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 1F370348C5A for ; Fri, 10 Jul 2026 14:38:58 +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=1783694340; cv=none; b=Iz+9vi5rOk7jY3neLVRiX0T5iavnR4PcTnWOjo2SQue4zIpw+9teqsAPyS5f4tsGvIOI0HqPzc+JE9GdYHNShBt4/9jmbSQmw3N02F6tWotta4osn7HOLk1a3emSTrez6JJpPsfJocrwPcGlABD3ScGDgPVbNW+s6cfe19O/8s0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783694340; c=relaxed/simple; bh=OkM6+rxKYutuPxBBB9XM/0xrzFcRCdD4ktOFJtiUc/E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AuKi7tJZYH+KbNcdQtD2/xWGdAeI4Rm37rpChcfKVoatC4b03CP3/I2kOsay7dl+oDXej7FZHIZD7Q3muwUmU+9BAeP8Gs55xCmj57Um0dzJcddz5lN76Y+3HVxRkbD9fYytYjaPkl8o57vrbtpa15sHB5/pYXxsL+LvKQLQCxE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YnWkHOIg; 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="YnWkHOIg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 49CF61F000E9; Fri, 10 Jul 2026 14:38:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783694338; bh=D0tMYkyUjS4cBSwZHMNSq8l4+rNcWd6J1RLbo1q+RxA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=YnWkHOIgEO5j9ztFYRrDA9mU5AcklaWanePTFyp87XGyyEDrP8gipeCGgX8uLkdiA fA3lFKoDKRYjhDar9fntTL68qzgj+0gdUjls7Zt4s9d1Mg7IKHa3j5gW4gF0LSXjSH dm7xPijEd9f9Dq3W8VF63PS/dlfh+DFze+9H/svn4G5UTeGcyKjc/TccXmA79EyuzB XHo3lSTBF9GaAohCquHa+FGcKVK5ah1veWn7RrnP8jdsp1xmJTccN+WDtfEtKHG/MU X7ocQQcB3DHx/vquaPuqGUV/T6NtXtfDQLlXxeud35zGm9A8lctuzg+Gm1+0KNEgUt hOm5OyhVnpLbw== From: Sasha Levin To: stable@vger.kernel.org Cc: "Rafael J. Wysocki" , Dave Jiang , Sasha Levin Subject: [PATCH 5.15.y] ACPI: NFIT: core: Fix acpi_nfit_init() error cleanup Date: Fri, 10 Jul 2026 10:38:56 -0400 Message-ID: <20260710143856.184042-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026070918-egotistic-sculptor-67ad@gregkh> References: <2026070918-egotistic-sculptor-67ad@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 | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index e420f773d67443..035384b919c1f7 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -3445,6 +3445,8 @@ 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) @@ -3669,7 +3671,10 @@ static void acpi_nfit_put_table(void *table) 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 @@ -3684,6 +3689,7 @@ 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 @@ -3751,13 +3757,14 @@ static int acpi_nfit_add(struct acpi_device *adev) sz - sizeof(struct acpi_table_nfit)); if (rc) - return rc; - return devm_add_action_or_reset(dev, acpi_nfit_shutdown, acpi_desc); + acpi_nfit_shutdown(acpi_desc); + + return rc; } static int acpi_nfit_remove(struct acpi_device *adev) { - /* see acpi_nfit_unregister */ + acpi_nfit_shutdown(dev_get_drvdata(&adev->dev)); return 0; } -- 2.53.0