From nobody Mon Feb 9 16:53:09 2026 Received: from azure-sdnproxy.icoremail.net (azure-sdnproxy.icoremail.net [207.46.229.174]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2D88067E78; Fri, 1 Mar 2024 07:03:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=207.46.229.174 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709276642; cv=none; b=cdeYmxyk8hA3YFCjei3vB07kcVHSSFIO6YXK7WOJImLexl9Xn1t/vjl3A7tSFuVkqopwC/t25OqiBrlC3d+Ngl+UVpmmXYNAmRC454wUAlkad+tcCK3kcUtV+XzZvUN760k9Emr4kpf27/44tN7nVkflt39ixfycpYH9RxfS2Cs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709276642; c=relaxed/simple; bh=n4GO0amLc6bIw/DDn5v7/jZicN+G4AVEDo5PV4Bf5ek=; h=From:To:Cc:Subject:Date:Message-Id; b=d1JI/pDCa/UG1eHE77g0Vhoujg78VXfY/89dgQ/gHyAx5ZdhNNmRiQFE7vVTmifPzj6iiUoOeyzQcIZJbeEvGGgtYyKNt7xG/AOU5yejzuCb7NZdsjRYBDOSeZJZ0aUFmhnNYGfJNypfbLrRDXAoAodrgKlo76Ofw/UG83DzBF4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=zju.edu.cn; spf=pass smtp.mailfrom=zju.edu.cn; arc=none smtp.client-ip=207.46.229.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=zju.edu.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zju.edu.cn Received: from ubuntu.localdomain (unknown [106.117.76.127]) by mail-app3 (Coremail) with SMTP id cC_KCgCHazXIfeFl6wq8AQ--.9024S2; Fri, 01 Mar 2024 15:03:46 +0800 (CST) From: Duoming Zhou To: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org, mturquette@baylibre.com, sboyd@kernel.org, michal.simek@amd.com, Duoming Zhou Subject: [PATCH v3] clk: zynq: Prevent null pointer dereference caused by kmalloc failure Date: Fri, 1 Mar 2024 15:03:36 +0800 Message-Id: <20240301070336.13700-1-duoming@zju.edu.cn> X-Mailer: git-send-email 2.17.1 X-CM-TRANSID: cC_KCgCHazXIfeFl6wq8AQ--.9024S2 X-Coremail-Antispam: 1UD129KBjvJXoW7urW7Jr43AF4Uuw48Wr43Awb_yoW8Aw4kpF WxWwn0yF4UXrWqgFn2kF18ZrySya17Wa42kw1rt3s7Z3Z8JFyUJFW5CF95Z3W8XrW8XFWa vF4qkr48W3WUAF7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUkl14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26F4U JVW0owA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oV Cq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0 I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r 4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwCY1x0262kKe7AKxVWU AVWUtwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14 v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkG c2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI 0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4U MIIF0xvEx4A2jsIEc7CjxVAFwI0_Jr0_GrUvcSsGvfC2KfnxnUUI43ZEXa7VUbSfO7UUUU U== X-CM-SenderInfo: qssqjiasttq6lmxovvfxof0/1tbiAwQHAWXg0lMJ0AANsR Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The kmalloc() in zynq_clk_setup() will return null if the physical memory has run out. As a result, if we use snprintf() to write data to the null address, the null pointer dereference bug will happen. This patch uses a stack variable to replace the kmalloc(). Fixes: 0ee52b157b8e ("clk: zynq: Add clock controller driver") Signed-off-by: Duoming Zhou --- Changes in v3: - Put stack variable in the head of the function and remove variable tmp. drivers/clk/zynq/clkc.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/clk/zynq/clkc.c b/drivers/clk/zynq/clkc.c index 7bdeaff2bfd..45479653c3b 100644 --- a/drivers/clk/zynq/clkc.c +++ b/drivers/clk/zynq/clkc.c @@ -215,7 +215,7 @@ static void __init zynq_clk_setup(struct device_node *n= p) int i; u32 tmp; int ret; - char *clk_name; + char clk_name[16]; unsigned int fclk_enable =3D 0; const char *clk_output_name[clk_max]; const char *cpu_parents[4]; @@ -426,12 +426,10 @@ static void __init zynq_clk_setup(struct device_node = *np) "gem1_emio_mux", CLK_SET_RATE_PARENT, SLCR_GEM1_CLK_CTRL, 0, 0, &gem1clk_lock); =20 - tmp =3D strlen("mio_clk_00x"); - clk_name =3D kmalloc(tmp, GFP_KERNEL); for (i =3D 0; i < NUM_MIO_PINS; i++) { int idx; =20 - snprintf(clk_name, tmp, "mio_clk_%2.2d", i); + snprintf(clk_name, 16, "mio_clk_%2.2d", i); idx =3D of_property_match_string(np, "clock-names", clk_name); if (idx >=3D 0) can_mio_mux_parents[i] =3D of_clk_get_parent_name(np, @@ -439,7 +437,6 @@ static void __init zynq_clk_setup(struct device_node *n= p) else can_mio_mux_parents[i] =3D dummy_nm; } - kfree(clk_name); clk_register_mux(NULL, "can_mux", periph_parents, 4, CLK_SET_RATE_NO_REPARENT, SLCR_CAN_CLK_CTRL, 4, 2, 0, &canclk_lock); --=20 2.17.1