] [raw]
Subject: Re: [PATCH] crypto: marvell: properly handle CRYPTO_TFM_REQ_MAY_BACKLOG-flagged requests

Hi Thomas,

On Fri, 18 Sep 2015 17:25:36 +0200
Thomas Petazzoni <[email protected]> wrote:

> The mv_cesa_queue_req() function calls crypto_enqueue_request() to
> enqueue a request. In the normal case (i.e the queue isn't full), this
> function returns -EINPROGRESS. The current Marvell CESA crypto driver
> takes this into account and cleans up the request only if an error
> occured, i.e if the return value is not -EINPROGRESS.
>
> Unfortunately this causes problems with
> CRYPTO_TFM_REQ_MAY_BACKLOG-flagged requests. When such a request is
> passed to crypto_enqueue_request() and the queue is full,
> crypto_enqueue_request() will return -EBUSY, but will keep the request
> enqueued nonetheless. This situation was not properly handled by the
> Marvell CESA driver, which was anyway cleaning up the request in such
> a situation. When later on the request was taken out of the backlog
> and actually processed, a kernel crash occured due to the internal
> driver data structures for this structure having been cleaned up.
>
> To avoid this situation, this commit adds a
> mv_cesa_req_needs_cleanup() helper function which indicates if the
> request needs to be cleaned up or not after a call to
> crypto_enqueue_request(). This helper allows to do the cleanup only in
> the appropriate cases, and all call sites of mv_cesa_queue_req() are
> fixed to use this new helper function.
>
> Reported-by: Vincent Donnefort <[email protected]>
> Fixes: db509a45339fd ("crypto: marvell/cesa - add TDMA support")
> Cc: <[email protected]> # v4.2+
> Signed-off-by: Thomas Petazzoni <[email protected]>

Acked-by: Boris Brezillon <[email protected]>

> ---
> drivers/crypto/marvell/cesa.h | 27 +++++++++++++++++++++++++++
> drivers/crypto/marvell/cipher.c | 7 +++----
> drivers/crypto/marvell/hash.c | 8 +++-----
> 3 files changed, 33 insertions(+), 9 deletions(-)
>

[...]

>
> static inline void mv_cesa_req_dma_iter_init(struct mv_cesa_dma_iter *iter,
> diff --git a/drivers/crypto/marvell/cipher.c b/drivers/crypto/marvell/cipher.c
> index 0745cf3..3df2f4e 100644
> --- a/drivers/crypto/marvell/cipher.c
> +++ b/drivers/crypto/marvell/cipher.c
> @@ -189,7 +189,6 @@ static inline void mv_cesa_ablkcipher_prepare(struct crypto_async_request *req,
> {
> struct ablkcipher_request *ablkreq = ablkcipher_request_cast(req);
> struct mv_cesa_ablkcipher_req *creq = ablkcipher_request_ctx(ablkreq);
> -

Nitpick, but you're removing an empty line, and this doesn't seem
related to the bug itself.

Anyway, Thanks for fixing that.

Best Regards,

Boris

--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

2015-09-21 09:15:38

by Vincent Donnefort

[permalink] [raw]
Subject: Re: [PATCH] crypto: marvell: properly handle CRYPTO_TFM_REQ_MAY_BACKLOG-flagged requests

Hi Thomas,

Your patch fixes the problem on my side.

Tested-by: Vincent Donnefort <[email protected]>

On Fri, Sep 18, 2015 at 05:25:36PM +0200, Thomas Petazzoni wrote:
> The mv_cesa_queue_req() function calls crypto_enqueue_request() to
> enqueue a request. In the normal case (i.e the queue isn't full), this
> function returns -EINPROGRESS. The current Marvell CESA crypto driver
> takes this into account and cleans up the request only if an error
> occured, i.e if the return value is not -EINPROGRESS.
>
> Unfortunately this causes problems with
> CRYPTO_TFM_REQ_MAY_BACKLOG-flagged requests. When such a request is
> passed to crypto_enqueue_request() and the queue is full,
> crypto_enqueue_request() will return -EBUSY, but will keep the request
> enqueued nonetheless. This situation was not properly handled by the
> Marvell CESA driver, which was anyway cleaning up the request in such
> a situation. When later on the request was taken out of the backlog
> and actually processed, a kernel crash occured due to the internal
> driver data structures for this structure having been cleaned up.
>
> To avoid this situation, this commit adds a
> mv_cesa_req_needs_cleanup() helper function which indicates if the
> request needs to be cleaned up or not after a call to
> crypto_enqueue_request(). This helper allows to do the cleanup only in
> the appropriate cases, and all call sites of mv_cesa_queue_req() are
> fixed to use this new helper function.
>
> Reported-by: Vincent Donnefort <[email protected]>
> Fixes: db509a45339fd ("crypto: marvell/cesa - add TDMA support")
> Cc: <[email protected]> # v4.2+
> Signed-off-by: Thomas Petazzoni <[email protected]>
> ---
> drivers/crypto/marvell/cesa.h | 27 +++++++++++++++++++++++++++
> drivers/crypto/marvell/cipher.c | 7 +++----
> drivers/crypto/marvell/hash.c | 8 +++-----
> 3 files changed, 33 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/crypto/marvell/cesa.h b/drivers/crypto/marvell/cesa.h
> index b60698b..bc2a55b 100644
> --- a/drivers/crypto/marvell/cesa.h
> +++ b/drivers/crypto/marvell/cesa.h
> @@ -687,6 +687,33 @@ static inline u32 mv_cesa_get_int_mask(struct mv_cesa_engine *engine)
>
> int mv_cesa_queue_req(struct crypto_async_request *req);
>
> +/*
> + * Helper function that indicates whether a crypto request needs to be
> + * cleaned up or not after being enqueued using mv_cesa_queue_req().
> + */
> +static inline int mv_cesa_req_needs_cleanup(struct crypto_async_request *req,
> + int ret)
> +{
> + /*
> + * The queue still had some space, the request was queued
> + * normally, so there's no need to clean it up.
> + */
> + if (ret == -EINPROGRESS)
> + return false;
> +
> + /*
> + * The queue had not space left, but since the request is
> + * flagged with CRYPTO_TFM_REQ_MAY_BACKLOG, it was added to
> + * the backlog and will be processed later. There's no need to
> + * clean it up.
> + */
> + if (ret == -EBUSY && req->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)
> + return false;
> +
> + /* Request wasn't queued, we need to clean it up */
> + return true;
> +}
> +
> /* TDMA functions */
>
> static inline void mv_cesa_req_dma_iter_init(struct mv_cesa_dma_iter *iter,
> diff --git a/drivers/crypto/marvell/cipher.c b/drivers/crypto/marvell/cipher.c
> index 0745cf3..3df2f4e 100644
> --- a/drivers/crypto/marvell/cipher.c
> +++ b/drivers/crypto/marvell/cipher.c
> @@ -189,7 +189,6 @@ static inline void mv_cesa_ablkcipher_prepare(struct crypto_async_request *req,
> {
> struct ablkcipher_request *ablkreq = ablkcipher_request_cast(req);
> struct mv_cesa_ablkcipher_req *creq = ablkcipher_request_ctx(ablkreq);
> -
> creq->req.base.engine = engine;
>
> if (creq->req.base.type == CESA_DMA_REQ)
> @@ -431,7 +430,7 @@ static int mv_cesa_des_op(struct ablkcipher_request *req,
> return ret;
>
> ret = mv_cesa_queue_req(&req->base);
> - if (ret && ret != -EINPROGRESS)
> + if (mv_cesa_req_needs_cleanup(&req->base, ret))
> mv_cesa_ablkcipher_cleanup(req);
>
> return ret;
> @@ -551,7 +550,7 @@ static int mv_cesa_des3_op(struct ablkcipher_request *req,
> return ret;
>
> ret = mv_cesa_queue_req(&req->base);
> - if (ret && ret != -EINPROGRESS)
> + if (mv_cesa_req_needs_cleanup(&req->base, ret))
> mv_cesa_ablkcipher_cleanup(req);
>
> return ret;
> @@ -693,7 +692,7 @@ static int mv_cesa_aes_op(struct ablkcipher_request *req,
> return ret;
>
> ret = mv_cesa_queue_req(&req->base);
> - if (ret && ret != -EINPROGRESS)
> + if (mv_cesa_req_needs_cleanup(&req->base, ret))
> mv_cesa_ablkcipher_cleanup(req);
>
> return ret;
> diff --git a/drivers/crypto/marvell/hash.c b/drivers/crypto/marvell/hash.c
> index ae9272e..e8d0d71 100644
> --- a/drivers/crypto/marvell/hash.c
> +++ b/drivers/crypto/marvell/hash.c
> @@ -739,10 +739,8 @@ static int mv_cesa_ahash_update(struct ahash_request *req)
> return 0;
>
> ret = mv_cesa_queue_req(&req->base);
> - if (ret && ret != -EINPROGRESS) {
> + if (mv_cesa_req_needs_cleanup(&req->base, ret))
> mv_cesa_ahash_cleanup(req);
> - return ret;
> - }
>
> return ret;
> }
> @@ -766,7 +764,7 @@ static int mv_cesa_ahash_final(struct ahash_request *req)
> return 0;
>
> ret = mv_cesa_queue_req(&req->base);
> - if (ret && ret != -EINPROGRESS)
> + if (mv_cesa_req_needs_cleanup(&req->base, ret))
> mv_cesa_ahash_cleanup(req);
>
> return ret;
> @@ -791,7 +789,7 @@ static int mv_cesa_ahash_finup(struct ahash_request *req)
> return 0;
>
> ret = mv_cesa_queue_req(&req->base);
> - if (ret && ret != -EINPROGRESS)
> + if (mv_cesa_req_needs_cleanup(&req->base, ret))
> mv_cesa_ahash_cleanup(req);
>
> return ret;
> --
> 2.5.2
>

2015-09-21 15:05:06

by Herbert Xu

[permalink] [raw]
Subject: Re: [PATCH] crypto: marvell: properly handle CRYPTO_TFM_REQ_MAY_BACKLOG-flagged requests

On Fri, Sep 18, 2015 at 05:25:36PM +0200, Thomas Petazzoni wrote:
> The mv_cesa_queue_req() function calls crypto_enqueue_request() to
> enqueue a request. In the normal case (i.e the queue isn't full), this
> function returns -EINPROGRESS. The current Marvell CESA crypto driver
> takes this into account and cleans up the request only if an error
> occured, i.e if the return value is not -EINPROGRESS.
>
> Unfortunately this causes problems with
> CRYPTO_TFM_REQ_MAY_BACKLOG-flagged requests. When such a request is
> passed to crypto_enqueue_request() and the queue is full,
> crypto_enqueue_request() will return -EBUSY, but will keep the request
> enqueued nonetheless. This situation was not properly handled by the
> Marvell CESA driver, which was anyway cleaning up the request in such
> a situation. When later on the request was taken out of the backlog
> and actually processed, a kernel crash occured due to the internal
> driver data structures for this structure having been cleaned up.
>
> To avoid this situation, this commit adds a
> mv_cesa_req_needs_cleanup() helper function which indicates if the
> request needs to be cleaned up or not after a call to
> crypto_enqueue_request(). This helper allows to do the cleanup only in
> the appropriate cases, and all call sites of mv_cesa_queue_req() are
> fixed to use this new helper function.
>
> Reported-by: Vincent Donnefort <[email protected]>
> Fixes: db509a45339fd ("crypto: marvell/cesa - add TDMA support")
> Cc: <[email protected]> # v4.2+
> Signed-off-by: Thomas Petazzoni <[email protected]>

Applied to crypto.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt