Jan 30 2011

wl12xx: fix use after free 

Author: Mathias Krause <minipli@googlemail.com>

When DEBUG_SPI is included in the debug log level wl1271_spi_reset()
will dump the already freed memory instead of the SPI buffer.

This bug was spotted by the semantic patch tool coccinelle using the
script found at scripts/coccinelle/free/kfree.cocci.

More information about semantic patching is available at
http://coccinelle.lip6.fr/

Signed-off-by: Mathias Krause 
Signed-off-by: John W. Linville 

---
 drivers/net/wireless/wl12xx/spi.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
 
diff --git a/drivers/net/wireless/wl12xx/spi.c b/drivers/net/wireless/wl12xx/spi.c
index 4671491..7145ea5 100644
--- a/drivers/net/wireless/wl12xx/spi.c
+++ b/drivers/net/wireless/wl12xx/spi.c
@@ -110,9 +110,8 @@ static void wl1271_spi_reset(struct wl1271 *wl)
 	spi_message_add_tail(&t, &m);
 
 	spi_sync(wl_to_spi(wl), &m);
-	kfree(cmd);
-
 	wl1271_dump(DEBUG_SPI, "spi reset -> ", cmd, WSPI_INIT_CMD_LEN);
+	kfree(cmd);
 }
 
 static void wl1271_spi_init(struct wl1271 *wl)

qlambert