From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gateway30.websitewelcome.com ([192.185.192.34]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1g2GUR-0001Xx-VN for linux-mtd@lists.infradead.org; Tue, 18 Sep 2018 13:56:33 +0000 Received: from cm10.websitewelcome.com (cm10.websitewelcome.com [100.42.49.4]) by gateway30.websitewelcome.com (Postfix) with ESMTP id A0BA4E9A3 for ; Tue, 18 Sep 2018 08:56:17 -0500 (CDT) Date: Tue, 18 Sep 2018 08:55:55 -0500 From: "Gustavo A. R. Silva" To: Tudor Ambarus , Boris Brezillon , Miquel Raynal , Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , Nicolas Ferre , Alexandre Belloni , Ludovic Desroches Cc: linux-mtd@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH v2] mtd: rawnand: atmel: Fix potential NULL pointer dereference Message-ID: <20180918135555.GA18114@embeddedor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , There is a potential execution path in which function of_find_compatible_node() returns NULL. In such a case, we end up having a NULL pointer dereference when accessing pointer *nfc_np* in function of_clk_get(). So, we better don't take any chances and fix this by null checking pointer *nfc_np* before calling of_clk_get(). Addresses-Coverity-ID: 1473052 ("Dereference null return value") Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver") Signed-off-by: Gustavo A. R. Silva --- Changes in v2: - Add Fixes tag to the commit log. - Remove blank line before null checking nfc_np. drivers/mtd/nand/raw/atmel/nand-controller.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c index a38633a..5bfbe97 100644 --- a/drivers/mtd/nand/raw/atmel/nand-controller.c +++ b/drivers/mtd/nand/raw/atmel/nand-controller.c @@ -2034,6 +2034,10 @@ atmel_hsmc_nand_controller_legacy_init(struct atmel_hsmc_nand_controller *nc) nand_np = dev->of_node; nfc_np = of_find_compatible_node(dev->of_node, NULL, "atmel,sama5d3-nfc"); + if (!nfc_np) { + dev_err(dev, "Could not find device node for sama5d3-nfc\n"); + return -ENODEV; + } nc->clk = of_clk_get(nfc_np, 0); if (IS_ERR(nc->clk)) { -- 2.7.4