x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.

The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:

<__hrtimer_run_queues+249>:  nopl   0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>:  mov    %r14,%rdi
<__hrtimer_run_queues+257>:  cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>:  mov    %eax,%r12d
<__hrtimer_run_queues+266>:  xchg   %ax,%ax
<__hrtimer_run_queues+268>:  mov    %r13,%rdi

Which triggers this crash:

  BUG: unable to handle page fault for address: 00000000000f41c9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
  RIP: 0010:__hrtimer_run_queues+0x106/0x230

Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.

The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.

During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.

Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.

[ mingo: Refined the changelog ]

Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 396 insertions, 0 deletions

diff --git a/sound/soc/codecs/hda.c b/sound/soc/codecs/hda.c
new file mode 100644
index 000000000..237b0b060
--- /dev/null
+++ b/sound/soc/codecs/hda.c
@@ -0,0 +1,396 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright(c) 2021-2022 Intel Corporation
+//
+// Author: Cezary Rojewski <cezary.rojewski@intel.com>
+//
+
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <sound/soc.h>
+#include <sound/hdaudio_ext.h>
+#include <sound/hda_i915.h>
+#include <sound/hda_codec.h>
+#include "hda.h"
+
+static int hda_codec_create_dais(struct hda_codec *codec, int pcm_count,
+				 struct snd_soc_dai_driver **drivers)
+{
+	struct device *dev = &codec->core.dev;
+	struct snd_soc_dai_driver *drvs;
+	struct hda_pcm *pcm;
+	int i;
+
+	drvs = devm_kcalloc(dev, pcm_count, sizeof(*drvs), GFP_KERNEL);
+	if (!drvs)
+		return -ENOMEM;
+
+	pcm = list_first_entry(&codec->pcm_list_head, struct hda_pcm, list);
+
+	for (i = 0; i < pcm_count; i++, pcm = list_next_entry(pcm, list)) {
+		struct snd_soc_pcm_stream *stream;
+		int dir;
+
+		dev_info(dev, "creating for %s %d\n", pcm->name, i);
+		drvs[i].id = i;
+		drvs[i].name = pcm->name;
+		drvs[i].ops = &snd_soc_hda_codec_dai_ops;
+
+		dir = SNDRV_PCM_STREAM_PLAYBACK;
+		stream = &drvs[i].playback;
+		if (!pcm->stream[dir].substreams) {
+			dev_info(dev, "skipping playback dai for %s\n", pcm->name);
+			goto capture_dais;
+		}
+
+		stream->stream_name =
+			devm_kasprintf(dev, GFP_KERNEL, "%s %s", pcm->name,
+				       snd_pcm_direction_name(dir));
+		if (!stream->stream_name)
+			return -ENOMEM;
+		stream->channels_min = pcm->stream[dir].channels_min;
+		stream->channels_max = pcm->stream[dir].channels_max;
+		stream->rates = pcm->stream[dir].rates;
+		stream->formats = pcm->stream[dir].formats;
+		stream->subformats = pcm->stream[dir].subformats;
+		stream->sig_bits = pcm->stream[dir].maxbps;
+
+capture_dais:
+		dir = SNDRV_PCM_STREAM_CAPTURE;
+		stream = &drvs[i].capture;
+		if (!pcm->stream[dir].substreams) {
+			dev_info(dev, "skipping capture dai for %s\n", pcm->name);
+			continue;
+		}
+
+		stream->stream_name =
+			devm_kasprintf(dev, GFP_KERNEL, "%s %s", pcm->name,
+				       snd_pcm_direction_name(dir));
+		if (!stream->stream_name)
+			return -ENOMEM;
+		stream->channels_min = pcm->stream[dir].channels_min;
+		stream->channels_max = pcm->stream[dir].channels_max;
+		stream->rates = pcm->stream[dir].rates;
+		stream->formats = pcm->stream[dir].formats;
+		stream->subformats = pcm->stream[dir].subformats;
+		stream->sig_bits = pcm->stream[dir].maxbps;
+	}
+
+	*drivers = drvs;
+	return 0;
+}
+
+static int hda_codec_register_dais(struct hda_codec *codec, struct snd_soc_component *component)
+{
+	struct snd_soc_dai_driver *drvs = NULL;
+	struct snd_soc_dapm_context *dapm;
+	struct hda_pcm *pcm;
+	int ret, pcm_count = 0;
+
+	if (list_empty(&codec->pcm_list_head))
+		return -EINVAL;
+	list_for_each_entry(pcm, &codec->pcm_list_head, list)
+		pcm_count++;
+
+	ret = hda_codec_create_dais(codec, pcm_count, &drvs);
+	if (ret < 0)
+		return ret;
+
+	dapm = snd_soc_component_to_dapm(component);
+
+	list_for_each_entry(pcm, &codec->pcm_list_head, list) {
+		struct snd_soc_dai *dai;
+
+		dai = snd_soc_register_dai(component, drvs, false);
+		if (!dai) {
+			dev_err(component->dev, "register dai for %s failed\n", pcm->name);
+			return -EINVAL;
+		}
+
+		ret = snd_soc_dapm_new_dai_widgets(dapm, dai);
+		if (ret < 0) {
+			dev_err(component->dev, "create widgets failed: %d\n", ret);
+			snd_soc_unregister_dai(dai);
+			return ret;
+		}
+
+		snd_soc_dai_init_dma_data(dai, &pcm->stream[0], &pcm->stream[1]);
+		drvs++;
+	}
+
+	return 0;
+}
+
+static void hda_codec_unregister_dais(struct hda_codec *codec,
+				      struct snd_soc_component *component)
+{
+	struct snd_soc_dai *dai, *save;
+	struct hda_pcm *pcm;
+
+	for_each_component_dais_safe(component, dai, save) {
+		int stream;
+
+		list_for_each_entry(pcm, &codec->pcm_list_head, list) {
+			if (strcmp(dai->driver->name, pcm->name))
+				continue;
+
+			for_each_pcm_streams(stream)
+				snd_soc_dapm_free_widget(snd_soc_dai_get_widget(dai, stream));
+
+			snd_soc_unregister_dai(dai);
+			break;
+		}
+	}
+}
+
+int hda_codec_probe_complete(struct hda_codec *codec)
+{
+	struct hdac_device *hdev = &codec->core;
+	struct hdac_bus *bus = hdev->bus;
+	int ret;
+
+	ret = snd_hda_codec_build_controls(codec);
+	if (ret < 0) {
+		dev_err(&hdev->dev, "unable to create controls %d\n", ret);
+		return ret;
+	}
+
+	/* Bus suspended codecs as it does not manage their pm */
+	pm_runtime_set_active(&hdev->dev);
+	/* rpm was forbidden in snd_hda_codec_device_new() */
+	snd_hda_codec_set_power_save(codec, 2000);
+	snd_hda_codec_register(codec);
+
+	/* Complement pm_runtime_get_sync(bus) in probe */
+	pm_runtime_put_autosuspend(bus->dev);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hda_codec_probe_complete);
+
+/* Expects codec with usage_count=1 and status=suspended */
+static int hda_codec_probe(struct snd_soc_component *component)
+{
+	struct hda_codec *codec = dev_to_hda_codec(component->dev);
+	struct hda_codec_driver *driver = hda_codec_to_driver(codec);
+	struct hdac_device *hdev = &codec->core;
+	struct hdac_bus *bus = hdev->bus;
+	struct hdac_ext_link *hlink;
+	int ret;
+
+#ifdef CONFIG_PM
+	WARN_ON(atomic_read(&hdev->dev.power.usage_count) != 1 ||
+		!pm_runtime_status_suspended(&hdev->dev));
+#endif
+
+	hlink = snd_hdac_ext_bus_get_hlink_by_addr(bus, hdev->addr);
+	if (!hlink) {
+		dev_err(&hdev->dev, "hdac link not found\n");
+		return -EIO;
+	}
+
+	pm_runtime_get_sync(bus->dev);
+	if (hda_codec_is_display(codec))
+		snd_hdac_display_power(bus, hdev->addr, true);
+	snd_hdac_ext_bus_link_get(bus, hlink);
+
+	ret = snd_hda_codec_device_new(codec->bus, component->card->snd_card, hdev->addr, codec,
+				       false);
+	if (ret < 0) {
+		dev_err(&hdev->dev, "codec create failed: %d\n", ret);
+		goto device_new_err;
+	}
+
+	ret = snd_hda_codec_set_name(codec, codec->preset->name);
+	if (ret < 0) {
+		dev_err(&hdev->dev, "set name: %s failed: %d\n", codec->preset->name, ret);
+		goto err;
+	}
+
+	ret = snd_hdac_regmap_init(&codec->core);
+	if (ret < 0) {
+		dev_err(&hdev->dev, "regmap init failed: %d\n", ret);
+		goto err;
+	}
+
+	if (WARN_ON(!(driver->ops && driver->ops->probe))) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	ret = driver->ops->probe(codec, codec->preset);
+	if (ret < 0) {
+		dev_err(&hdev->dev, "codec init failed: %d\n", ret);
+		goto err;
+	}
+
+	ret = snd_hda_codec_parse_pcms(codec);
+	if (ret < 0) {
+		dev_err(&hdev->dev, "unable to map pcms to dai: %d\n", ret);
+		goto parse_pcms_err;
+	}
+
+	ret = hda_codec_register_dais(codec, component);
+	if (ret < 0) {
+		dev_err(&hdev->dev, "update dais failed: %d\n", ret);
+		goto parse_pcms_err;
+	}
+
+	if (!hda_codec_is_display(codec)) {
+		ret = hda_codec_probe_complete(codec);
+		if (ret < 0)
+			goto complete_err;
+	}
+
+	codec->core.lazy_cache = true;
+
+	return 0;
+
+complete_err:
+	hda_codec_unregister_dais(codec, component);
+parse_pcms_err:
+	if (driver->ops->remove)
+		driver->ops->remove(codec);
+err:
+	snd_hda_codec_cleanup_for_unbind(codec);
+device_new_err:
+	if (hda_codec_is_display(codec))
+		snd_hdac_display_power(bus, hdev->addr, false);
+
+	snd_hdac_ext_bus_link_put(bus, hlink);
+
+	pm_runtime_put_autosuspend(bus->dev);
+	return ret;
+}
+
+/* Leaves codec with usage_count=1 and status=suspended */
+static void hda_codec_remove(struct snd_soc_component *component)
+{
+	struct hda_codec *codec = dev_to_hda_codec(component->dev);
+	struct hda_codec_driver *driver = hda_codec_to_driver(codec);
+	struct hdac_device *hdev = &codec->core;
+	struct hdac_bus *bus = hdev->bus;
+	struct hdac_ext_link *hlink;
+	bool was_registered = codec->core.registered;
+
+	/* Don't allow any more runtime suspends */
+	pm_runtime_forbid(&hdev->dev);
+
+	hda_codec_unregister_dais(codec, component);
+
+	if (driver->ops->remove)
+		driver->ops->remove(codec);
+
+	snd_hda_codec_cleanup_for_unbind(codec);
+	pm_runtime_put_noidle(&hdev->dev);
+	/* snd_hdac_device_exit() is only called on bus remove */
+	pm_runtime_set_suspended(&hdev->dev);
+
+	if (hda_codec_is_display(codec))
+		snd_hdac_display_power(bus, hdev->addr, false);
+
+	hlink = snd_hdac_ext_bus_get_hlink_by_addr(bus, hdev->addr);
+	if (hlink)
+		snd_hdac_ext_bus_link_put(bus, hlink);
+	/*
+	 * HDMI card's hda_codec_probe_complete() (see late_probe()) may
+	 * not be called due to early error, leaving bus uc unbalanced
+	 */
+	if (!was_registered) {
+		pm_runtime_put_autosuspend(bus->dev);
+	}
+
+#ifdef CONFIG_PM
+	WARN_ON(atomic_read(&hdev->dev.power.usage_count) != 1 ||
+		!pm_runtime_status_suspended(&hdev->dev));
+#endif
+}
+
+static const struct snd_soc_dapm_route hda_dapm_routes[] = {
+	{"AIF1TX", NULL, "Codec Input Pin1"},
+	{"AIF2TX", NULL, "Codec Input Pin2"},
+	{"AIF3TX", NULL, "Codec Input Pin3"},
+
+	{"Codec Output Pin1", NULL, "AIF1RX"},
+	{"Codec Output Pin2", NULL, "AIF2RX"},
+	{"Codec Output Pin3", NULL, "AIF3RX"},
+};
+
+static const struct snd_soc_dapm_widget hda_dapm_widgets[] = {
+	/* Audio Interface */
+	SND_SOC_DAPM_AIF_IN("AIF1RX", "Analog Codec Playback", 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_AIF_IN("AIF2RX", "Digital Codec Playback", 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_AIF_IN("AIF3RX", "Alt Analog Codec Playback", 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_AIF_OUT("AIF1TX", "Analog Codec Capture", 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_AIF_OUT("AIF2TX", "Digital Codec Capture", 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_AIF_OUT("AIF3TX", "Alt Analog Codec Capture", 0, SND_SOC_NOPM, 0, 0),
+
+	/* Input Pins */
+	SND_SOC_DAPM_INPUT("Codec Input Pin1"),
+	SND_SOC_DAPM_INPUT("Codec Input Pin2"),
+	SND_SOC_DAPM_INPUT("Codec Input Pin3"),
+
+	/* Output Pins */
+	SND_SOC_DAPM_OUTPUT("Codec Output Pin1"),
+	SND_SOC_DAPM_OUTPUT("Codec Output Pin2"),
+	SND_SOC_DAPM_OUTPUT("Codec Output Pin3"),
+};
+
+static struct snd_soc_dai_driver card_binder_dai = {
+	.id = -1,
+	.name = "codec-probing-DAI",
+};
+
+static int hda_hdev_attach(struct hdac_device *hdev)
+{
+	struct hda_codec *codec = dev_to_hda_codec(&hdev->dev);
+	struct snd_soc_component_driver *comp_drv;
+
+	if (hda_codec_is_display(codec) && !hdev->bus->audio_component) {
+		dev_dbg(&hdev->dev, "no i915, skip registration for 0x%08x\n", hdev->vendor_id);
+		return -ENODEV;
+	}
+
+	comp_drv = devm_kzalloc(&hdev->dev, sizeof(*comp_drv), GFP_KERNEL);
+	if (!comp_drv)
+		return -ENOMEM;
+
+	/*
+	 * It's save to rely on dev_name() rather than a copy as component
+	 * driver's lifetime is directly tied to hda codec one
+	 */
+	comp_drv->name = dev_name(&hdev->dev);
+	comp_drv->probe = hda_codec_probe;
+	comp_drv->remove = hda_codec_remove;
+	comp_drv->idle_bias_on = false;
+	if (!hda_codec_is_display(codec)) {
+		comp_drv->dapm_widgets = hda_dapm_widgets;
+		comp_drv->num_dapm_widgets = ARRAY_SIZE(hda_dapm_widgets);
+		comp_drv->dapm_routes = hda_dapm_routes;
+		comp_drv->num_dapm_routes = ARRAY_SIZE(hda_dapm_routes);
+	}
+
+	return snd_soc_register_component(&hdev->dev, comp_drv, &card_binder_dai, 1);
+}
+
+static int hda_hdev_detach(struct hdac_device *hdev)
+{
+	struct hda_codec *codec = dev_to_hda_codec(&hdev->dev);
+
+	if (codec->core.registered)
+		cancel_delayed_work_sync(&codec->jackpoll_work);
+
+	snd_soc_unregister_component(&hdev->dev);
+
+	return 0;
+}
+
+const struct hdac_ext_bus_ops soc_hda_ext_bus_ops = {
+	.hdev_attach = hda_hdev_attach,
+	.hdev_detach = hda_hdev_detach,
+};
+EXPORT_SYMBOL_GPL(soc_hda_ext_bus_ops);
+
+MODULE_DESCRIPTION("HD-Audio codec driver");
+MODULE_AUTHOR("Cezary Rojewski <cezary.rojewski@intel.com>");
+MODULE_LICENSE("GPL");