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 <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>

diff --git a/drivers/crypto/s5p-sss.c b/drivers/crypto/s5p-sss.c
index faa282074e5aa4a611b9ee137fc393d3fecc4a3c..9021ad9df0c45d50bb1d81aac616ddd30069a291 100644 (file)
--- 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 @@ indata_error:
        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)