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authorLogan Gunthorpe <logang@deltatee.com>2019-12-16 12:01:17 -0700
committerVinod Koul <vkoul@kernel.org>2019-12-24 10:18:32 +0530
commit686607106f1fe163f7d017561f3622f39a291de8 (patch)
tree2d5a7cc744353c15e6f89b119b58a80c5ea3d2f6 /drivers/dma/dmaengine.c
parentdae7a589c18a4d979d5f14b09374e871b995ceb1 (diff)
dmaengine: Call module_put() after device_free_chan_resources()
The module reference is taken to ensure the callbacks still exist when they are called. If the channel holds the last reference to the module, the module can disappear before device_free_chan_resources() is called and would cause a call into free'd memory. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Link: https://lore.kernel.org/r/20191216190120.21374-3-logang@deltatee.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma/dmaengine.c')
-rw-r--r--drivers/dma/dmaengine.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 4b604086b1b3..776fdf535a3a 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -250,7 +250,6 @@ static void dma_chan_put(struct dma_chan *chan)
return;
chan->client_count--;
- module_put(dma_chan_to_owner(chan));
/* This channel is not in use anymore, free it */
if (!chan->client_count && chan->device->device_free_chan_resources) {
@@ -259,6 +258,8 @@ static void dma_chan_put(struct dma_chan *chan)
chan->device->device_free_chan_resources(chan);
}
+ module_put(dma_chan_to_owner(chan));
+
/* If the channel is used via a DMA request router, free the mapping */
if (chan->router && chan->router->route_free) {
chan->router->route_free(chan->router->dev, chan->route_data);