From nobody Wed Oct 1 21:25:21 2025 Received: from cstnet.cn (smtp21.cstnet.cn [159.226.251.21]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9BEF954918; Sun, 28 Sep 2025 07:19:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.21 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759043998; cv=none; b=f4b1+HZ8GS3TMcyrdri8JLUaMBZMNiVrbNFLxEMJCJBKVJTnO7T/+LXCeYZUKNyMKeuw7+0anPadZT8NZcnSABiDWgu/u01d9BoMJhG52MmtcwvDVVnUV2bD0klOt1KdoonYNm4hnDRKOCRYxwmxTCWD9eYnicqCxNQ/i+CkESo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759043998; c=relaxed/simple; bh=rqiqW7XBpWmCWH9dwnSGTMOMnDvmv9oOluW8/IAQ5Ak=; h=From:To:Cc:Subject:Date:Message-Id; b=hvWR1sy7dqfvFVvloTRmDX0wRXzJIuN61L8Zq9nwO/HA1AuVcRpPmwTvmDx9vtf5QCiOWJPiRCSIcH/Uhgd3+a6foJVMiNOXLY5d9xVHmus+MSC0ZrTuqB+wMPKMZCVgFwP9frB5NJ+LDTqKN1ijfjo+E3zYWsVBlxXUcukxEGA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn; spf=pass smtp.mailfrom=iscas.ac.cn; arc=none smtp.client-ip=159.226.251.21 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iscas.ac.cn Received: from localhost.localdomain (unknown [202.112.113.212]) by APP-01 (Coremail) with SMTP id qwCowACnAKOH4dhoM2PtBw--.19109S2; Sun, 28 Sep 2025 15:19:48 +0800 (CST) From: Ma Ke To: syniurge@gmail.com, shyam-sundar.s-k@amd.com, andi.shyti@kernel.org, wsa@kernel.org Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, Ma Ke , stable@vger.kernel.org Subject: [PATCH v2] i2c: fix reference leak in MP2 PCI device Date: Sun, 28 Sep 2025 15:19:33 +0800 Message-Id: <20250928071933.1627-1-make24@iscas.ac.cn> X-Mailer: git-send-email 2.17.1 X-CM-TRANSID: qwCowACnAKOH4dhoM2PtBw--.19109S2 X-Coremail-Antispam: 1UD129KBjvJXoW7Zw17JF1rXr47XrWDGw4UJwb_yoW8Ww43pF W5JFWxAr95GF4vgw1DX3W8ZFy3Jw4vvw4rWrW7AwnY9F1rZas0kr97tF909w15ArWUAF4x tFW7tayruF1jqaDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9G14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r4j6ryUM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26F4j 6r4UJwA2z4x0Y4vEx4A2jsIE14v26F4UJVW0owA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1lnxkEFVAIw20F6cxK64vIFxWle2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xv F2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r 4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I 648v4I1lc7CjxVAaw2AFwI0_Jw0_GFylc2xSY4AK67AK6r4xMxAIw28IcxkI7VAKI48JMx C20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAF wI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20x vE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVWUJVW8JwCI42IY6xAIw20EY4v2 0xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxV W8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUbsmitUUUUU== X-CM-SenderInfo: ppdnvj2u6l2u1dvotugofq/ 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" In i2c_amd_probe(), amd_mp2_find_device() utilizes driver_find_next_device() which internally calls driver_find_device() to locate the matching device. driver_find_device() increments the reference count of the found device by calling get_device(), but amd_mp2_find_device() fails to call put_device() to decrement the reference count before returning. This results in a reference count leak of the PCI device each time i2c_amd_probe() is executed, which may prevent the device from being properly released and cause a memory leak. Found by code review. Cc: stable@vger.kernel.org Fixes: 529766e0a011 ("i2c: Add drivers for the AMD PCIe MP2 I2C controller") Signed-off-by: Ma Ke --- Changes in v2: - modified the missing initialization in the patch. Sorry for the omission. --- drivers/i2c/busses/i2c-amd-mp2-pci.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-amd-mp2-pci.c b/drivers/i2c/busses/i2c-= amd-mp2-pci.c index ef7370d3dbea..60edbabc2986 100644 --- a/drivers/i2c/busses/i2c-amd-mp2-pci.c +++ b/drivers/i2c/busses/i2c-amd-mp2-pci.c @@ -458,13 +458,16 @@ struct amd_mp2_dev *amd_mp2_find_device(void) { struct device *dev; struct pci_dev *pci_dev; + struct amd_mp2_dev *mp2_dev; =20 dev =3D driver_find_next_device(&amd_mp2_pci_driver.driver, NULL); if (!dev) return NULL; =20 pci_dev =3D to_pci_dev(dev); - return (struct amd_mp2_dev *)pci_get_drvdata(pci_dev); + mp2_dev =3D (struct amd_mp2_dev *)pci_get_drvdata(pci_dev); + put_device(dev); + return mp2_dev; } EXPORT_SYMBOL_GPL(amd_mp2_find_device); =20 --=20 2.17.1