[PATCH AUTOSEL 4.19 157/191] crypto: s5p-sss: Fix race in error handling

Sasha Levin
2019-11-10T03:09:16Z

From: Christoph Manszewski <c.manszewski@samsung.com>

[ Upstream commit 5842cd44786055231b233ed5ed98cdb63ffb7db3 ]

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 <c.manszewski@samsung.com>
Acked-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 faa282074e5aa..9021ad9df0c45 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)
--
2.20.1