ARM: 9485/1: mm: acquire mmap write lock around show_pte() for user faultsgrafted

When CONFIG_DEBUG_USER=y, and cmdline "user_debug=31" is set,
a user fault may trigger show_pte() without any lock.
If another thread in the same process concurrently calls munmap(),
the page table pages may be freed while show_pte() is still traversing
them, causing a use-after-free in show_pte().

If CONFIG_ARM_LPAE=y, this may cause a kernel panic if the pages table
of PMD are freed when show_pte() is running.

Acquire mmap_write_lock() around show_pte() for user faults to fix the
contention.

For user faults, additionally restrict that show_pte() is called only
when the addr is a user-space address (addr < TASK_SIZE). This is because
the lock of tsk->mm only protects the virtual memory of user address space,
furthermore, dumping the page tables of a kernel-space address for user
faults is unnecessary and may have security implications.

Keep everything unchanged for kernel faults, because the kernel is
already in the "oops" state, acquiring a lock may risk a deadlock.

Co-developed-by: Qi Xi <xiqi2@huawei.com>

Fixes: 6d021b724481 ("ARM: dump pgd, pmd and pte states on unhandled data abort faults")
Link: https://lore.kernel.org/20260716014022.2823-1-xieyuanbin1@huawei.com
Acked-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Qi Xi <xiqi2@huawei.com>
Signed-off-by: Xie Yuanbin <xieyuanbin1@huawei.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

1 files changed, 229 insertions, 0 deletions

diff --git a/sound/soc/sof/control.c b/sound/soc/sof/control.c
new file mode 100644
index 000000000..74d997a4f
--- /dev/null
+++ b/sound/soc/sof/control.c
@@ -0,0 +1,229 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
+//
+// This file is provided under a dual BSD/GPLv2 license.  When using or
+// redistributing this file, you may do so under either license.
+//
+// Copyright(c) 2018 Intel Corporation
+//
+// Author: Liam Girdwood <liam.r.girdwood@linux.intel.com>
+//
+
+/* Mixer Controls */
+
+#include <linux/pm_runtime.h>
+#include <linux/leds.h>
+#include "sof-priv.h"
+#include "sof-audio.h"
+
+int snd_sof_volume_get(struct snd_kcontrol *kcontrol,
+		       struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_mixer_control *sm = (struct soc_mixer_control *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = sm->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->volume_get)
+		return tplg_ops->control->volume_get(scontrol, ucontrol);
+
+	return 0;
+}
+
+int snd_sof_volume_put(struct snd_kcontrol *kcontrol,
+		       struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_mixer_control *sm = (struct soc_mixer_control *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = sm->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->volume_put)
+		return tplg_ops->control->volume_put(scontrol, ucontrol);
+
+	return false;
+}
+
+int snd_sof_volume_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
+{
+	struct soc_mixer_control *sm = (struct soc_mixer_control *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = sm->dobj.private;
+	unsigned int channels = scontrol->num_channels;
+	int platform_max;
+
+	if (!sm->platform_max)
+		sm->platform_max = sm->max;
+	platform_max = sm->platform_max;
+
+	if (platform_max == 1 && !strstr(kcontrol->id.name, " Volume"))
+		uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
+	else
+		uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+
+	uinfo->count = channels;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = platform_max - sm->min;
+	return 0;
+}
+
+int snd_sof_switch_get(struct snd_kcontrol *kcontrol,
+		       struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_mixer_control *sm = (struct soc_mixer_control *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = sm->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->switch_get)
+		return tplg_ops->control->switch_get(scontrol, ucontrol);
+
+	return 0;
+}
+
+int snd_sof_switch_put(struct snd_kcontrol *kcontrol,
+		       struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_mixer_control *sm = (struct soc_mixer_control *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = sm->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->switch_put)
+		return tplg_ops->control->switch_put(scontrol, ucontrol);
+
+	return false;
+}
+
+int snd_sof_enum_get(struct snd_kcontrol *kcontrol,
+		     struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_enum *se = (struct soc_enum *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = se->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->enum_get)
+		return tplg_ops->control->enum_get(scontrol, ucontrol);
+
+	return 0;
+}
+
+int snd_sof_enum_put(struct snd_kcontrol *kcontrol,
+		     struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_enum *se = (struct soc_enum *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = se->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->enum_put)
+		return tplg_ops->control->enum_put(scontrol, ucontrol);
+
+	return false;
+}
+
+int snd_sof_bytes_get(struct snd_kcontrol *kcontrol,
+		      struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_bytes_ext *be = (struct soc_bytes_ext *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = be->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->bytes_get)
+		return tplg_ops->control->bytes_get(scontrol, ucontrol);
+
+	return 0;
+}
+
+int snd_sof_bytes_put(struct snd_kcontrol *kcontrol,
+		      struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_bytes_ext *be = (struct soc_bytes_ext *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = be->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->bytes_put)
+		return tplg_ops->control->bytes_put(scontrol, ucontrol);
+
+	return 0;
+}
+
+int snd_sof_bytes_ext_put(struct snd_kcontrol *kcontrol,
+			  const unsigned int __user *binary_data,
+			  unsigned int size)
+{
+	struct soc_bytes_ext *be = (struct soc_bytes_ext *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = be->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	/* make sure we have at least a header */
+	if (size < sizeof(struct snd_ctl_tlv))
+		return -EINVAL;
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->bytes_ext_put)
+		return tplg_ops->control->bytes_ext_put(scontrol, binary_data, size);
+
+	return 0;
+}
+
+int snd_sof_bytes_ext_volatile_get(struct snd_kcontrol *kcontrol, unsigned int __user *binary_data,
+				   unsigned int size)
+{
+	struct soc_bytes_ext *be = (struct soc_bytes_ext *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = be->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+	int ret, err;
+
+	/* ignore the ext_volatile_get call if the callbacks are not provided */
+	if (!tplg_ops || !tplg_ops->control ||
+	    !tplg_ops->control->bytes_ext_volatile_get)
+		return 0;
+
+	ret = pm_runtime_resume_and_get(scomp->dev);
+	if (ret < 0 && ret != -EACCES) {
+		dev_err_ratelimited(scomp->dev, "%s: failed to resume %d\n", __func__, ret);
+		return ret;
+	}
+
+	/* Make sure the DSP/firmware is booted up */
+	ret = snd_sof_boot_dsp_firmware(sdev);
+	if (!ret)
+		ret = tplg_ops->control->bytes_ext_volatile_get(scontrol,
+								binary_data,
+								size);
+
+	err = pm_runtime_put_autosuspend(scomp->dev);
+	if (err < 0)
+		dev_err_ratelimited(scomp->dev, "%s: failed to idle %d\n", __func__, err);
+
+	return ret;
+}
+
+int snd_sof_bytes_ext_get(struct snd_kcontrol *kcontrol,
+			  unsigned int __user *binary_data,
+			  unsigned int size)
+{
+	struct soc_bytes_ext *be = (struct soc_bytes_ext *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = be->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->bytes_ext_get)
+		return tplg_ops->control->bytes_ext_get(scontrol, binary_data, size);
+
+	return 0;
+}