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, 251 insertions, 0 deletions

diff --git a/drivers/hid/hid-tmff.c b/drivers/hid/hid-tmff.c
new file mode 100644
index 000000000..303769b07
--- /dev/null
+++ b/drivers/hid/hid-tmff.c
@@ -0,0 +1,251 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Force feedback support for various HID compliant devices by ThrustMaster:
+ *    ThrustMaster FireStorm Dual Power 2
+ * and possibly others whose device ids haven't been added.
+ *
+ *  Modified to support ThrustMaster devices by Zinx Verituse
+ *  on 2003-01-25 from the Logitech force feedback driver,
+ *  which is by Johann Deneux.
+ *
+ *  Copyright (c) 2003 Zinx Verituse <zinx@epicsol.org>
+ *  Copyright (c) 2002 Johann Deneux
+ */
+
+/*
+ */
+
+#include <linux/hid.h>
+#include <linux/input.h>
+#include <linux/math64.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+#define THRUSTMASTER_DEVICE_ID_2_IN_1_DT	0xb320
+
+static const signed short ff_rumble[] = {
+	FF_RUMBLE,
+	-1
+};
+
+static const signed short ff_joystick[] = {
+	FF_CONSTANT,
+	-1
+};
+
+#ifdef CONFIG_THRUSTMASTER_FF
+
+/* Usages for thrustmaster devices I know about */
+#define THRUSTMASTER_USAGE_FF	(HID_UP_GENDESK | 0xbb)
+
+struct tmff_device {
+	struct hid_report *report;
+	struct hid_field *ff_field;
+};
+
+/* Changes values from 0 to 0xffff into values from minimum to maximum */
+static inline int tmff_scale_u16(unsigned int in, int minimum, int maximum)
+{
+	s64 ret;
+
+	ret = div_s64((s64)in * ((s64)maximum - minimum), 0xffff) + minimum;
+	if (ret < minimum)
+		return minimum;
+	if (ret > maximum)
+		return maximum;
+	return ret;
+}
+
+/* Changes values from -0x80 to 0x7f into values from minimum to maximum */
+static inline int tmff_scale_s8(int in, int minimum, int maximum)
+{
+	s64 ret;
+
+	ret = div_s64((s64)(in + 0x80) * ((s64)maximum - minimum), 0xff) + minimum;
+	if (ret < minimum)
+		return minimum;
+	if (ret > maximum)
+		return maximum;
+	return ret;
+}
+
+static int tmff_play(struct input_dev *dev, void *data,
+		struct ff_effect *effect)
+{
+	struct hid_device *hid = input_get_drvdata(dev);
+	struct tmff_device *tmff = data;
+	struct hid_field *ff_field = tmff->ff_field;
+	int x, y;
+	int left, right;	/* Rumbling */
+
+	switch (effect->type) {
+	case FF_CONSTANT:
+		x = tmff_scale_s8(effect->u.ramp.start_level,
+					ff_field->logical_minimum,
+					ff_field->logical_maximum);
+		y = tmff_scale_s8(effect->u.ramp.end_level,
+					ff_field->logical_minimum,
+					ff_field->logical_maximum);
+
+		dbg_hid("(x, y)=(%04x, %04x)\n", x, y);
+		ff_field->value[0] = x;
+		ff_field->value[1] = y;
+		hid_hw_request(hid, tmff->report, HID_REQ_SET_REPORT);
+		break;
+
+	case FF_RUMBLE:
+		left = tmff_scale_u16(effect->u.rumble.weak_magnitude,
+					ff_field->logical_minimum,
+					ff_field->logical_maximum);
+		right = tmff_scale_u16(effect->u.rumble.strong_magnitude,
+					ff_field->logical_minimum,
+					ff_field->logical_maximum);
+
+		/* 2-in-1 strong motor is left */
+		if (hid->product == THRUSTMASTER_DEVICE_ID_2_IN_1_DT)
+			swap(left, right);
+
+		dbg_hid("(left,right)=(%08x, %08x)\n", left, right);
+		ff_field->value[0] = left;
+		ff_field->value[1] = right;
+		hid_hw_request(hid, tmff->report, HID_REQ_SET_REPORT);
+		break;
+	}
+	return 0;
+}
+
+static int tm_input_configured(struct hid_device *hid, struct hid_input *hidinput)
+{
+	struct tmff_device *tmff;
+	struct hid_report *report;
+	struct list_head *report_list;
+	struct input_dev *input_dev = hidinput->input;
+	const struct hid_device_id *id;
+	const signed short *ff_bits;
+	int error;
+	int i;
+
+	if (!list_is_first(&hidinput->list, &hid->inputs))
+		return 0;
+
+	id = hid_match_device(hid, hid->driver);
+	if (!id)
+		return -ENODEV;
+
+	ff_bits = (void *)id->driver_data;
+
+	tmff = kzalloc_obj(struct tmff_device);
+	if (!tmff)
+		return -ENOMEM;
+
+	/* Find the report to use */
+	report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
+	list_for_each_entry(report, report_list, list) {
+		int fieldnum;
+
+		for (fieldnum = 0; fieldnum < report->maxfield; ++fieldnum) {
+			struct hid_field *field = report->field[fieldnum];
+
+			if (field->maxusage <= 0)
+				continue;
+
+			switch (field->usage[0].hid) {
+			case THRUSTMASTER_USAGE_FF:
+				if (field->report_count < 2) {
+					hid_warn(hid, "ignoring FF field with report_count < 2\n");
+					continue;
+				}
+
+				if (field->logical_maximum ==
+						field->logical_minimum) {
+					hid_warn(hid, "ignoring FF field with logical_maximum == logical_minimum\n");
+					continue;
+				}
+
+				if (tmff->report && tmff->report != report) {
+					hid_warn(hid, "ignoring FF field in other report\n");
+					continue;
+				}
+
+				if (tmff->ff_field && tmff->ff_field != field) {
+					hid_warn(hid, "ignoring duplicate FF field\n");
+					continue;
+				}
+
+				tmff->report = report;
+				tmff->ff_field = field;
+
+				for (i = 0; ff_bits[i] >= 0; i++)
+					set_bit(ff_bits[i], input_dev->ffbit);
+
+				break;
+
+			default:
+				hid_warn(hid, "ignoring unknown output usage %08x\n",
+					 field->usage[0].hid);
+				continue;
+			}
+		}
+	}
+
+	if (!tmff->report) {
+		hid_err(hid, "can't find FF field in output reports\n");
+		error = -ENODEV;
+		goto fail;
+	}
+
+	error = input_ff_create_memless(input_dev, tmff, tmff_play);
+	if (error)
+		goto fail;
+
+	hid_info(hid, "force feedback for ThrustMaster devices by Zinx Verituse <zinx@epicsol.org>\n");
+	return 0;
+
+fail:
+	kfree(tmff);
+	return error;
+}
+#else
+static inline int tm_input_configured(struct hid_device *hid,
+				      struct hid_input *hidinput)
+{
+	return 0;
+}
+#endif
+
+static const struct hid_device_id tm_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb300),
+		.driver_data = (unsigned long)ff_rumble },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb304),   /* FireStorm Dual Power 2 (and 3) */
+		.driver_data = (unsigned long)ff_rumble },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, THRUSTMASTER_DEVICE_ID_2_IN_1_DT),   /* Dual Trigger 2-in-1 */
+		.driver_data = (unsigned long)ff_rumble },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb323),   /* Dual Trigger 3-in-1 (PC Mode) */
+		.driver_data = (unsigned long)ff_rumble },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb324),   /* Dual Trigger 3-in-1 (PS3 Mode) */
+		.driver_data = (unsigned long)ff_rumble },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb605),   /* NASCAR PRO FF2 Wheel */
+		.driver_data = (unsigned long)ff_joystick },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb651),	/* FGT Rumble Force Wheel */
+		.driver_data = (unsigned long)ff_rumble },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb653),	/* RGT Force Feedback CLUTCH Raging Wheel */
+		.driver_data = (unsigned long)ff_joystick },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb654),	/* FGT Force Feedback Wheel */
+		.driver_data = (unsigned long)ff_joystick },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb65a),	/* F430 Force Feedback Wheel */
+		.driver_data = (unsigned long)ff_joystick },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, tm_devices);
+
+static struct hid_driver tm_driver = {
+	.name = "thrustmaster",
+	.id_table = tm_devices,
+	.input_configured = tm_input_configured,
+};
+module_hid_driver(tm_driver);
+
+MODULE_DESCRIPTION("Force feedback support for various HID compliant devices by ThrustMaster");
+MODULE_LICENSE("GPL");