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SPI omap2_mcspi.c: Check params before dereference or use

PATCH In review Scott Ellis 3 participants 4 messages Mar 12, 2010 – May 25, 2010 1 message not in the archive SPI

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Scott Ellis

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#0 lore raw

PATCH 1/6 SPI omap2_mcspi.c: Check params before dereference or use

This was previously submitted directly to the linux-kernel list. It was incomplete the first time because it failed to also check the chip_select value.

Check spi->controller_state before dereference.
Check spi->chip_select for range before use.

Neither are necessarily valid after spi_alloc_device() and then spi_add_device() fails. Calling spi_put_device() will trigger the error.

Signed-off-by Scott Ellis <[email protected]>
 drivers/spi/omap2_mcspi.c |   30 +++++++++++++++++-------------
 1 files changed, 17 insertions(+), 13 deletions(-)
drivers/spi/omap2_mcspi.c +17 -13
index 715c518..fe1b56d 100644
@@ -748,22 +748,26 @@ static void omap2_mcspi_cleanup(struct spi_device *spi)
 	struct omap2_mcspi_dma	*mcspi_dma;
 	struct omap2_mcspi_cs	*cs;
 
-	mcspi = spi_master_get_devdata(spi->master);
-	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
+	if (spi->controller_state) {
+		/* Unlink controller state from context save list */
+		cs = spi->controller_state;
+		list_del(&cs->node);
 
-	/* Unlink controller state from context save list */
-	cs = spi->controller_state;
-	list_del(&cs->node);
+		kfree(spi->controller_state);
+	}
 
-	kfree(spi->controller_state);
+	if (spi->chip_select < spi->master->num_chipselect) {
+		mcspi = spi_master_get_devdata(spi->master);
+		mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 
-	if (mcspi_dma->dma_rx_channel != -1) {
-		omap_free_dma(mcspi_dma->dma_rx_channel);
-		mcspi_dma->dma_rx_channel = -1;
-	}
-	if (mcspi_dma->dma_tx_channel != -1) {
-		omap_free_dma(mcspi_dma->dma_tx_channel);
-		mcspi_dma->dma_tx_channel = -1;
+		if (mcspi_dma->dma_rx_channel != -1) {
+			omap_free_dma(mcspi_dma->dma_rx_channel);
+			mcspi_dma->dma_rx_channel = -1;
+		}
+		if (mcspi_dma->dma_tx_channel != -1) {
+			omap_free_dma(mcspi_dma->dma_tx_channel);
+			mcspi_dma->dma_tx_channel = -1;
+		}
 	}
 }
#1 lore raw
Quoted 4 lines · Scott Ellis

This was previously submitted directly to the linux-kernel list. It was incomplete the first time because it failed to also check the chip_select value.

Quoted 8 lines

Check spi->controller_state before dereference.
Check spi->chip_select for range before use.

Neither are necessarily valid after spi_alloc_device() and then spi_add_device() fails. Calling spi_put_device() will trigger the error.

Signed-off-by Scott Ellis <[email protected]>

Hi Scott,

Can you please respin and repost your pending patches on top of 2.6.34? The current patches don't apply as-is and I've lost track of what needs to be done.

Thanks,
g.

Quoted 56 lines

 drivers/spi/omap2_mcspi.c |   30 +++++++++++++++++-------------

 1 files changed, 17 insertions(+), 13 deletions(-)
drivers/spi/omap2_mcspi.c +17 -13
index 715c518..fe1b56d 100644
@@ -748,22 +748,26 @@ static void omap2_mcspi_cleanup(struct spi_device *spi)
        struct omap2_mcspi_dma  *mcspi_dma;
        struct omap2_mcspi_cs   *cs;
 
-       mcspi = spi_master_get_devdata(spi->master);
-       mcspi_dma = &mcspi->dma_channels[spi->chip_select];
+       if (spi->controller_state) {
+               /* Unlink controller state from context save list */
+               cs = spi->controller_state;
+               list_del(&cs->node);
 
-       /* Unlink controller state from context save list */
-       cs = spi->controller_state;
-       list_del(&cs->node);
+               kfree(spi->controller_state);
+       }
 
-       kfree(spi->controller_state);
+       if (spi->chip_select < spi->master->num_chipselect) {
+               mcspi = spi_master_get_devdata(spi->master);
+               mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 
-       if (mcspi_dma->dma_rx_channel != -1) {
-               omap_free_dma(mcspi_dma->dma_rx_channel);
-               mcspi_dma->dma_rx_channel = -1;
-       }
-       if (mcspi_dma->dma_tx_channel != -1) {
-               omap_free_dma(mcspi_dma->dma_tx_channel);
-               mcspi_dma->dma_tx_channel = -1;
+               if (mcspi_dma->dma_rx_channel != -1) {
+                       omap_free_dma(mcspi_dma->dma_rx_channel);
+                       mcspi_dma->dma_rx_channel = -1;
+               }
+               if (mcspi_dma->dma_tx_channel != -1) {
+                       omap_free_dma(mcspi_dma->dma_tx_channel);
+                       mcspi_dma->dma_tx_channel = -1;
+               }
        }
  }
Signature · 6 lines
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
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#3 lore raw

Check spi->chip_select for range before use.

The spi->controller_state check is already in 2.6.34-rc7

Signed-off-by Scott Ellis <scott-oZqG5KApg2M/[email protected]>
 drivers/spi/omap2_mcspi.c |   19 +++++++++++--------
 1 files changed, 11 insertions(+), 8 deletions(-)
drivers/spi/omap2_mcspi.c +0 -0
index e0de0d0..0b35468 100644
@@ -755,7 +755,6 @@ static void omap2_mcspi_cleanup(struct spi_device

*spi)
struct omap2_mcspi_cs *cs;

mcspi = spi_master_get_devdata(spi->master);
- mcspi_dma = &mcspi->dma_channels[spi->chip_select];

if (spi->controller_state) {
/* Unlink controller state from context save list */
@@ -765,13 +764,17 @@ static void omap2_mcspi_cleanup(struct spi_device *spi)
kfree(spi->controller_state);
}

- if (mcspi_dma->dma_rx_channel != -1) {
- omap_free_dma(mcspi_dma->dma_rx_channel);
- mcspi_dma->dma_rx_channel = -1;
- }
- if (mcspi_dma->dma_tx_channel != -1) {
- omap_free_dma(mcspi_dma->dma_tx_channel);
- mcspi_dma->dma_tx_channel = -1;
+ if (spi->chip_select < spi->master->num_chipselect) {
+ mcspi_dma = &mcspi->dma_channels[spi->chip_select];
+
+ if (mcspi_dma->dma_rx_channel != -1) {
+ omap_free_dma(mcspi_dma->dma_rx_channel);
+ mcspi_dma->dma_rx_channel = -1;
+ }
+ if (mcspi_dma->dma_tx_channel != -1) {
+ omap_free_dma(mcspi_dma->dma_tx_channel);
+ mcspi_dma->dma_tx_channel = -1;
+ }
}
}

------------------------------------------------------------------------------

#4 lore raw
Quoted 5 lines · Scott Ellis

Check spi->chip_select for range before use.

The spi->controller_state check is already in 2.6.34-rc7

Signed-off-by Scott Ellis <[email protected]>

Okay, I've pick up this patch, but please check your Evolution configuration. Patchwork seems to be barfing on the patches sent by you. My guess is that it relies on a "---" line between the last "signed-off-by", and the start of the actual patch. See here to see what I'm talking about:

https://patchwork.kernel.org/patch/101890/

Cheers,
g.

Quoted 44 lines

 drivers/spi/omap2_mcspi.c |   19 +++++++++++--------

 1 files changed, 11 insertions(+), 8 deletions(-)
drivers/spi/omap2_mcspi.c +0 -1
index e0de0d0..0b35468 100644
@@ -755,7 +755,6 @@ static void omap2_mcspi_cleanup(struct spi_device
 *spi)
        struct omap2_mcspi_cs   *cs;
 
        mcspi = spi_master_get_devdata(spi->master);
-       mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 
        if (spi->controller_state) {

               /* Unlink controller state from context save list */

drivers/spi/omap2_mcspi.c +11 -7
@@ -765,13 +764,17 @@ static void omap2_mcspi_cleanup(struct spi_device
 *spi)
                kfree(spi->controller_state);
        }
 
-       if (mcspi_dma->dma_rx_channel != -1) {
-               omap_free_dma(mcspi_dma->dma_rx_channel);
-               mcspi_dma->dma_rx_channel = -1;
-       }
-       if (mcspi_dma->dma_tx_channel != -1) {
-               omap_free_dma(mcspi_dma->dma_tx_channel);
-               mcspi_dma->dma_tx_channel = -1;
+       if (spi->chip_select < spi->master->num_chipselect) {
+               mcspi_dma = &mcspi->dma_channels[spi->chip_select];
+
+               if (mcspi_dma->dma_rx_channel != -1) {
+                       omap_free_dma(mcspi_dma->dma_rx_channel);
+                       mcspi_dma->dma_rx_channel = -1;
+               }
+               if (mcspi_dma->dma_tx_channel != -1) {
+                       omap_free_dma(mcspi_dma->dma_tx_channel);
+                       mcspi_dma->dma_tx_channel = -1;
+               }
        }
  }
Signature · 6 lines
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
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