From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794060564; b=JIKroR7KPMbQbKecuguF0XCYqAk36/yeEZt8naaMim7xVrf27YcEe/OMfDhQAAYG9pRa EqqEV5PvgBVe0ry7r9UGApOKNG9HDh78xGv3cikUK1Nazr11K7NTtE1VVWt3ZISH807Xy tFZ2XfkRD4HYF1naeWQ6tpy5NznRqEK9qBUUPFfyOGk0BfJK7oThFytHNwp/w8Bns8S/G NNyvKuTVd0AHbmwjMa4sKspmy8RGp5LeTdhH88y0QypNwGQeW4VdV4eCRwi2vmoLeplKI Swgv7o8yAAimA+SGBmdmTTkK84DsAh9m1gPfwKQS8eIv58xsAcOyMxVbKCWZU5iz91w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794060564; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=yuFVQ944ey6ZSzQzZCm9gAf/qYQk6ts33E7xhCu12kk=; b=GotTqifuiyuVqGyy0TzsrG/3KKEh5Pd6wMwwF4FfGCYPsTOetJvWDeV5lm2/Ma5zbuYl NISdEHRqRNwtZsDzKG9GXdnmnXEjFqiRg9HvY1TjwFW5tCqr+QDEYyXiOUwyDEKubdhbw 9wkq42KiU5r9gVaSb4fcDS9eDItAih61j7VwQIE4PaJEH2q6JtvojUG7raXJV3AM361O2 DAHDrhi5ElTN1zPDxritWw5mYR4TE2l6+GKJ44W80u2xXUDK2glmI848ppLFUbNNvJYQB w1vNScjyJiqJkM2xuqENVqyx7bIuOr2/kQc+gXQCUdKthTpCw1+83gpJfXSDAWHXkqA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="BTRTV/CB"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 13232606A326; Sat, 7 Nov 2026 14:09:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=BTRTV/CB Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD4261F0089F; Sat, 7 Nov 2026 14:09:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794060563; bh=yuFVQ944ey6ZSzQzZCm9gAf/qYQk6ts33E7xhCu12kk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BTRTV/CBwk81o2POiuBAkuWbqobeQrM90tXnKMAZCT0Eg/7SmIHyGujDsJu2x+308 8wpGhevGvU6uqnsa6FhAKFq21Vy/8hYi30PSKl3T4TSaG+PVJcQTWVo8z2vYgYnEFM dNUPEJhYPuctrsFJ7+h8yl2vxU1lMSP+qgV86YqM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Asad Kamal , Lijo Lazar , Alex Deucher , Sasha Levin Subject: [PATCH 6.12 0026/1536] drm/amdgpu: Gate debugfs MMIO access on kernel lockdown Date: Sat, 7 Nov 2026 08:34:02 -0500 Message-ID: <20261107134958.411985828@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134957.653319350@linuxfoundation.org> References: <20261107134957.653319350@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Asad Kamal [ Upstream commit 17ac73b24006700f50972d37e297dec1f523c14a ] amdgpu_regs, amdgpu_regs2, and related debugfs nodes allow arbitrary MMIO read/write via RREG32/WREG32 without checking security_locked_down(). On kernel_lockdown=integrity systems this bypasses the same restrictions as /dev/mem and PCI config space sysfs. Check LOCKDOWN_PCI_ACCESS (matching pci-sysfs) at the entry of every debugfs handler that performs direct register access. v2: Use consistent check as per previous check to use LOCKDOWN_DEBUGFS(Lijo) v3: Do not create any entry from amdgpu_debugfs_regs_init() if LOCKDOWN_PCI_ACCESS is active and log once. (Lijo) Signed-off-by: Asad Kamal Reviewed-by: Lijo Lazar Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c index aab7b75ebc3fe..3e4a6c13bb7b7 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include "amdgpu.h" @@ -1646,6 +1647,12 @@ int amdgpu_debugfs_regs_init(struct amdgpu_device *adev) struct dentry *ent, *root = minor->debugfs_root; unsigned int i; + if (security_locked_down(LOCKDOWN_PCI_ACCESS)) { + drm_info(adev_to_drm(adev), + "amdgpu: HW debugfs nodes disabled (kernel lockdown)\n"); + return 0; + } + for (i = 0; i < ARRAY_SIZE(debugfs_regs); i++) { ent = debugfs_create_file(debugfs_regs_names[i], S_IFREG | 0400, root, -- 2.53.0