From 42d5c176b76e190a4a3e0dfeffdae661755955b6 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Fri, 17 Mar 2017 16:49:19 +0200 Subject: [PATCH] crypto: s5p-sss - Close possible race for completed requests Driver is capable of handling only one request at a time and it stores it in its state container struct s5p_aes_dev. This stored request must be protected between concurrent invocations (e.g. completing current request and scheduling new one). Combination of lock and "busy" field is used for that purpose. When "busy" field is true, the driver will not accept new request thus it will not overwrite currently handled data. However commit 28b62b145868 ("crypto: s5p-sss - Fix spinlock recursion on LRW(AES)") moved some of the write to "busy" field out of a lock protected critical section. This might lead to potential race between completing current request and scheduling a new one. Effectively the request completion might try to operate on new crypto request. Cc: # v4.10.x Fixes: 28b62b145868 ("crypto: s5p-sss - Fix spinlock recursion on LRW(AES)") Signed-off-by: Krzysztof Kozlowski Reviewed-by: Bartlomiej Zolnierkiewicz Signed-off-by: Herbert Xu --- drivers/crypto/s5p-sss.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/crypto/s5p-sss.c b/drivers/crypto/s5p-sss.c index 1b9da3dc799b..6c620487e9c2 100644 --- a/drivers/crypto/s5p-sss.c +++ b/drivers/crypto/s5p-sss.c @@ -287,7 +287,6 @@ static void s5p_sg_done(struct s5p_aes_dev *dev) static void s5p_aes_complete(struct s5p_aes_dev *dev, int err) { dev->req->base.complete(&dev->req->base, err); - dev->busy = false; } static void s5p_unset_outdata(struct s5p_aes_dev *dev) @@ -462,7 +461,7 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id) spin_unlock_irqrestore(&dev->lock, flags); s5p_aes_complete(dev, 0); - dev->busy = true; + /* Device is still busy */ tasklet_schedule(&dev->tasklet); } else { /* @@ -483,6 +482,7 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id) error: s5p_sg_done(dev); + dev->busy = false; spin_unlock_irqrestore(&dev->lock, flags); s5p_aes_complete(dev, err); @@ -634,6 +634,7 @@ static void s5p_aes_crypt_start(struct s5p_aes_dev *dev, unsigned long mode) indata_error: s5p_sg_done(dev); + dev->busy = false; spin_unlock_irqrestore(&dev->lock, flags); s5p_aes_complete(dev, err); }