From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5B1291C07 for ; Wed, 28 Dec 2022 16:19:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4454C433D2; Wed, 28 Dec 2022 16:18:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672244340; bh=IEHtdTtIRZLVgA0FAEWcFUoxODgJWkPXHc+W3Kknhhc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vUEomwBPNRptv+m6p/zY+9vA/wm19OLOmI9232ux7E1V/MyZCllmTsFnRW9qnH3Dk gDmAFvXRXv1p+wYphRZu3svis9uZDyUItjCle5nLrrapvw2PQEugltKdLBZ0VN1gTa out0IZ8R3ZC4bZdXlocxPuCVnSTTkY5n5c2EtDoE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Andrew Donnellan , Yang Yingliang , Sasha Levin Subject: [PATCH 6.0 0694/1073] ocxl: fix pci device refcount leak when calling get_function_0() Date: Wed, 28 Dec 2022 15:38:02 +0100 Message-Id: <20221228144346.882980778@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144328.162723588@linuxfoundation.org> References: <20221228144328.162723588@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Yang Yingliang [ Upstream commit 27158c72678b39ee01cc01de1aba6b51c71abe2f ] get_function_0() calls pci_get_domain_bus_and_slot(), as comment says, it returns a pci device with refcount increment, so after using it, pci_dev_put() needs be called. Get the device reference when get_function_0() is not called, so pci_dev_put() can be called in the error path and callers unconditionally. And add comment above get_dvsec_vendor0() to tell callers to call pci_dev_put(). Fixes: 87db7579ebd5 ("ocxl: control via sysfs whether the FPGA is reloaded on a link reset") Suggested-by: Andrew Donnellan Signed-off-by: Yang Yingliang Acked-by: Andrew Donnellan Link: https://lore.kernel.org/r/20221121154339.4088935-1-yangyingliang@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/misc/ocxl/config.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c index e401a51596b9..92ab49705f64 100644 --- a/drivers/misc/ocxl/config.c +++ b/drivers/misc/ocxl/config.c @@ -193,6 +193,18 @@ static int read_dvsec_vendor(struct pci_dev *dev) return 0; } +/** + * get_dvsec_vendor0() - Find a related PCI device (function 0) + * @dev: PCI device to match + * @dev0: The PCI device (function 0) found + * @out_pos: The position of PCI device (function 0) + * + * Returns 0 on success, negative on failure. + * + * NOTE: If it's successful, the reference of dev0 is increased, + * so after using it, the callers must call pci_dev_put() to give + * up the reference. + */ static int get_dvsec_vendor0(struct pci_dev *dev, struct pci_dev **dev0, int *out_pos) { @@ -202,10 +214,14 @@ static int get_dvsec_vendor0(struct pci_dev *dev, struct pci_dev **dev0, dev = get_function_0(dev); if (!dev) return -1; + } else { + dev = pci_dev_get(dev); } pos = find_dvsec(dev, OCXL_DVSEC_VENDOR_ID); - if (!pos) + if (!pos) { + pci_dev_put(dev); return -1; + } *dev0 = dev; *out_pos = pos; return 0; @@ -222,6 +238,7 @@ int ocxl_config_get_reset_reload(struct pci_dev *dev, int *val) pci_read_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD, &reset_reload); + pci_dev_put(dev0); *val = !!(reset_reload & BIT(0)); return 0; } @@ -243,6 +260,7 @@ int ocxl_config_set_reset_reload(struct pci_dev *dev, int val) reset_reload &= ~BIT(0); pci_write_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD, reset_reload); + pci_dev_put(dev0); return 0; } -- 2.35.1