From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 C8CB9353EF7; Sat, 12 Sep 2026 10:10:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789207836; cv=none; b=g7YkTEe4lm2B5Q0EQ9Aue7QNCcM9Yp78JAFb59akhwToQ2gR5cr+JRk/HAfJq2zRX4jboRXzTkUUf+iV9jA5YX6aON7rzHIuIhSDDIkAp/lv6ikrIb5E+sgepewW0mOe99k00eYU8c1FASIF2aeruj9mmSA77zjPrUTVdCO5E2E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789207836; c=relaxed/simple; bh=p4l7MAMjDvtdHNzyXV14vxgiX/mJO9RPWs5xb6v6JW4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Q19Gs9qjUBMVw8ugFvhIiz1dZXR2jRzoVe53v9Yr/wsZTeDvKN7rV4Z6m8RTWYJjXJUb03PXd8DidpoM7DHL1hIa/VYUMyAgNUjT6nmg7PxILR99XKxN+NpEORLQ9QMZ77dRJOb9AtaheSF9YHVX8XCRv+YvSPKnkSdXPr6ssbA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=jnzn89g4; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="jnzn89g4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 823AD1F000FF; Sat, 12 Sep 2026 10:10:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789207834; bh=KrlNd0mv6JLLp28mDnE2wn72BWZo9uFodX7+nhRIVKQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jnzn89g41oaK/bYbEe9N2/jMRyz+HctCLgZFxv/VmFmAeyyjIOASbKDko3ANQsWYn +eGiMfIh71sap1sqEJfjRjQHfsYJ0nIaogW5uYrtHczK1Zp0M/gbXuvIW7So+esrkV 5AcQxXgO83ieUKjwV2CNgGzx0n5YZtPkToN9qAaY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sashiko AI review , Chen Pei , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 6.18 0493/1518] ACPI: PCI: Clear driver_data on all paths that free the acpi_pci_root Date: Sat, 12 Sep 2026 08:44:22 +0200 Message-ID: <20260912065634.597777499@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065623.398859879@linuxfoundation.org> References: <20260912065623.398859879@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chen Pei [ Upstream commit 8a742141f7ab84975aa758b775567ef4740ef0cf ] acpi_pci_root_add() assigns the freshly allocated root to device->driver_data before dmar_device_add() and pci_acpi_scan_root(). Both failure paths reach the end: label where root is kfree()'d, but only the pci_acpi_scan_root() path clears driver_data first. When dmar_device_add() fails during a hot-add, root is freed while device->driver_data still points at it. The ACPI core does not clear driver_data on attach failure, so a later acpi_pci_find_root() call may dereference this dangling pointer. acpi_pci_root_remove() has the same problem: it frees root without clearing device->driver_data, leaving a dangling pointer behind after the root bridge is removed. Move the NULL assignment to the shared end: label so every error path in acpi_pci_root_add() clears driver_data before freeing root, and clear it in acpi_pci_root_remove() as well, so the object is never left reachable through driver_data after being freed. Fixes: db89b4f0dbab ("ACPI: catch calls of acpi_driver_data on pointer of wrong type") Reported-by: Sashiko AI review Link: https://sashiko.dev/#/patchset/20260526025118.38935-1-cp0613@linux.alibaba.com Link: https://sashiko.dev/#/patchset/20260707121258.11640-1-cp0613@linux.alibaba.com Signed-off-by: Chen Pei Link: https://patch.msgid.link/20260715135048.3278-1-cp0613@linux.alibaba.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/acpi/pci_root.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 74ade41603145..32b868bd8487b 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -730,7 +730,6 @@ static int acpi_pci_root_add(struct acpi_device *device, dev_err(&device->dev, "Bus %04x:%02x not present in PCI namespace\n", root->segment, (unsigned int)root->secondary.start); - device->driver_data = NULL; result = -ENODEV; goto remove_dmar; } @@ -766,6 +765,7 @@ static int acpi_pci_root_add(struct acpi_device *device, if (hotadd) dmar_device_remove(handle); end: + device->driver_data = NULL; kfree(root); return result; } @@ -789,6 +789,7 @@ static void acpi_pci_root_remove(struct acpi_device *device) pci_unlock_rescan_remove(); + device->driver_data = NULL; kfree(root); } -- 2.53.0