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, 250 insertions, 0 deletions

diff --git a/drivers/hid/hid-plantronics.c b/drivers/hid/hid-plantronics.c
new file mode 100644
index 000000000..acb9eb18f
--- /dev/null
+++ b/drivers/hid/hid-plantronics.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Plantronics USB HID Driver
+ *
+ *  Copyright (c) 2014 JD Cole <jd.cole@plantronics.com>
+ *  Copyright (c) 2015-2018 Terry Junge <terry.junge@plantronics.com>
+ */
+
+#include "hid-ids.h"
+
+#include <linux/hid.h>
+#include <linux/module.h>
+#include <linux/jiffies.h>
+
+#define PLT_HID_1_0_PAGE	0xffa00000
+#define PLT_HID_2_0_PAGE	0xffa20000
+
+#define PLT_BASIC_TELEPHONY	0x0003
+#define PLT_BASIC_EXCEPTION	0x0005
+
+#define PLT_VOL_UP		0x00b1
+#define PLT_VOL_DOWN		0x00b2
+#define PLT_MIC_MUTE		0x00b5
+
+#define PLT1_VOL_UP		(PLT_HID_1_0_PAGE | PLT_VOL_UP)
+#define PLT1_VOL_DOWN		(PLT_HID_1_0_PAGE | PLT_VOL_DOWN)
+#define PLT1_MIC_MUTE		(PLT_HID_1_0_PAGE | PLT_MIC_MUTE)
+#define PLT2_VOL_UP		(PLT_HID_2_0_PAGE | PLT_VOL_UP)
+#define PLT2_VOL_DOWN		(PLT_HID_2_0_PAGE | PLT_VOL_DOWN)
+#define PLT2_MIC_MUTE		(PLT_HID_2_0_PAGE | PLT_MIC_MUTE)
+#define HID_TELEPHONY_MUTE	(HID_UP_TELEPHONY | 0x2f)
+#define HID_CONSUMER_MUTE	(HID_UP_CONSUMER | 0xe2)
+
+#define PLT_DA60		0xda60
+#define PLT_BT300_MIN		0x0413
+#define PLT_BT300_MAX		0x0418
+
+#define PLT_DOUBLE_KEY_TIMEOUT 5 /* ms */
+
+struct plt_drv_data {
+	unsigned long device_type;
+	unsigned long last_key_ts;
+	unsigned long double_key_to;
+	__u16 last_key;
+};
+
+static int plantronics_input_mapping(struct hid_device *hdev,
+				     struct hid_input *hi,
+				     struct hid_field *field,
+				     struct hid_usage *usage,
+				     unsigned long **bit, int *max)
+{
+	unsigned short mapped_key;
+	struct plt_drv_data *drv_data = hid_get_drvdata(hdev);
+	unsigned long plt_type = drv_data->device_type;
+	int allow_mute = usage->hid == HID_TELEPHONY_MUTE;
+	int allow_consumer = field->application == HID_CP_CONSUMERCONTROL &&
+			(usage->hid & HID_USAGE_PAGE) == HID_UP_CONSUMER &&
+			usage->hid != HID_CONSUMER_MUTE;
+
+	/* special case for PTT products */
+	if (field->application == HID_GD_JOYSTICK)
+		goto defaulted;
+
+	/* non-standard types or multi-HID interfaces - plt_type is PID */
+	if (!(plt_type & HID_USAGE_PAGE)) {
+		switch (plt_type) {
+		case PLT_DA60:
+			if (allow_consumer)
+				goto defaulted;
+			if (usage->hid == HID_CONSUMER_MUTE) {
+				mapped_key = KEY_MICMUTE;
+				goto mapped;
+			}
+			break;
+		default:
+			if (allow_consumer || allow_mute)
+				goto defaulted;
+		}
+		goto ignored;
+	}
+
+	/* handle standard consumer control mapping */
+	/* and standard telephony mic mute mapping */
+	if (allow_consumer || allow_mute)
+		goto defaulted;
+
+	/* handle vendor unique types - plt_type is 0xffa0uuuu or 0xffa2uuuu */
+	/* if not 'basic telephony compliant' - map vendor unique controls */
+	if (!((plt_type & HID_USAGE) >= PLT_BASIC_TELEPHONY &&
+	      (plt_type & HID_USAGE) != PLT_BASIC_EXCEPTION) &&
+	      !((field->application ^ plt_type) & HID_USAGE_PAGE))
+		switch (usage->hid) {
+		case PLT1_VOL_UP:
+		case PLT2_VOL_UP:
+			mapped_key = KEY_VOLUMEUP;
+			goto mapped;
+		case PLT1_VOL_DOWN:
+		case PLT2_VOL_DOWN:
+			mapped_key = KEY_VOLUMEDOWN;
+			goto mapped;
+		case PLT1_MIC_MUTE:
+		case PLT2_MIC_MUTE:
+			mapped_key = KEY_MICMUTE;
+			goto mapped;
+		}
+
+/*
+ * Future mapping of call control or other usages,
+ * if and when keys are defined would go here
+ * otherwise, ignore everything else that was not mapped
+ */
+
+ignored:
+	hid_dbg(hdev, "usage: %08x (appl: %08x) - ignored\n",
+		usage->hid, field->application);
+	return -1;
+
+defaulted:
+	hid_dbg(hdev, "usage: %08x (appl: %08x) - defaulted\n",
+		usage->hid, field->application);
+	return 0;
+
+mapped:
+	hid_map_usage_clear(hi, usage, bit, max, EV_KEY, mapped_key);
+	hid_dbg(hdev, "usage: %08x (appl: %08x) - mapped to key %d\n",
+		usage->hid, field->application, mapped_key);
+	return 1;
+}
+
+static int plantronics_event(struct hid_device *hdev, struct hid_field *field,
+			     struct hid_usage *usage, __s32 value)
+{
+	struct plt_drv_data *drv_data = hid_get_drvdata(hdev);
+	unsigned long prev_tsto, cur_ts;
+	__u16 prev_key, cur_key;
+
+	/* Usages are filtered in plantronics_usages. */
+
+	/* HZ too low for ms resolution - double key detection disabled */
+	/* or it is a key release - handle key presses only. */
+	if (!drv_data->double_key_to || !value)
+		return 0;
+
+	prev_tsto = drv_data->last_key_ts + drv_data->double_key_to;
+	cur_ts = drv_data->last_key_ts = jiffies;
+	prev_key = drv_data->last_key;
+	cur_key = drv_data->last_key = usage->code;
+
+	/* If the same key occurs in <= double_key_to -- ignore it */
+	if (prev_key == cur_key && time_before_eq(cur_ts, prev_tsto)) {
+		hid_dbg(hdev, "double key %d ignored\n", cur_key);
+		return 1; /* Ignore the repeated key. */
+	}
+	return 0;
+}
+
+static unsigned long plantronics_device_type(struct hid_device *hdev)
+{
+	unsigned i, col_page;
+	unsigned long plt_type = hdev->product;
+
+	/* multi-HID interfaces? - plt_type is PID */
+	if (plt_type >= PLT_BT300_MIN && plt_type <= PLT_BT300_MAX)
+		goto exit;
+
+	/* determine primary vendor page */
+	for (i = 0; i < hdev->maxcollection; i++) {
+		col_page = hdev->collection[i].usage & HID_USAGE_PAGE;
+		if (col_page == PLT_HID_2_0_PAGE) {
+			plt_type = hdev->collection[i].usage;
+			break;
+		}
+		if (col_page == PLT_HID_1_0_PAGE)
+			plt_type = hdev->collection[i].usage;
+	}
+
+exit:
+	hid_dbg(hdev, "plt_type decoded as: %08lx\n", plt_type);
+	return plt_type;
+}
+
+static int plantronics_probe(struct hid_device *hdev,
+			     const struct hid_device_id *id)
+{
+	struct plt_drv_data *drv_data;
+	int ret;
+
+	drv_data = devm_kzalloc(&hdev->dev, sizeof(*drv_data), GFP_KERNEL);
+	if (!drv_data)
+		return -ENOMEM;
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "parse failed\n");
+		return ret;
+	}
+
+	drv_data->device_type = plantronics_device_type(hdev);
+	drv_data->double_key_to = msecs_to_jiffies(PLT_DOUBLE_KEY_TIMEOUT);
+	drv_data->last_key_ts = jiffies - drv_data->double_key_to;
+
+	/* if HZ does not allow ms resolution - disable double key detection */
+	if (drv_data->double_key_to < PLT_DOUBLE_KEY_TIMEOUT)
+		drv_data->double_key_to = 0;
+
+	hid_set_drvdata(hdev, drv_data);
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT |
+		HID_CONNECT_HIDINPUT_FORCE | HID_CONNECT_HIDDEV_FORCE);
+	if (ret)
+		hid_err(hdev, "hw start failed\n");
+
+	return ret;
+}
+
+static const struct hid_device_id plantronics_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_PLANTRONICS, HID_ANY_ID) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, plantronics_devices);
+
+static const struct hid_usage_id plantronics_usages[] = {
+	{ HID_CP_VOLUMEUP, EV_KEY, HID_ANY_ID },
+	{ HID_CP_VOLUMEDOWN, EV_KEY, HID_ANY_ID },
+	{ HID_TELEPHONY_MUTE, EV_KEY, HID_ANY_ID },
+	{ HID_CONSUMER_MUTE, EV_KEY, HID_ANY_ID },
+	{ PLT2_VOL_UP, EV_KEY, HID_ANY_ID },
+	{ PLT2_VOL_DOWN, EV_KEY, HID_ANY_ID },
+	{ PLT2_MIC_MUTE, EV_KEY, HID_ANY_ID },
+	{ PLT1_VOL_UP, EV_KEY, HID_ANY_ID },
+	{ PLT1_VOL_DOWN, EV_KEY, HID_ANY_ID },
+	{ PLT1_MIC_MUTE, EV_KEY, HID_ANY_ID },
+	{ HID_TERMINATOR, HID_TERMINATOR, HID_TERMINATOR }
+};
+
+static struct hid_driver plantronics_driver = {
+	.name = "plantronics",
+	.id_table = plantronics_devices,
+	.usage_table = plantronics_usages,
+	.input_mapping = plantronics_input_mapping,
+	.event = plantronics_event,
+	.probe = plantronics_probe,
+};
+module_hid_driver(plantronics_driver);
+
+MODULE_AUTHOR("JD Cole <jd.cole@plantronics.com>");
+MODULE_AUTHOR("Terry Junge <terry.junge@plantronics.com>");
+MODULE_DESCRIPTION("Plantronics USB HID Driver");
+MODULE_LICENSE("GPL");