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 5C5B230BF5C; Fri, 10 Apr 2026 05:50:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775800259; cv=none; b=XeZZ4uEKjnhngw5FDnwzqne9ubyv70UUC+9vbuDWxoVDDbiKOs/konKu3Cb/9gD3eAH3zeZ3+HxtUHLYE4Yuk+jSMs3yaKqPnAGWHqUSLPomqM4+jAQ8fla7gA74KHswaFqsLcjP4aIDx5e1AXUpVxufsfvJModdUrTTDwXHxKE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775800259; c=relaxed/simple; bh=SoGJBLsBAedU3UkQnFKz0LBvzv23roF9wHFr+0WZ14I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ehPQpaoDe7l0xuOG9AkQwoLApJIpbAyAvtwCg9R4Faxum2OSkv969fn142+4czwnRiFh2+gc30anilMu9+weaWU9wp1UlB460Uee4fxEAvRNPqu8X6aedHGAdtllYYlaVV78SKriiQ5RQvX/bZjsBGzdsENEspaPRAfbdBkIsSQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fFgo48Kh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fFgo48Kh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CFB7FC2BC9E; Fri, 10 Apr 2026 05:50:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775800259; bh=SoGJBLsBAedU3UkQnFKz0LBvzv23roF9wHFr+0WZ14I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fFgo48KhP2UwDP+v7nBAAQpFvOcYKzZLYUpNrDbkMijA1CB/EOL/wf0hnZlc+76nA QsgNEHBftINlrHeVEVCM5cfdhpaa2UA20qtkNr3ImV/HC/36UrrDrZu1vqo3Q8KvHH 8igsFPxntEMEia0YELY/E2uyNxICaOnxIC5jIi1ROZv8KDzNFgIncJy6+XVY/KlGVt hBUfxONpEMROdiKXuWSdcPvqOrOEmz5Tlvi5RZ7lP8ZW+WbtPwfj6HZ7o+ZSkR2k5I lKraDdD1mdbrwxowYEuiId6ylp90u/2drCdw7XYpIg3MuyfilzxfGOPlCH6FY0sPJl GaMDcCMe1ufsA== From: =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= To: Bjorn Helgaas Cc: Bjorn Helgaas , Manivannan Sadhasivam , Lorenzo Pieralisi , Magnus Lindholm , Matt Turner , Richard Henderson , Christophe Leroy , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Dexuan Cui , =?UTF-8?q?Krzysztof=20Ha=C5=82asa?= , Lukas Wunner , "Oliver O'Halloran" , Saurabh Singh Sengar , Shuan He , Srivatsa Bhat , =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= , linux-pci@vger.kernel.org, linux-alpha@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH 04/20] PCI/sysfs: Add CAP_SYS_ADMIN check to __resource_resize_store() Date: Fri, 10 Apr 2026 05:50:24 +0000 Message-ID: <20260410055040.39233-5-kwilczynski@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260410055040.39233-1-kwilczynski@kernel.org> References: <20260410055040.39233-1-kwilczynski@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, the __resource_resize_store() allows writing to the resourceN_resize sysfs attribute to change a BAR's size without checking for capabilities, currently relying only on the file access check. Resizing a BAR modifies PCI device configuration and can disrupt active drivers. After the upcoming conversion to static attributes, it will also trigger resource file updates via sysfs_update_groups(). Thus, add a CAP_SYS_ADMIN check to prevent unprivileged users from performing BAR resize operations. Signed-off-by: Krzysztof Wilczyński --- drivers/pci/pci-sysfs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index ac4e7c516e78..6b8c8e62f68a 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -1619,6 +1619,9 @@ static ssize_t __resource_resize_store(struct device *dev, int n, int ret; u16 cmd; + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + if (kstrtoul(buf, 0, &size) < 0) return -EINVAL; -- 2.53.0