2018-09-17 15:11:49

by Christoph Manszewski

Subject: [PATCH v2 1/4] crypto: s5p-sss: Fix race in error handling

Remove a race condition introduced by error path in functions:
s5p_aes_interrupt and s5p_aes_crypt_start. Setting the busy field of
struct s5p_aes_dev to false made it possible for s5p_tasklet_cb to
change the req field, before s5p_aes_complete was called.

Change the first parameter of s5p_aes_complete to struct
ablkcipher_request. Before spin_unlock, make a copy of the currently
handled request, to ensure s5p_aes_complete function call with the
correct request.

Signed-off-by: Christoph Manszewski <[email protected]>
---
drivers/crypto/s5p-sss.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/crypto/s5p-sss.c b/drivers/crypto/s5p-sss.c
index faa282074e5a..9021ad9df0c4 100644
--- a/drivers/crypto/s5p-sss.c
+++ b/drivers/crypto/s5p-sss.c
@@ -475,9 +475,9 @@ static void s5p_sg_done(struct s5p_aes_dev *dev)
}

/* Calls the completion. Cannot be called with dev->lock hold. */
-static void s5p_aes_complete(struct s5p_aes_dev *dev, int err)
+static void s5p_aes_complete(struct ablkcipher_request *req, int err)
{
- dev->req->base.complete(&dev->req->base, err);
+ req->base.complete(&req->base, err);
}

static void s5p_unset_outdata(struct s5p_aes_dev *dev)
@@ -655,6 +655,7 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id)
{
struct platform_device *pdev = dev_id;
struct s5p_aes_dev *dev = platform_get_drvdata(pdev);
+ struct ablkcipher_request *req;
int err_dma_tx = 0;
int err_dma_rx = 0;
int err_dma_hx = 0;
@@ -727,7 +728,7 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id)

spin_unlock_irqrestore(&dev->lock, flags);

- s5p_aes_complete(dev, 0);
+ s5p_aes_complete(dev->req, 0);
/* Device is still busy */
tasklet_schedule(&dev->tasklet);
} else {
@@ -752,11 +753,12 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id)
error:
s5p_sg_done(dev);
dev->busy = false;
+ req = dev->req;
if (err_dma_hx == 1)
s5p_set_dma_hashdata(dev, dev->hash_sg_iter);

spin_unlock_irqrestore(&dev->lock, flags);
- s5p_aes_complete(dev, err);
+ s5p_aes_complete(req, err);

hash_irq_end:
/*
@@ -1983,7 +1985,7 @@ static void s5p_aes_crypt_start(struct s5p_aes_dev *dev, unsigned long mode)
s5p_sg_done(dev);
dev->busy = false;
spin_unlock_irqrestore(&dev->lock, flags);
- s5p_aes_complete(dev, err);
+ s5p_aes_complete(req, err);
}

static void s5p_tasklet_cb(unsigned long data)
--
2.7.4

2018-09-17 15:54:50

by Kamil Konieczny

Subject: Re: [PATCH v2 1/4] crypto: s5p-sss: Fix race in error handling

On 17.09.2018 17:09, Christoph Manszewski wrote:
> Remove a race condition introduced by error path in functions:
> s5p_aes_interrupt and s5p_aes_crypt_start. Setting the busy field of
> struct s5p_aes_dev to false made it possible for s5p_tasklet_cb to
> change the req field, before s5p_aes_complete was called.
>
> Change the first parameter of s5p_aes_complete to struct
> ablkcipher_request. Before spin_unlock, make a copy of the currently
> handled request, to ensure s5p_aes_complete function call with the
> correct request.
>
> Signed-off-by: Christoph Manszewski <[email protected]>

Acked-by: Kamil Konieczny <[email protected]>

Thanks!
Kamil

--
Best regards,
Kamil Konieczny
Samsung R&D Institute Poland

2018-09-18 07:36:29

by Krzysztof Kozlowski

Subject: Re: [PATCH v2 1/4] crypto: s5p-sss: Fix race in error handling

On Mon, 17 Sep 2018 at 17:10, Christoph Manszewski
<[email protected]> wrote:
>
> Remove a race condition introduced by error path in functions:
> s5p_aes_interrupt and s5p_aes_crypt_start. Setting the busy field of
> struct s5p_aes_dev to false made it possible for s5p_tasklet_cb to
> change the req field, before s5p_aes_complete was called.
>
> Change the first parameter of s5p_aes_complete to struct
> ablkcipher_request. Before spin_unlock, make a copy of the currently
> handled request, to ensure s5p_aes_complete function call with the
> correct request.
>
> Signed-off-by: Christoph Manszewski <[email protected]>
> ---
> drivers/crypto/s5p-sss.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)

Reviewed-by: Krzysztof Kozlowski <[email protected]>

Best regards,
Krzysztof