From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions 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) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- drivers/hid/hid-led.c | 535 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 535 insertions(+) create mode 100644 drivers/hid/hid-led.c (limited to 'drivers/hid/hid-led.c') diff --git a/drivers/hid/hid-led.c b/drivers/hid/hid-led.c new file mode 100644 index 000000000..7d82f8d42 --- /dev/null +++ b/drivers/hid/hid-led.c @@ -0,0 +1,535 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Simple USB RGB LED driver + * + * Copyright 2016 Heiner Kallweit + * Based on drivers/hid/hid-thingm.c and + * drivers/usb/misc/usbled.c + */ + +#include +#include +#include +#include +#include + +#include "hid-ids.h" + +enum hidled_report_type { + RAW_REQUEST, + OUTPUT_REPORT +}; + +enum hidled_type { + RISO_KAGAKU, + DREAM_CHEEKY, + THINGM, + DELCOM, + LUXAFOR, +}; + +static unsigned const char riso_kagaku_tbl[] = { +/* R+2G+4B -> riso kagaku color index */ + [0] = 0, /* black */ + [1] = 2, /* red */ + [2] = 1, /* green */ + [3] = 5, /* yellow */ + [4] = 3, /* blue */ + [5] = 6, /* magenta */ + [6] = 4, /* cyan */ + [7] = 7 /* white */ +}; + +#define RISO_KAGAKU_IX(r, g, b) riso_kagaku_tbl[((r)?1:0)+((g)?2:0)+((b)?4:0)] + +union delcom_packet { + __u8 data[8]; + struct { + __u8 major_cmd; + __u8 minor_cmd; + __u8 data_lsb; + __u8 data_msb; + } tx; + struct { + __u8 cmd; + } rx; + struct { + __le16 family_code; + __le16 security_code; + __u8 fw_version; + } fw; +}; + +#define DELCOM_GREEN_LED 0 +#define DELCOM_RED_LED 1 +#define DELCOM_BLUE_LED 2 + +struct hidled_device; +struct hidled_rgb; + +struct hidled_config { + enum hidled_type type; + const char *name; + const char *short_name; + enum led_brightness max_brightness; + int num_leds; + size_t report_size; + enum hidled_report_type report_type; + int (*init)(struct hidled_device *ldev); + int (*write)(struct led_classdev *cdev, enum led_brightness br); +}; + +struct hidled_led { + struct led_classdev cdev; + struct hidled_rgb *rgb; + char name[32]; +}; + +struct hidled_rgb { + struct hidled_device *ldev; + struct hidled_led red; + struct hidled_led green; + struct hidled_led blue; + u8 num; +}; + +struct hidled_device { + const struct hidled_config *config; + struct hid_device *hdev; + struct hidled_rgb *rgb; + u8 *buf; + struct mutex lock; +}; + +#define MAX_REPORT_SIZE 16 + +#define to_hidled_led(arg) container_of(arg, struct hidled_led, cdev) + +static bool riso_kagaku_switch_green_blue; +module_param(riso_kagaku_switch_green_blue, bool, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(riso_kagaku_switch_green_blue, + "switch green and blue RGB component for Riso Kagaku devices"); + +static int hidled_send(struct hidled_device *ldev, __u8 *buf) +{ + int ret; + + mutex_lock(&ldev->lock); + + /* + * buffer provided to hid_hw_raw_request must not be on the stack + * and must not be part of a data structure + */ + memcpy(ldev->buf, buf, ldev->config->report_size); + + if (ldev->config->report_type == RAW_REQUEST) + ret = hid_hw_raw_request(ldev->hdev, buf[0], ldev->buf, + ldev->config->report_size, + HID_FEATURE_REPORT, + HID_REQ_SET_REPORT); + else if (ldev->config->report_type == OUTPUT_REPORT) + ret = hid_hw_output_report(ldev->hdev, ldev->buf, + ldev->config->report_size); + else + ret = -EINVAL; + + mutex_unlock(&ldev->lock); + + if (ret < 0) + return ret; + + return ret == ldev->config->report_size ? 0 : -EMSGSIZE; +} + +/* reading data is supported for report type RAW_REQUEST only */ +static int hidled_recv(struct hidled_device *ldev, __u8 *buf) +{ + int ret; + + if (ldev->config->report_type != RAW_REQUEST) + return -EINVAL; + + mutex_lock(&ldev->lock); + + memcpy(ldev->buf, buf, ldev->config->report_size); + + ret = hid_hw_raw_request(ldev->hdev, buf[0], ldev->buf, + ldev->config->report_size, + HID_FEATURE_REPORT, + HID_REQ_SET_REPORT); + if (ret < 0) + goto err; + + ret = hid_hw_raw_request(ldev->hdev, buf[0], ldev->buf, + ldev->config->report_size, + HID_FEATURE_REPORT, + HID_REQ_GET_REPORT); + + memcpy(buf, ldev->buf, ldev->config->report_size); +err: + mutex_unlock(&ldev->lock); + + return ret < 0 ? ret : 0; +} + +static u8 riso_kagaku_index(struct hidled_rgb *rgb) +{ + enum led_brightness r, g, b; + + r = rgb->red.cdev.brightness; + g = rgb->green.cdev.brightness; + b = rgb->blue.cdev.brightness; + + if (riso_kagaku_switch_green_blue) + return RISO_KAGAKU_IX(r, b, g); + else + return RISO_KAGAKU_IX(r, g, b); +} + +static int riso_kagaku_write(struct led_classdev *cdev, enum led_brightness br) +{ + struct hidled_led *led = to_hidled_led(cdev); + struct hidled_rgb *rgb = led->rgb; + __u8 buf[MAX_REPORT_SIZE] = {}; + + buf[1] = riso_kagaku_index(rgb); + + return hidled_send(rgb->ldev, buf); +} + +static int dream_cheeky_write(struct led_classdev *cdev, enum led_brightness br) +{ + struct hidled_led *led = to_hidled_led(cdev); + struct hidled_rgb *rgb = led->rgb; + __u8 buf[MAX_REPORT_SIZE] = {}; + + buf[1] = rgb->red.cdev.brightness; + buf[2] = rgb->green.cdev.brightness; + buf[3] = rgb->blue.cdev.brightness; + buf[7] = 0x1a; + buf[8] = 0x05; + + return hidled_send(rgb->ldev, buf); +} + +static int dream_cheeky_init(struct hidled_device *ldev) +{ + __u8 buf[MAX_REPORT_SIZE] = {}; + + /* Dream Cheeky magic */ + buf[1] = 0x1f; + buf[2] = 0x02; + buf[4] = 0x5f; + buf[7] = 0x1a; + buf[8] = 0x03; + + return hidled_send(ldev, buf); +} + +static int _thingm_write(struct led_classdev *cdev, enum led_brightness br, + u8 offset) +{ + struct hidled_led *led = to_hidled_led(cdev); + __u8 buf[MAX_REPORT_SIZE] = { 1, 'c' }; + + buf[2] = led->rgb->red.cdev.brightness; + buf[3] = led->rgb->green.cdev.brightness; + buf[4] = led->rgb->blue.cdev.brightness; + buf[7] = led->rgb->num + offset; + + return hidled_send(led->rgb->ldev, buf); +} + +static int thingm_write_v1(struct led_classdev *cdev, enum led_brightness br) +{ + return _thingm_write(cdev, br, 0); +} + +static int thingm_write(struct led_classdev *cdev, enum led_brightness br) +{ + return _thingm_write(cdev, br, 1); +} + +static const struct hidled_config hidled_config_thingm_v1 = { + .name = "ThingM blink(1) v1", + .short_name = "thingm", + .max_brightness = 255, + .num_leds = 1, + .report_size = 9, + .report_type = RAW_REQUEST, + .write = thingm_write_v1, +}; + +static int thingm_init(struct hidled_device *ldev) +{ + __u8 buf[MAX_REPORT_SIZE] = { 1, 'v' }; + int ret; + + ret = hidled_recv(ldev, buf); + if (ret) + return ret; + + /* Check for firmware major version 1 */ + if (buf[3] == '1') + ldev->config = &hidled_config_thingm_v1; + + return 0; +} + +static inline int delcom_get_lednum(const struct hidled_led *led) +{ + if (led == &led->rgb->red) + return DELCOM_RED_LED; + else if (led == &led->rgb->green) + return DELCOM_GREEN_LED; + else + return DELCOM_BLUE_LED; +} + +static int delcom_enable_led(struct hidled_led *led) +{ + union delcom_packet dp = { .tx.major_cmd = 101, .tx.minor_cmd = 12 }; + + dp.tx.data_lsb = 1 << delcom_get_lednum(led); + dp.tx.data_msb = 0; + + return hidled_send(led->rgb->ldev, dp.data); +} + +static int delcom_set_pwm(struct hidled_led *led) +{ + union delcom_packet dp = { .tx.major_cmd = 101, .tx.minor_cmd = 34 }; + + dp.tx.data_lsb = delcom_get_lednum(led); + dp.tx.data_msb = led->cdev.brightness; + + return hidled_send(led->rgb->ldev, dp.data); +} + +static int delcom_write(struct led_classdev *cdev, enum led_brightness br) +{ + struct hidled_led *led = to_hidled_led(cdev); + int ret; + + /* + * enable LED + * We can't do this in the init function already because the device + * is internally reset later. + */ + ret = delcom_enable_led(led); + if (ret) + return ret; + + return delcom_set_pwm(led); +} + +static int delcom_init(struct hidled_device *ldev) +{ + union delcom_packet dp = { .rx.cmd = 104 }; + int ret; + + ret = hidled_recv(ldev, dp.data); + if (ret) + return ret; + /* + * Several Delcom devices share the same USB VID/PID + * Check for family id 2 for Visual Signal Indicator + */ + return le16_to_cpu(dp.fw.family_code) == 2 ? 0 : -ENODEV; +} + +static int luxafor_write(struct led_classdev *cdev, enum led_brightness br) +{ + struct hidled_led *led = to_hidled_led(cdev); + __u8 buf[MAX_REPORT_SIZE] = { [1] = 1 }; + + buf[2] = led->rgb->num + 1; + buf[3] = led->rgb->red.cdev.brightness; + buf[4] = led->rgb->green.cdev.brightness; + buf[5] = led->rgb->blue.cdev.brightness; + + return hidled_send(led->rgb->ldev, buf); +} + +static const struct hidled_config hidled_configs[] = { + { + .type = RISO_KAGAKU, + .name = "Riso Kagaku Webmail Notifier", + .short_name = "riso_kagaku", + .max_brightness = 1, + .num_leds = 1, + .report_size = 6, + .report_type = OUTPUT_REPORT, + .write = riso_kagaku_write, + }, + { + .type = DREAM_CHEEKY, + .name = "Dream Cheeky Webmail Notifier", + .short_name = "dream_cheeky", + .max_brightness = 63, + .num_leds = 1, + .report_size = 9, + .report_type = RAW_REQUEST, + .init = dream_cheeky_init, + .write = dream_cheeky_write, + }, + { + .type = THINGM, + .name = "ThingM blink(1)", + .short_name = "thingm", + .max_brightness = 255, + .num_leds = 2, + .report_size = 9, + .report_type = RAW_REQUEST, + .init = thingm_init, + .write = thingm_write, + }, + { + .type = DELCOM, + .name = "Delcom Visual Signal Indicator G2", + .short_name = "delcom", + .max_brightness = 100, + .num_leds = 1, + .report_size = 8, + .report_type = RAW_REQUEST, + .init = delcom_init, + .write = delcom_write, + }, + { + .type = LUXAFOR, + .name = "Greynut Luxafor", + .short_name = "luxafor", + .max_brightness = 255, + .num_leds = 6, + .report_size = 9, + .report_type = OUTPUT_REPORT, + .write = luxafor_write, + }, +}; + +static int hidled_init_led(struct hidled_led *led, const char *color_name, + struct hidled_rgb *rgb, unsigned int minor) +{ + const struct hidled_config *config = rgb->ldev->config; + + if (config->num_leds > 1) + snprintf(led->name, sizeof(led->name), "%s%u:%s:led%u", + config->short_name, minor, color_name, rgb->num); + else + snprintf(led->name, sizeof(led->name), "%s%u:%s", + config->short_name, minor, color_name); + led->cdev.name = led->name; + led->cdev.max_brightness = config->max_brightness; + led->cdev.brightness_set_blocking = config->write; + led->cdev.flags = LED_HW_PLUGGABLE; + led->rgb = rgb; + + return devm_led_classdev_register(&rgb->ldev->hdev->dev, &led->cdev); +} + +static int hidled_init_rgb(struct hidled_rgb *rgb, unsigned int minor) +{ + int ret; + + /* Register the red diode */ + ret = hidled_init_led(&rgb->red, "red", rgb, minor); + if (ret) + return ret; + + /* Register the green diode */ + ret = hidled_init_led(&rgb->green, "green", rgb, minor); + if (ret) + return ret; + + /* Register the blue diode */ + return hidled_init_led(&rgb->blue, "blue", rgb, minor); +} + +static int hidled_probe(struct hid_device *hdev, const struct hid_device_id *id) +{ + struct hidled_device *ldev; + unsigned int minor; + int ret, i; + + ldev = devm_kzalloc(&hdev->dev, sizeof(*ldev), GFP_KERNEL); + if (!ldev) + return -ENOMEM; + + ldev->buf = devm_kmalloc(&hdev->dev, MAX_REPORT_SIZE, GFP_KERNEL); + if (!ldev->buf) + return -ENOMEM; + + ret = hid_parse(hdev); + if (ret) + return ret; + + ldev->hdev = hdev; + mutex_init(&ldev->lock); + + for (i = 0; !ldev->config && i < ARRAY_SIZE(hidled_configs); i++) + if (hidled_configs[i].type == id->driver_data) + ldev->config = &hidled_configs[i]; + + if (!ldev->config) + return -EINVAL; + + if (ldev->config->init) { + ret = ldev->config->init(ldev); + if (ret) + return ret; + } + + ldev->rgb = devm_kcalloc(&hdev->dev, ldev->config->num_leds, + sizeof(struct hidled_rgb), GFP_KERNEL); + if (!ldev->rgb) + return -ENOMEM; + + ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW); + if (ret) + return ret; + + minor = ((struct hidraw *) hdev->hidraw)->minor; + + for (i = 0; i < ldev->config->num_leds; i++) { + ldev->rgb[i].ldev = ldev; + ldev->rgb[i].num = i; + ret = hidled_init_rgb(&ldev->rgb[i], minor); + if (ret) { + hid_hw_stop(hdev); + return ret; + } + } + + hid_info(hdev, "%s initialized\n", ldev->config->name); + + return 0; +} + +static const struct hid_device_id hidled_table[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_RISO_KAGAKU, + USB_DEVICE_ID_RI_KA_WEBMAIL), .driver_data = RISO_KAGAKU }, + { HID_USB_DEVICE(USB_VENDOR_ID_DREAM_CHEEKY, + USB_DEVICE_ID_DREAM_CHEEKY_WN), .driver_data = DREAM_CHEEKY }, + { HID_USB_DEVICE(USB_VENDOR_ID_DREAM_CHEEKY, + USB_DEVICE_ID_DREAM_CHEEKY_FA), .driver_data = DREAM_CHEEKY }, + { HID_USB_DEVICE(USB_VENDOR_ID_THINGM, + USB_DEVICE_ID_BLINK1), .driver_data = THINGM }, + { HID_USB_DEVICE(USB_VENDOR_ID_DELCOM, + USB_DEVICE_ID_DELCOM_VISUAL_IND), .driver_data = DELCOM }, + { HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP, + USB_DEVICE_ID_LUXAFOR), .driver_data = LUXAFOR }, + { } +}; +MODULE_DEVICE_TABLE(hid, hidled_table); + +static struct hid_driver hidled_driver = { + .name = "hid-led", + .probe = hidled_probe, + .id_table = hidled_table, +}; + +module_hid_driver(hidled_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Heiner Kallweit "); +MODULE_DESCRIPTION("Simple USB RGB LED driver"); -- cgit v1.3.1