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 49F67313E1B for ; Fri, 10 Jul 2026 13:32:37 +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=1783690359; cv=none; b=tSTqO8aFkqLcvD2W0G/PNM33VYKleeX+x41n7Suvmror0V9HEEzlIH95EuG20cUjhuWWWOP6g6MryT89FjlNb7LD9AsDsAKGUxsU71YIA+0ryZ0kNF89oav4bbIJyydD310UxFAsrMSvb2NqGgtrO0ADCmyrT7PvYjIiObqowCs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783690359; c=relaxed/simple; bh=Pzj3KLRrOnB+BZJJdaobgFPSgFN/oYJnjqO5Kc3uCm4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DRTc3nN8ZlZd2LVo67FWvFtrtwWzJBNL/FUF14SnjlB6NnFKDlDqgWR/3UBnJ6h1pV32JlLd8o3B5JNim5bC1UG92OZMO3ujueOoJEhwx6bVqxO1FflIYr6cb/5UHAvGK2iRipNEhyDn+sSl0Ypm18IUEtyS5QIScFm2Y1Xsdl4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=My0G3ZOT; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="My0G3ZOT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C73E61F00A3A; Fri, 10 Jul 2026 13:32:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783690357; bh=Po5sowEd2D40BtIqb0Dg9RezSmU/uI7W63PWfQNiqjM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=My0G3ZOTiKOzlAWJwgeiRVWtMK08hCMelfESM/xFaMhJpn39aRA7+Gd1rE9zqDO/T +rGYFyDLiD7cFTyafr46KsVmtKdTMK79lT9cGR91KNPMYxOeDAtcU7fjkNnzVH8U9W TtO7XAiHVgNnQAKK7ej6/nXza1WB0yZd9F9irIe9WgYXIMxJjpp0iarXELtxsdpHG8 U++bvs/2o59vRf4sOKXNuDQn1GHnxdr4m4HR7VDp8ljHeh2eUGf3f5B0NZwFmeEtQG XcPUsjfPsHBhDqnqvV48/FG9CHiCrmLZiKjvxj75PTQHrWyco30z641UKKFczQGvvJ KKUep6lIJYTvA== From: Sasha Levin To: stable@vger.kernel.org Cc: "Rafael J. Wysocki" , Dave Jiang , Sasha Levin Subject: [PATCH 6.18.y] ACPI: NFIT: core: Fix acpi_nfit_init() error cleanup Date: Fri, 10 Jul 2026 09:32:35 -0400 Message-ID: <20260710133235.81141-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026070915-atop-schematic-75ab@gregkh> References: <2026070915-atop-schematic-75ab@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Rafael J. Wysocki" [ Upstream commit 38bf27511ef41bffebd157ec3eba41fc89ba59cd ] If acpi_nfit_init() fails after adding the acpi_desc object to the acpi_descs list, that object is never removed from that list because the acpi_nfit_shutdown() devm action is not added for the NFIT device in that case. Next, the acpi_nfit_init() failure causes acpi_nfit_probe() to fail, the acpi_desc object is freed, and a dangling pointer is left behind in the acpi_descs. Any subsequent ACPI Machine Check Exception will trigger nfit_handle_mce() which iterates over acpi_descs and so a use-after-free will occur. Moreover, if acpi_nfit_probe() returns 0 after installing a notify handler for the NFIT device and without allocating the acpi_desc object and setting the NFIT device's driver data pointer, the acpi_desc object will be allocated by acpi_nfit_update_notify() and acpi_nfit_init() will be called to initialize it. Regardless of whether or not acpi_nfit_init() fails in that case, the acpi_nfit_shutdown() devm action is not added for the NFIT device and acpi_desc is never removed from the acpi_descs list. If the acpi_desc object is freed subsequently on driver removal, any subsequent ACPI MCE will lead to a use-after-free like in the previous case. To address the first issue mentioned above, make acpi_nfit_probe() call acpi_nfit_shutdown() directly on acpi_nfit_init() failures and to address the other one, add a remove callback to the driver and make it call acpi_nfit_shutdown(). Also, since it is now possible to pass NULL to acpi_nfit_shutdown() or the acpi_desc object passed to it may not have been initialized, add checks against NULL for acpi_desc and its nvdimm_bus field to that function and make acpi_nfit_unregister() clear the latter after unregistering the NVDIMM bus. Fixes: a61fe6f7902e ("nfit, tools/testing/nvdimm: unify common init for acpi_nfit_desc") Fixes: fbabd829fe76 ("acpi, nfit: fix module unload vs workqueue shutdown race") Signed-off-by: Rafael J. Wysocki Cc: All applicable Reviewed-by: Dave Jiang Link: https://patch.msgid.link/1963615.tdWV9SEqCh@rafael.j.wysocki Signed-off-by: Sasha Levin --- drivers/acpi/nfit/core.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 3eb56b77cb6d93..30b5d30bbd44a1 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -3061,6 +3061,8 @@ static void acpi_nfit_unregister(void *data) struct acpi_nfit_desc *acpi_desc = data; nvdimm_bus_unregister(acpi_desc->nvdimm_bus); + /* The nvdimm_bus object may have been freed, so clear the pointer. */ + acpi_desc->nvdimm_bus = NULL; } int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, void *data, acpi_size sz) @@ -3301,7 +3303,10 @@ static void acpi_nfit_remove_notify_handler(void *data) void acpi_nfit_shutdown(void *data) { struct acpi_nfit_desc *acpi_desc = data; - struct device *bus_dev = to_nvdimm_bus_dev(acpi_desc->nvdimm_bus); + struct device *bus_dev; + + if (!acpi_desc || !acpi_desc->nvdimm_bus) + return; /* * Destruct under acpi_desc_lock so that nfit_handle_mce does not @@ -3316,6 +3321,7 @@ void acpi_nfit_shutdown(void *data) mutex_unlock(&acpi_desc->init_mutex); cancel_delayed_work_sync(&acpi_desc->dwork); + bus_dev = to_nvdimm_bus_dev(acpi_desc->nvdimm_bus); /* * Bounce the nvdimm bus lock to make sure any in-flight * acpi_nfit_ars_rescan() submissions have had a chance to @@ -3393,9 +3399,14 @@ static int acpi_nfit_add(struct acpi_device *adev) sz - sizeof(struct acpi_table_nfit)); if (rc) - return rc; + acpi_nfit_shutdown(acpi_desc); - return devm_add_action_or_reset(dev, acpi_nfit_shutdown, acpi_desc); + return rc; +} + +static void acpi_nfit_remove(struct acpi_device *adev) +{ + acpi_nfit_shutdown(dev_get_drvdata(&adev->dev)); } static void acpi_nfit_update_notify(struct device *dev, acpi_handle handle) @@ -3479,6 +3490,7 @@ static struct acpi_driver acpi_nfit_driver = { .ids = acpi_nfit_ids, .ops = { .add = acpi_nfit_add, + .remove = acpi_nfit_remove, }, }; -- 2.53.0