From nobody Tue Jun 30 05:36:08 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C882C433F5 for ; Mon, 24 Jan 2022 16:52:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243950AbiAXQwW (ORCPT ); Mon, 24 Jan 2022 11:52:22 -0500 Received: from mta-p7.oit.umn.edu ([134.84.196.207]:40470 "EHLO mta-p7.oit.umn.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241220AbiAXQwO (ORCPT ); Mon, 24 Jan 2022 11:52:14 -0500 Received: from localhost (unknown [127.0.0.1]) by mta-p7.oit.umn.edu (Postfix) with ESMTP id 4JjGHK41lQz9w2xr for ; Mon, 24 Jan 2022 16:52:13 +0000 (UTC) X-Virus-Scanned: amavisd-new at umn.edu Received: from mta-p7.oit.umn.edu ([127.0.0.1]) by localhost (mta-p7.oit.umn.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id dyiY9F1KNFCt for ; Mon, 24 Jan 2022 10:52:13 -0600 (CST) Received: from mail-pf1-f199.google.com (mail-pf1-f199.google.com [209.85.210.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mta-p7.oit.umn.edu (Postfix) with ESMTPS id 4JjGHK20Z8z9w2xw for ; Mon, 24 Jan 2022 10:52:13 -0600 (CST) DMARC-Filter: OpenDMARC Filter v1.3.2 mta-p7.oit.umn.edu 4JjGHK20Z8z9w2xw DKIM-Filter: OpenDKIM Filter v2.11.0 mta-p7.oit.umn.edu 4JjGHK20Z8z9w2xw Received: by mail-pf1-f199.google.com with SMTP id i6-20020a626d06000000b004c0abfd53b3so9515583pfc.12 for ; Mon, 24 Jan 2022 08:52:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=umn.edu; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Y+tHqbGxYTZxLAsM/2xshYqCJwWoXL4A34qQepi4q+A=; b=qTRfymmBKC6ulS4TRgxgZKClqn/zZAFzLlGZ9X8q4tPcpU4l6boeMZwpKIVwgfGf0u BUzjWVHswyFWdKCrVRUgyIiUUSdCxNlyQoD40ujFs9DLvHyZ5IA7opMGjYe5NQ32dJ4s jBHYtVUZJ9tooDz2GRD3vJjJ9KXzADNLTsZnWMHV1/uH9g5OquNsWbgWgABBZOfvcIMI efVYuFAs1lQ5EQjCC6JHzf974Lvb+FSKV438Tb5OlBqBm53q1eP38MqODlR1/CsMItMD rk93yz9f+XgCR0cth3LHoR1OsHnZy9nQfUNAJKrIPSj44Y2ihnIQvZAZOLi73L3bI4wh lTvQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Y+tHqbGxYTZxLAsM/2xshYqCJwWoXL4A34qQepi4q+A=; b=dcpwTNFSSVEwfI8QAt9qN+4eygHdiSJAn9uFRJPW+Mxd48KX7fKGv+/N29STmMEHAH neAYpjm1Knp2M9iUNPvIQzCQJWiIlfv0Nvw/XV+i9SAp03KmMhDhwIrAeJe3qhlU3SX5 9rMKx2+05dmmSM9jceS83vkLgcZDgfzsshUK8SNBOx4yI4EzomTU7oSLVrL6pl5IafuH wUf8QqVeHOeXo3GMTmEQSTXCjzQKELoMLbR+nj1nT9f8QBmFnsptHgZMziPMYIjhOKsp TdTk03yz0WTb2NGzOw0/U/w5Hvd30HpUbcn8EKziAZrX23JMJ+YGVDQ+yVXKOLK0rBFB JVhw== X-Gm-Message-State: AOAM533cCaw78HmcSTq3Z7M28nYuKdC4DowWQMfrZT277SZpd2Om81Ei MmCH5cKr2p8Ig2S8dW4nLhs9GgptRAVU4PptAlDngDlx5k8TSvFgygx2femhDzE1kfTHHfgnJ3i 7SfxJXV/7cxq1HAI6C3EXmZNt5Wpj X-Received: by 2002:a17:90a:9488:: with SMTP id s8mr2752325pjo.40.1643043132426; Mon, 24 Jan 2022 08:52:12 -0800 (PST) X-Google-Smtp-Source: ABdhPJx4GMuF2+Hhif3WBk5US0gETu4RE21+7UtomtMNIIf3WFvwybUV3W7ojOWWWG8Hp0/sZjoQAA== X-Received: by 2002:a17:90a:9488:: with SMTP id s8mr2752309pjo.40.1643043132222; Mon, 24 Jan 2022 08:52:12 -0800 (PST) Received: from zqy787-GE5S.lan ([36.4.61.248]) by smtp.gmail.com with ESMTPSA id 17sm16984414pfl.175.2022.01.24.08.52.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Jan 2022 08:52:11 -0800 (PST) From: Zhou Qingyang To: zhou1615@umn.edu Cc: kjlu@umn.edu, Abel Vesa , Michael Turquette , Stephen Boyd , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Adam Ford , linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH] clk: imx: Fix a NULL pointer dereference in imx_register_uart_clocks() Date: Tue, 25 Jan 2022 00:52:06 +0800 Message-Id: <20220124165206.55059-1-zhou1615@umn.edu> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" In imx_register_uart_clocks(), the global variable imx_uart_clocks is assigned by kcalloc() and there is a dereference of in the next for loop, which could introduce a NULL pointer dereference on failure of kcalloc(). Fix this by adding a NULL check of imx_uart_clocks. This bug was found by a static analyzer. Builds with 'make allyesconfig' show no new warnings, and our static analyzer no longer warns about this code. Fixes: 379c9a24cc23 ("clk: imx: Fix reparenting of UARTs not associated wit= h stdout") Signed-off-by: Zhou Qingyang --- The analysis employs differential checking to identify inconsistent=20 security operations (e.g., checks or kfrees) between two code paths=20 and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs.=20 Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. drivers/clk/imx/clk.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/clk/imx/clk.c b/drivers/clk/imx/clk.c index 7cc669934253..99249ab361d2 100644 --- a/drivers/clk/imx/clk.c +++ b/drivers/clk/imx/clk.c @@ -173,6 +173,8 @@ void imx_register_uart_clocks(unsigned int clk_count) int i; =20 imx_uart_clocks =3D kcalloc(clk_count, sizeof(struct clk *), GFP_KERNEL); + if (!imx_uart_clocks) + return; =20 if (!of_stdout) return; --=20 2.25.1