diff options
| author |   Dmitry Osipenko <digetx@gmail.com> | 2020-02-09 19:33:39 +0300 |
|---|---|---|
| committer |   Vinod Koul <vkoul@kernel.org> | 2020-02-25 11:57:09 +0530 |
| commit | c33ee1301c393a241d6424e36eff1071811b1064 (patch) | |
| tree | 820e2729f28c84d740298a984bf0e0f65c9e3cf4 /drivers/dma/tegra20-apb-dma.c | |
| parent | dmaengine: tegra-apb: Fix use-after-free (diff) | |
| download | linux-dev-c33ee1301c393a241d6424e36eff1071811b1064.tar.xz linux-dev-c33ee1301c393a241d6424e36eff1071811b1064.zip | |
dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list
The interrupt handler puts a half-completed DMA descriptor on a free list
and then schedules tasklet to process bottom half of the descriptor that
executes client's callback, this creates possibility to pick up the busy
descriptor from the free list. Thus, let's disallow descriptor's re-use
until it is fully processed.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200209163356.6439-3-digetx@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma/tegra20-apb-dma.c')
| -rw-r--r-- | drivers/dma/tegra20-apb-dma.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index 319f31d27014..4a750e29bfb5 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -281,7 +281,7 @@ static struct tegra_dma_desc *tegra_dma_desc_get( /* Do not allocate if desc are waiting for ack */ list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) { - if (async_tx_test_ack(&dma_desc->txd)) { + if (async_tx_test_ack(&dma_desc->txd) && !dma_desc->cb_count) { list_del(&dma_desc->node); spin_unlock_irqrestore(&tdc->lock, flags); dma_desc->txd.flags = 0; |