From: "M'boumba Cedric Madianga" <cedric.madianga@gmail.com>
To: vinod.koul@intel.com, robh+dt@kernel.org, mark.rutland@arm.com,
mcoquelin.stm32@gmail.com, alexandre.torgue@st.com,
dan.j.williams@intel.com, dmaengine@vger.kernel.org,
devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Cc: "M'boumba Cedric Madianga" <cedric.madianga@gmail.com>
Subject: [PATCH 4/9] dmaengine: stm32-dma: Fix null pointer dereference in stm32_dma_tx_status
Date: Tue, 13 Dec 2016 14:40:46 +0100 [thread overview]
Message-ID: <1481636451-27863-5-git-send-email-cedric.madianga@gmail.com> (raw)
In-Reply-To: <1481636451-27863-1-git-send-email-cedric.madianga@gmail.com>
chan->desc is always set to NULL when a DMA transfer is complete.
As a DMA transfer could be complete during the call of stm32_dma_tx_status,
we need to be sure that chan->desc is not NULL before using this variable
to avoid a null pointer deference issue.
Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Reviewed-by: Ludovic BARRE <ludovic.barre@st.com>
---
drivers/dma/stm32-dma.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index a884b85..3056ce7 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -880,7 +880,7 @@ static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
struct virt_dma_desc *vdesc;
enum dma_status status;
unsigned long flags;
- u32 residue;
+ u32 residue = 0;
status = dma_cookie_status(c, cookie, state);
if ((status == DMA_COMPLETE) || (!state))
@@ -888,16 +888,12 @@ static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
spin_lock_irqsave(&chan->vchan.lock, flags);
vdesc = vchan_find_desc(&chan->vchan, cookie);
- if (cookie == chan->desc->vdesc.tx.cookie) {
+ if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
residue = stm32_dma_desc_residue(chan, chan->desc,
chan->next_sg);
- } else if (vdesc) {
+ else if (vdesc)
residue = stm32_dma_desc_residue(chan,
to_stm32_dma_desc(vdesc), 0);
- } else {
- residue = 0;
- }
-
dma_set_residue(state, residue);
spin_unlock_irqrestore(&chan->vchan.lock, flags);
--
1.9.1
next prev parent reply other threads:[~2016-12-13 13:43 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-13 13:40 [PATCH 0/9] dmaengine: stm32-dma: Bug fixes and improvements series M'boumba Cedric Madianga
2016-12-13 13:40 ` [PATCH 1/9] dmaengine: stm32-dma: Set correct args number for DMA request from DT M'boumba Cedric Madianga
2016-12-13 13:40 ` [PATCH 2/9] dmaengine: stm32-dma: Fix typo in Kconfig M'boumba Cedric Madianga
2016-12-13 13:40 ` [PATCH 3/9] dt-bindings: stm32-dma: Fix typo regarding DMA client binding M'boumba Cedric Madianga
2016-12-13 20:09 ` Rob Herring
2016-12-13 13:40 ` M'boumba Cedric Madianga [this message]
2016-12-13 13:40 ` [PATCH 5/9] dmaengine: stm32-dma: Rework starting transfer management M'boumba Cedric Madianga
2016-12-13 13:40 ` [PATCH 6/9] dmaengine: stm32-dma: Fix residue computation issue in cyclic mode M'boumba Cedric Madianga
2016-12-13 13:40 ` [PATCH 7/9] dmaengine: stm32-dma: Add error messages if xlate fails M'boumba Cedric Madianga
2016-12-13 13:40 ` [PATCH 8/9] dmaengine: stm32-dma: Add synchronization support M'boumba Cedric Madianga
2016-12-13 13:40 ` [PATCH 9/9] dmaengine: stm32-dma: Add max_burst support M'boumba Cedric Madianga
2017-01-02 4:14 ` [PATCH 0/9] dmaengine: stm32-dma: Bug fixes and improvements series Vinod Koul
2017-01-02 9:26 ` M'boumba Cedric Madianga
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