From 049ceac308b0d57c4f06b9fb957cdf95d315cf0b Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Fri, 1 May 2020 18:39:00 +0100
Subject: [PATCH] libertas_tf: avoid a null dereference in pointer priv
Git-commit: 049ceac308b0d57c4f06b9fb957cdf95d315cf0b
Patch-mainline: v5.8-rc1
References: git-fixes

Currently there is a check if priv is null when calling lbtf_remove_card
but not in a previous call to if_usb_reset_dev that can also dereference
priv.  Fix this by also only calling lbtf_remove_card if priv is null.

It is noteable that there don't seem to be any bugs reported that the
null pointer dereference has ever occurred, so I'm not sure if the null
check is required, but since we're doing a null check anyway it should
be done for both function calls.

Addresses-coverity: ("Dereference before null check")
Fixes: baa0280f08c7 ("libertas_tf: don't defer firmware loading until start()")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200501173900.296658-1-colin.king@canonical.com
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/wireless/marvell/libertas_tf/if_usb.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/marvell/libertas_tf/if_usb.c b/drivers/net/wireless/marvell/libertas_tf/if_usb.c
index 25ac9db35dbf..bedc09215088 100644
--- a/drivers/net/wireless/marvell/libertas_tf/if_usb.c
+++ b/drivers/net/wireless/marvell/libertas_tf/if_usb.c
@@ -247,10 +247,10 @@ static void if_usb_disconnect(struct usb_interface *intf)
 
 	lbtf_deb_enter(LBTF_DEB_MAIN);
 
-	if_usb_reset_device(priv);
-
-	if (priv)
+	if (priv) {
+		if_usb_reset_device(priv);
 		lbtf_remove_card(priv);
+	}
 
 	/* Unlink and free urb */
 	if_usb_free(cardp);
-- 
2.16.4