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, 135 insertions, 0 deletions

diff --git a/drivers/hid/hid-twinhan.c b/drivers/hid/hid-twinhan.c
new file mode 100644
index 000000000..0ef519408
--- /dev/null
+++ b/drivers/hid/hid-twinhan.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * HID driver for TwinHan IR remote control
+ *
+ * Based on hid-gyration.c
+ *
+ * Copyright (c) 2009 Bruno Prémont <bonbons@linux-vserver.org>
+ */
+
+/*
+ */
+
+#include <linux/device.h>
+#include <linux/input.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+/*	Remote control key layout + listing:
+ *
+ * 	Full Screen                              Power
+ *	KEY_SCREEN                          KEY_POWER2
+ *
+ *	1                     2                      3
+ *	KEY_NUMERIC_1   KEY_NUMERIC_2    KEY_NUMERIC_3
+ *
+ *	4                     5                      6
+ *	KEY_NUMERIC_4   KEY_NUMERIC_5    KEY_NUMERIC_6
+ *
+ *	7                     8                      9
+ *	KEY_NUMERIC_7   KEY_NUMERIC_8    KEY_NUMERIC_9
+ *
+ *	REC                   0               Favorite
+ *	KEY_RECORD      KEY_NUMERIC_0    KEY_FAVORITES
+ *
+ *	Rewind                                 Forward
+ *	KEY_REWIND           CH+           KEY_FORWARD
+ *	               KEY_CHANNELUP
+ *
+ *	VOL-                  >                   VOL+
+ *	KEY_VOLUMEDOWN    KEY_PLAY        KEY_VOLUMEUP
+ *
+ *	                     CH-
+ *	              KEY_CHANNELDOWN
+ *	Recall                                    Stop
+ *	KEY_RESTART                           KEY_STOP
+ *
+ *	Timeshift/Pause     Mute                Cancel
+ *	KEY_PAUSE         KEY_MUTE          KEY_CANCEL
+ *
+ *	Capture            Preview                 EPG
+ *	KEY_PRINT        KEY_PROGRAM           KEY_EPG
+ *
+ *	Record List          Tab              Teletext
+ *	KEY_LIST            KEY_TAB           KEY_TEXT
+ */
+
+#define th_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
+					EV_KEY, (c))
+static int twinhan_input_mapping(struct hid_device *hdev, struct hid_input *hi,
+		struct hid_field *field, struct hid_usage *usage,
+		unsigned long **bit, int *max)
+{
+	if ((usage->hid & HID_USAGE_PAGE) != HID_UP_KEYBOARD)
+		return 0;
+
+	switch (usage->hid & HID_USAGE) {
+	/* Map all keys from Twinhan Remote */
+	case 0x004: th_map_key_clear(KEY_TEXT);         break;
+	case 0x006: th_map_key_clear(KEY_RESTART);      break;
+	case 0x008: th_map_key_clear(KEY_EPG);          break;
+	case 0x00c: th_map_key_clear(KEY_REWIND);       break;
+	case 0x00e: th_map_key_clear(KEY_PROGRAM);      break;
+	case 0x00f: th_map_key_clear(KEY_LIST);         break;
+	case 0x010: th_map_key_clear(KEY_MUTE);         break;
+	case 0x011: th_map_key_clear(KEY_FORWARD);      break;
+	case 0x013: th_map_key_clear(KEY_PRINT);        break;
+	case 0x017: th_map_key_clear(KEY_PAUSE);        break;
+	case 0x019: th_map_key_clear(KEY_FAVORITES);    break;
+	case 0x01d: th_map_key_clear(KEY_SCREEN);       break;
+	case 0x01e: th_map_key_clear(KEY_NUMERIC_1);    break;
+	case 0x01f: th_map_key_clear(KEY_NUMERIC_2);    break;
+	case 0x020: th_map_key_clear(KEY_NUMERIC_3);    break;
+	case 0x021: th_map_key_clear(KEY_NUMERIC_4);    break;
+	case 0x022: th_map_key_clear(KEY_NUMERIC_5);    break;
+	case 0x023: th_map_key_clear(KEY_NUMERIC_6);    break;
+	case 0x024: th_map_key_clear(KEY_NUMERIC_7);    break;
+	case 0x025: th_map_key_clear(KEY_NUMERIC_8);    break;
+	case 0x026: th_map_key_clear(KEY_NUMERIC_9);    break;
+	case 0x027: th_map_key_clear(KEY_NUMERIC_0);    break;
+	case 0x028: th_map_key_clear(KEY_PLAY);         break;
+	case 0x029: th_map_key_clear(KEY_CANCEL);       break;
+	case 0x02b: th_map_key_clear(KEY_TAB);          break;
+	/* Power       = 0x0e0 + 0x0e1 + 0x0e2 + 0x03f */
+	case 0x03f: th_map_key_clear(KEY_POWER2);       break;
+	case 0x04a: th_map_key_clear(KEY_RECORD);       break;
+	case 0x04b: th_map_key_clear(KEY_CHANNELUP);    break;
+	case 0x04d: th_map_key_clear(KEY_STOP);         break;
+	case 0x04e: th_map_key_clear(KEY_CHANNELDOWN);  break;
+	/* Volume down = 0x0e1 + 0x051                 */
+	case 0x051: th_map_key_clear(KEY_VOLUMEDOWN);   break;
+	/* Volume up   = 0x0e1 + 0x052                 */
+	case 0x052: th_map_key_clear(KEY_VOLUMEUP);     break;
+	/* Kill the extra keys used for multi-key "power" and "volume" keys
+	 * as well as continuously to release CTRL,ALT,META,... keys */
+	case 0x0e0:
+	case 0x0e1:
+	case 0x0e2:
+	case 0x0e3:
+	case 0x0e4:
+	case 0x0e5:
+	case 0x0e6:
+	case 0x0e7:
+	default:
+		return -1;
+	}
+	return 1;
+}
+
+static const struct hid_device_id twinhan_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_TWINHAN, USB_DEVICE_ID_TWINHAN_IR_REMOTE) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, twinhan_devices);
+
+static struct hid_driver twinhan_driver = {
+	.name = "twinhan",
+	.id_table = twinhan_devices,
+	.input_mapping = twinhan_input_mapping,
+};
+module_hid_driver(twinhan_driver);
+
+MODULE_DESCRIPTION("HID driver for TwinHan IR remote control");
+MODULE_LICENSE("GPL");