From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from cstnet.cn (smtp81.cstnet.cn [159.226.251.81]) (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 77BBB149C7B for ; Mon, 22 Sep 2025 02:39:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.81 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758508753; cv=none; b=Qcz/epXrryfHmt9aeQ7GD023jpgShisvwtOxWJR+3lltS4Y65/5DiY7GZ8X/LqyxVl2SYSp3ZJqN913anuXAR9vlhooxAB5JtM0fJtyUsGNrBUPp57gqkGlDB6/ie4XyMNho5J7K6MeFwr9zZxBAKLJSStf7k0NRC/sSS3D646w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758508753; c=relaxed/simple; bh=2njLDJiojIEQxOF+htkPknhP0qErdIkYtULif4SAAOQ=; h=From:To:Cc:Subject:Date:Message-Id; b=ZK6ifqpXQ75/FO1aDBxfpu36R7r5pAKDGacL5wUSB2qamBxfq97k6hKj6q1+y1PiuaYlxg0DxXYOW2QdsO+LvPvoj4cn6qcsdVHYfO9QYGTYoRs4J8tMQIl9S/m4RFvhnaATsDpzgaOnNbbz+O6HzTgo4m4L2cbjbGrq++xjb0A= 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=159.226.251.81 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-03 (Coremail) with SMTP id rQCowAB3x4GpttBoZbgtBA--.19549S2; Mon, 22 Sep 2025 10:38:56 +0800 (CST) From: Ma Ke To: dpenkler@gmail.com, gregkh@linuxfoundation.org, matchstick@neverthere.org, dominik.karol.piatkowski@protonmail.com, arnd@arndb.de, nichen@iscas.ac.cn, paul.retourne@orange.fr Cc: linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, Ma Ke , stable@vger.kernel.org Subject: [PATCH] staging: gpib: Fix device reference leak in fmh_gpib driver Date: Mon, 22 Sep 2025 10:38:31 +0800 Message-Id: <20250922023831.21343-1-make24@iscas.ac.cn> X-Mailer: git-send-email 2.17.1 X-CM-TRANSID:rQCowAB3x4GpttBoZbgtBA--.19549S2 X-Coremail-Antispam: 1UD129KBjvJXoWxWF4fCr1UuF1kKrWkAF1UZFb_yoWrCF1Upa 17Xa1rKry0vrnaqF45Xr1UZFsayw4IyayYvw17C343Aa95Zry0ya1DW34ayryrAFykJr15 trW09r40gFWkZF7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPF14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26ryj6F1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26F4j 6r4UJwA2z4x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I8E87Iv6xkF7I0E14v26F 4UJVW0owAac4AC62xK8xCEY4vEwIxC4wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40E FcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr 0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8v x2IErcIFxwACI402YVCY1x02628vn2kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCY02Avz4 vE14v_Gr1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG 67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MI IYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E 14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJV W8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfUOTmh UUUUU X-CM-SenderInfo: ppdnvj2u6l2u1dvotugofq/ Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: The fmh_gpib driver contains a device reference count leak in fmh_gpib_attach_impl() where driver_find_device() increases the reference count of the device by get_device() when matching but this reference is not properly decreased. Add put_device() in fmh_gpib_attach_impl() and add put_device() in fmh_gpib_detach(), which ensures that the reference count of the device is correctly managed. Found by code review. Cc: stable@vger.kernel.org Fixes: 8e4841a0888c ("staging: gpib: Add Frank Mori Hess FPGA PCI GPIB driver") Signed-off-by: Ma Ke --- drivers/staging/gpib/fmh_gpib/fmh_gpib.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/drivers/staging/gpib/fmh_gpib/fmh_gpib.c b/drivers/staging/gpib/fmh_gpib/fmh_gpib.c index 4138f3d2bae7..245c8fe87eaa 100644 --- a/drivers/staging/gpib/fmh_gpib/fmh_gpib.c +++ b/drivers/staging/gpib/fmh_gpib/fmh_gpib.c @@ -1395,14 +1395,17 @@ static int fmh_gpib_attach_impl(struct gpib_board *board, const struct gpib_boar pdev = to_platform_device(board->dev); retval = fmh_gpib_generic_attach(board); - if (retval) + if (retval) { + put_device(board->dev); return retval; + } e_priv = board->private_data; nec_priv = &e_priv->nec7210_priv; res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "gpib_control_status"); if (!res) { + put_device(board->dev); dev_err(board->dev, "Unable to locate mmio resource\n"); return -ENODEV; } @@ -1410,6 +1413,7 @@ static int fmh_gpib_attach_impl(struct gpib_board *board, const struct gpib_boar if (request_mem_region(res->start, resource_size(res), pdev->name) == NULL) { + put_device(board->dev); dev_err(board->dev, "cannot claim registers\n"); return -ENXIO; } @@ -1418,6 +1422,7 @@ static int fmh_gpib_attach_impl(struct gpib_board *board, const struct gpib_boar nec_priv->mmiobase = ioremap(e_priv->gpib_iomem_res->start, resource_size(e_priv->gpib_iomem_res)); if (!nec_priv->mmiobase) { + put_device(board->dev); dev_err(board->dev, "Could not map I/O memory\n"); return -ENOMEM; } @@ -1426,12 +1431,14 @@ static int fmh_gpib_attach_impl(struct gpib_board *board, const struct gpib_boar res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dma_fifos"); if (!res) { + put_device(board->dev); dev_err(board->dev, "Unable to locate mmio resource for gpib dma port\n"); return -ENODEV; } if (request_mem_region(res->start, resource_size(res), pdev->name) == NULL) { + put_device(board->dev); dev_err(board->dev, "cannot claim registers\n"); return -ENXIO; } @@ -1439,6 +1446,7 @@ static int fmh_gpib_attach_impl(struct gpib_board *board, const struct gpib_boar e_priv->fifo_base = ioremap(e_priv->dma_port_res->start, resource_size(e_priv->dma_port_res)); if (!e_priv->fifo_base) { + put_device(board->dev); dev_err(board->dev, "Could not map I/O memory for fifos\n"); return -ENOMEM; } @@ -1447,10 +1455,14 @@ static int fmh_gpib_attach_impl(struct gpib_board *board, const struct gpib_boar (unsigned long)resource_size(e_priv->dma_port_res)); irq = platform_get_irq(pdev, 0); - if (irq < 0) + if (irq < 0) { + put_device(board->dev); return -EBUSY; + } + retval = request_irq(irq, fmh_gpib_interrupt, IRQF_SHARED, pdev->name, board); if (retval) { + put_device(board->dev); dev_err(board->dev, "cannot register interrupt handler err=%d\n", retval); @@ -1461,6 +1473,7 @@ static int fmh_gpib_attach_impl(struct gpib_board *board, const struct gpib_boar if (acquire_dma) { e_priv->dma_channel = dma_request_slave_channel(board->dev, "rxtx"); if (!e_priv->dma_channel) { + put_device(board->dev); dev_err(board->dev, "failed to acquire dma channel \"rxtx\".\n"); return -EIO; } @@ -1517,6 +1530,12 @@ void fmh_gpib_detach(struct gpib_board *board) resource_size(e_priv->gpib_iomem_res)); } fmh_gpib_generic_detach(board); + + if (board->dev) { + dev_set_drvdata(board->dev, NULL); + put_device(board->dev); + board->dev = NULL; + } } static int fmh_gpib_pci_attach_impl(struct gpib_board *board, -- 2.17.1