libertas: move firmware lifetime handling to firmware.c

Previously, each bus type was responsible for freeing the firmware
structure, but some did that badly.  Move responsibility for freeing
firmware into firmware.c so that it's done once and correctly, instead
of happening in multiple places in bus-specific code.

This fixes a use-after-free bug found by Dr. H. Nikolaus Schaller where
the SDIO code forgot to NULL priv->helper_fw after freeing it.

Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

5 files changed, 16 insertions, 26 deletions

diff --git a/drivers/net/wireless/libertas/firmware.c b/drivers/net/wireless/libertas/firmware.c
index c0f9e7e..51b92b5 100644
--- a/drivers/net/wireless/libertas/firmware.c
+++ b/drivers/net/wireless/libertas/firmware.c
@@ -53,6 +53,11 @@ static void main_firmware_cb(const struct firmware *firmware, void *context)
 
 	/* Firmware found! */
 	lbs_fw_loaded(priv, 0, priv->helper_fw, firmware);
+	if (priv->helper_fw) {
+		release_firmware (priv->helper_fw);
+		priv->helper_fw = NULL;
+	}
+	release_firmware (firmware);
 }
 
 static void helper_firmware_cb(const struct firmware *firmware, void *context)
diff --git a/drivers/net/wireless/libertas/if_cs.c b/drivers/net/wireless/libertas/if_cs.c
index c94dd68..ef8c98e 100644
--- a/drivers/net/wireless/libertas/if_cs.c
+++ b/drivers/net/wireless/libertas/if_cs.c
@@ -754,14 +754,14 @@ static void if_cs_prog_firmware(struct lbs_private *priv, int ret,
 	if (ret == 0 && (card->model != MODEL_8305))
 		ret = if_cs_prog_real(card, mainfw);
 	if (ret)
-		goto out;
+		return;
 
 	/* Now actually get the IRQ */
 	ret = request_irq(card->p_dev->irq, if_cs_interrupt,
 		IRQF_SHARED, DRV_NAME, card);
 	if (ret) {
 		pr_err("error in request_irq\n");
-		goto out;
+		return;
 	}
 
 	/*
@@ -777,10 +777,6 @@ static void if_cs_prog_firmware(struct lbs_private *priv, int ret,
 		pr_err("could not activate card\n");
 		free_irq(card->p_dev->irq, card);
 	}
-
-out:
-	release_firmware(helper);
-	release_firmware(mainfw);
 }
 
 
diff --git a/drivers/net/wireless/libertas/if_sdio.c b/drivers/net/wireless/libertas/if_sdio.c
index 4557833..991238a 100644
--- a/drivers/net/wireless/libertas/if_sdio.c
+++ b/drivers/net/wireless/libertas/if_sdio.c
@@ -708,20 +708,16 @@ static void if_sdio_do_prog_firmware(struct lbs_private *priv, int ret,
 
 	ret = if_sdio_prog_helper(card, helper);
 	if (ret)
-		goto out;
+		return;
 
 	lbs_deb_sdio("Helper firmware loaded\n");
 
 	ret = if_sdio_prog_real(card, mainfw);
 	if (ret)
-		goto out;
+		return;
 
 	lbs_deb_sdio("Firmware loaded\n");
 	if_sdio_finish_power_on(card);
-
-out:
-	release_firmware(helper);
-	release_firmware(mainfw);
 }
 
 static int if_sdio_prog_firmware(struct if_sdio_card *card)
diff --git a/drivers/net/wireless/libertas/if_spi.c b/drivers/net/wireless/libertas/if_spi.c
index 5d39ec8..8366915 100644
--- a/drivers/net/wireless/libertas/if_spi.c
+++ b/drivers/net/wireless/libertas/if_spi.c
@@ -1094,11 +1094,7 @@ static int if_spi_init_card(struct if_spi_card *card)
 		goto out;
 
 out:
-	release_firmware(helper);
-	release_firmware(mainfw);
-
 	lbs_deb_leave_args(LBS_DEB_SPI, "err %d\n", err);
-
 	return err;
 }
 
diff --git a/drivers/net/wireless/libertas/if_usb.c b/drivers/net/wireless/libertas/if_usb.c
index 2798077..dff08a2 100644
--- a/drivers/net/wireless/libertas/if_usb.c
+++ b/drivers/net/wireless/libertas/if_usb.c
@@ -844,7 +844,7 @@ static void if_usb_prog_firmware(struct lbs_private *priv, int ret,
 	cardp->fw = fw;
 	if (check_fwfile_format(cardp->fw->data, cardp->fw->size)) {
 		ret = -EINVAL;
-		goto release_fw;
+		goto done;
 	}
 
 	/* Cancel any pending usb business */
@@ -861,7 +861,7 @@ restart:
 	if (if_usb_submit_rx_urb_fwload(cardp) < 0) {
 		lbs_deb_usbd(&cardp->udev->dev, "URB submission is failed\n");
 		ret = -EIO;
-		goto release_fw;
+		goto done;
 	}
 
 	cardp->bootcmdresp = 0;
@@ -883,14 +883,14 @@ restart:
 		usb_kill_urb(cardp->tx_urb);
 		if (if_usb_submit_rx_urb(cardp) < 0)
 			ret = -EIO;
-		goto release_fw;
+		goto done;
 	} else if (cardp->bootcmdresp <= 0) {
 		if (--reset_count >= 0) {
 			if_usb_reset_device(cardp);
 			goto restart;
 		}
 		ret = -EIO;
-		goto release_fw;
+		goto done;
 	}
 
 	i = 0;
@@ -921,14 +921,14 @@ restart:
 
 		pr_info("FW download failure, time = %d ms\n", i * 100);
 		ret = -EIO;
-		goto release_fw;
+		goto done;
 	}
 
 	cardp->priv->fw_ready = 1;
 	if_usb_submit_rx_urb(cardp);
 
 	if (lbs_start_card(priv))
-		goto release_fw;
+		goto done;
 
 	if_usb_setup_firmware(priv);
 
@@ -939,11 +939,8 @@ restart:
 	if (lbs_host_sleep_cfg(priv, priv->wol_criteria, NULL))
 		priv->ehs_remove_supported = false;
 
- release_fw:
-	release_firmware(cardp->fw);
-	cardp->fw = NULL;
-
  done:
+	cardp->fw = NULL;
 	lbs_deb_leave(LBS_DEB_USB);
 }