commit 5e7749436d576a525d7b2a4bcffb17b3364b9e00
author Scott Ellis <scott@jumpnowtek.com> Wed Mar 10 14:22:45 2010 -0700
committer Grant Likely <grant.likely@secretlab.ca> Wed Mar 10 14:22:45 2010 -0700
tree 1c7e0c67f0e5cdc49f594afd65204d09a3a8a017
parent 07081fd8587478849b69d7b41596e81ff5a7f532

spi/omap2_mcspi: fix NULL pointer dereference

Check spi->controller_state before dereferencing.

Shows up NULL here when using spi_alloc_device()/spi_add_device()
and spi_add_device() fails before spi_setup(). Calling spi_dev_put()
on the leftover spi_device results in the error.

Signed-off-by: Scott Ellis <scott@jumpnowtek.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

drivers/spi/omap2_mcspi.c

diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
index 715c518..87d44ee 100644
--- a/drivers/spi/omap2_mcspi.c
+++ b/drivers/spi/omap2_mcspi.c
@@ -751,11 +751,13 @@
 	mcspi = spi_master_get_devdata(spi->master);
 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 
-	/* Unlink controller state from context save list */
-	cs = spi->controller_state;
-	list_del(&cs->node);
+	if (spi->controller_state) {
+		/* Unlink controller state from context save list */
+		cs = spi->controller_state;
+		list_del(&cs->node);
 
-	kfree(spi->controller_state);
+		kfree(spi->controller_state);
+	}
 
 	if (mcspi_dma->dma_rx_channel != -1) {
 		omap_free_dma(mcspi_dma->dma_rx_channel);