From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
        Jakub Kicinski <kuba@kernel.org>
Subject: [PATCH 5.10 027/132] nfc: fix potential NULL pointer deref in nfc_genl_dump_ses_done
Date:   Mon, 13 Dec 2021 10:29:28 +0100
Message-Id: <20211213092940.036240342@linuxfoundation.org>
In-Reply-To: <20211213092939.074326017@linuxfoundation.org>
References: <20211213092939.074326017@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

commit 4cd8371a234d051f9c9557fcbb1f8c523b1c0d10 upstream.

The done() netlink callback nfc_genl_dump_ses_done() should check if
received argument is non-NULL, because its allocation could fail earlier
in dumpit() (nfc_genl_dump_ses()).

Fixes: ac22ac466a65 ("NFC: Add a GET_SE netlink API")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211209081307.57337-1-krzysztof.kozlowski@canonical.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/nfc/netlink.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -1392,8 +1392,10 @@ static int nfc_genl_dump_ses_done(struct
 {
 	struct class_dev_iter *iter = (struct class_dev_iter *) cb->args[0];
 
-	nfc_device_iter_exit(iter);
-	kfree(iter);
+	if (iter) {
+		nfc_device_iter_exit(iter);
+		kfree(iter);
+	}
 
 	return 0;
 }