[{"id":3675786,"web_url":"http://patchwork.ozlabs.org/comment/3675786/","msgid":"<37f2e32a-804d-7c59-d3d0-7148ef2cd95a@linux.intel.com>","list_archive_url":null,"date":"2026-04-10T10:18:43","subject":"Re: [PATCH 04/20] PCI/sysfs: Add CAP_SYS_ADMIN check to\n __resource_resize_store()","submitter":{"id":83553,"url":"http://patchwork.ozlabs.org/api/people/83553/","name":"Ilpo Järvinen","email":"ilpo.jarvinen@linux.intel.com"},"content":"On Fri, 10 Apr 2026, Krzysztof Wilczyński wrote:\n\n> Currently, the __resource_resize_store() allows writing to the\n> resourceN_resize sysfs attribute to change a BAR's size without\n> checking for capabilities, currently relying only on the file\n> access check.\n> \n> Resizing a BAR modifies PCI device configuration and can disrupt\n> active drivers. After the upcoming conversion to static attributes,\n> it will also trigger resource file updates via sysfs_update_groups().\n> \n> Thus, add a CAP_SYS_ADMIN check to prevent unprivileged users from\n> performing BAR resize operations.\n> \n> Signed-off-by: Krzysztof Wilczyński \n> ---\n> drivers/pci/pci-sysfs.c | 3 +++\n> 1 file changed, 3 insertions(+)\n> \n> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c\n> index ac4e7c516e78..6b8c8e62f68a 100644\n> --- a/drivers/pci/pci-sysfs.c\n> +++ b/drivers/pci/pci-sysfs.c\n> @@ -1619,6 +1619,9 @@ static ssize_t __resource_resize_store(struct device *dev, int n,\n> \tint ret;\n> \tu16 cmd;\n> \n> +\tif (!capable(CAP_SYS_ADMIN))\n> +\t\treturn -EPERM;\n> +\n> \tif (kstrtoul(buf, 0, &size) < 0)\n> \t\treturn -EINVAL;\n> \n> \n\nReviewed-by: Ilpo Järvinen ","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256\n header.s=Intel header.b=e9qftu5R;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=172.234.253.10; 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