net: ieee802154: fix potential null pointer dereference

GustavoARSilva · holtmann · commit 7dab5467647b · 2017-05-23T20:12:53.000+02:00
Null check at line 918: if (!spi) {, implies spi might be NULL.
Function spi_get_drvdata() dereference pointer spi.
Move pointer priv assignment after the null check.

Addresses-Coverity-ID: 1408888
Signed-off-by: Gustavo A. R. Silva &lt;garsilva@embeddedor.com&gt;
Signed-off-by: Marcel Holtmann &lt;marcel@holtmann.org&gt;
diff --git a/drivers/net/ieee802154/ca8210.c b/drivers/net/ieee802154/ca8210.c
@@ -912,7 +912,7 @@ static int ca8210_spi_transfer(
 )
 {
 	int i, status = 0;
-	struct ca8210_priv *priv = spi_get_drvdata(spi);
+	struct ca8210_priv *priv;
 	struct cas_control *cas_ctl;
 
 	if (!spi) {
@@ -923,6 +923,7 @@ static int ca8210_spi_transfer(
 		return -ENODEV;
 	}
 
+	priv = spi_get_drvdata(spi);
 	reinit_completion(&priv->spi_transfer_complete);
 
 	dev_dbg(&spi->dev, "ca8210_spi_transfer called\n");

Original file line number	Diff line number	Diff line change
`@@ -912,7 +912,7 @@ static int ca8210_spi_transfer(`
`912`	`912`	`)`
`913`	`913`	`{`
`914`	`914`	`int i, status = 0;`
`915`		`- struct ca8210_priv *priv = spi_get_drvdata(spi);`
	`915`	`+ struct ca8210_priv *priv;`
`916`	`916`	`struct cas_control *cas_ctl;`
`917`	`917`
`918`	`918`	`if (!spi) {`
`@@ -923,6 +923,7 @@ static int ca8210_spi_transfer(`
`923`	`923`	`return -ENODEV;`
`924`	`924`	`}`
`925`	`925`
	`926`	`+ priv = spi_get_drvdata(spi);`
`926`	`927`	`reinit_completion(&priv->spi_transfer_complete);`
`927`	`928`
`928`	`929`	`dev_dbg(&spi->dev, "ca8210_spi_transfer called\n");`