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, 452 insertions, 0 deletions

diff --git a/drivers/bluetooth/btintel.h b/drivers/bluetooth/btintel.h
new file mode 100644
index 000000000..966ec1b02
--- /dev/null
+++ b/drivers/bluetooth/btintel.h
@@ -0,0 +1,452 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *
+ *  Bluetooth support for Intel devices
+ *
+ *  Copyright (C) 2015  Intel Corporation
+ */
+
+/* List of tlv type */
+enum {
+	INTEL_TLV_CNVI_TOP = 0x10,
+	INTEL_TLV_CNVR_TOP,
+	INTEL_TLV_CNVI_BT,
+	INTEL_TLV_CNVR_BT,
+	INTEL_TLV_CNVI_OTP,
+	INTEL_TLV_CNVR_OTP,
+	INTEL_TLV_DEV_REV_ID,
+	INTEL_TLV_USB_VENDOR_ID,
+	INTEL_TLV_USB_PRODUCT_ID,
+	INTEL_TLV_PCIE_VENDOR_ID,
+	INTEL_TLV_PCIE_DEVICE_ID,
+	INTEL_TLV_PCIE_SUBSYSTEM_ID,
+	INTEL_TLV_IMAGE_TYPE,
+	INTEL_TLV_TIME_STAMP,
+	INTEL_TLV_BUILD_TYPE,
+	INTEL_TLV_BUILD_NUM,
+	INTEL_TLV_FW_BUILD_PRODUCT,
+	INTEL_TLV_FW_BUILD_HW,
+	INTEL_TLV_FW_STEP,
+	INTEL_TLV_BT_SPEC,
+	INTEL_TLV_MFG_NAME,
+	INTEL_TLV_HCI_REV,
+	INTEL_TLV_LMP_SUBVER,
+	INTEL_TLV_OTP_PATCH_VER,
+	INTEL_TLV_SECURE_BOOT,
+	INTEL_TLV_KEY_FROM_HDR,
+	INTEL_TLV_OTP_LOCK,
+	INTEL_TLV_API_LOCK,
+	INTEL_TLV_DEBUG_LOCK,
+	INTEL_TLV_MIN_FW,
+	INTEL_TLV_LIMITED_CCE,
+	INTEL_TLV_SBE_TYPE,
+	INTEL_TLV_OTP_BDADDR,
+	INTEL_TLV_UNLOCKED_STATE,
+	INTEL_TLV_GIT_SHA1,
+	INTEL_TLV_FW_ID = 0x50
+};
+
+struct intel_tlv {
+	u8 type;
+	u8 len;
+	u8 val[];
+} __packed;
+
+#define BTINTEL_HCI_OP_RESET	0xfc01
+#define BTINTEL_HCI_OP_DEBUG	0xfcd9
+
+#define BTINTEL_CNVI_BLAZARI		0x900	/* BlazarI - Lunar Lake */
+#define BTINTEL_CNVI_BLAZARIW		0x901	/* BlazarIW - Wildcat Lake */
+#define BTINTEL_CNVI_GAP		0x910	/* Gale Peak2 - Meteor Lake */
+#define BTINTEL_CNVI_BLAZARU		0x930	/* BlazarU - Meteor Lake */
+#define BTINTEL_CNVI_SCP		0xA00	/* Scorpius Peak - Panther Lake */
+#define BTINTEL_CNVI_SCP2		0xA10	/* Scorpius Peak2 - Nova Lake */
+#define BTINTEL_CNVI_SCP2F		0xA20	/* Scorpius Peak2F - Nova Lake */
+
+/* CNVR */
+#define BTINTEL_CNVR_FMP2		0x910
+#define BTINTEL_CNVR_WHP2		0xA10	/* Whale Peak2 - Panther Lake */
+
+#define BTINTEL_IMG_BOOTLOADER		0x01	/* Bootloader image */
+#define BTINTEL_IMG_IML			0x02	/* Intermediate image */
+#define BTINTEL_IMG_OP			0x03	/* Operational image */
+
+#define BTINTEL_FWID_MAXLEN 64
+
+/* CNVi Hardware variant */
+#define BTINTEL_HWID_GAP	0x1c	/* Gale Peak2 - Meteor Lake */
+#define BTINTEL_HWID_BZRI	0x1e	/* BlazarI - Lunar Lake */
+#define BTINTEL_HWID_BZRU	0x1d	/* BlazarU - Meteor Lake */
+#define BTINTEL_HWID_SCP	0x1f	/* Scorpius Peak - Panther Lake */
+#define BTINTEL_HWID_SCP2	0x20	/* Scorpius Peak2 - Nova Lake */
+#define BTINTEL_HWID_SCP2F	0x21	/* Scorpius Peak2-F - Nova Lake */
+#define BTINTEL_HWID_BZRIW	0x22	/* BlazarIW - Wildcat Lake */
+
+extern const guid_t btintel_guid_dsm;
+
+struct intel_version_tlv {
+	u32	cnvi_top;
+	u32	cnvr_top;
+	u32	cnvi_bt;
+	u32	cnvr_bt;
+	u16	dev_rev_id;
+	u8	img_type;
+	u16	timestamp;
+	u8	build_type;
+	u32	build_num;
+	u8	secure_boot;
+	u8	otp_lock;
+	u8	api_lock;
+	u8	debug_lock;
+	u8	min_fw_build_nn;
+	u8	min_fw_build_cw;
+	u8	min_fw_build_yy;
+	u8	limited_cce;
+	u8	sbe_type;
+	u32	git_sha1;
+	u8	fw_id[BTINTEL_FWID_MAXLEN];
+	bdaddr_t otp_bd_addr;
+};
+
+struct intel_version {
+	u8 status;
+	u8 hw_platform;
+	u8 hw_variant;
+	u8 hw_revision;
+	u8 fw_variant;
+	u8 fw_revision;
+	u8 fw_build_num;
+	u8 fw_build_ww;
+	u8 fw_build_yy;
+	u8 fw_patch_num;
+} __packed;
+
+struct intel_boot_params {
+	__u8     status;
+	__u8     otp_format;
+	__u8     otp_content;
+	__u8     otp_patch;
+	__le16   dev_revid;
+	__u8     secure_boot;
+	__u8     key_from_hdr;
+	__u8     key_type;
+	__u8     otp_lock;
+	__u8     api_lock;
+	__u8     debug_lock;
+	bdaddr_t otp_bdaddr;
+	__u8     min_fw_build_nn;
+	__u8     min_fw_build_cw;
+	__u8     min_fw_build_yy;
+	__u8     limited_cce;
+	__u8     unlocked_state;
+} __packed;
+
+struct intel_bootup {
+	__u8     zero;
+	__u8     num_cmds;
+	__u8     source;
+	__u8     reset_type;
+	__u8     reset_reason;
+	__u8     ddc_status;
+} __packed;
+
+struct intel_secure_send_result {
+	__u8     result;
+	__le16   opcode;
+	__u8     status;
+} __packed;
+
+struct intel_reset {
+	__u8     reset_type;
+	__u8     patch_enable;
+	__u8     ddc_reload;
+	__u8     boot_option;
+	__le32   boot_param;
+} __packed;
+
+struct intel_debug_features {
+	__u8    page1[16];
+} __packed;
+
+struct intel_offload_use_cases {
+	__u8	status;
+	__u8	preset[8];
+} __packed;
+
+#define INTEL_OP_PPAG_CMD		0xFE0B
+struct hci_ppag_enable_cmd {
+	__le32	ppag_enable_flags;
+} __packed;
+
+#define INTEL_TLV_TYPE_ID		0x01
+
+#define INTEL_TLV_SYSTEM_EXCEPTION	0x00
+#define INTEL_TLV_FATAL_EXCEPTION	0x01
+#define INTEL_TLV_DEBUG_EXCEPTION	0x02
+#define INTEL_TLV_TEST_EXCEPTION	0xDE
+
+struct btintel_cp_ddc_write {
+	u8	len;
+	__le16	id;
+	u8	data[];
+} __packed;
+
+/* Bluetooth SAR feature (BRDS), Revision 1 */
+struct btintel_sar_inc_pwr {
+	u8	revision;
+	u32	bt_sar_bios; /* Mode of SAR control to be used, 1:enabled in bios */
+	u32	inc_power_mode;  /* Increased power mode */
+	u8	sar_2400_chain_a; /* Sar power restriction LB */
+	u8	br;
+	u8	edr2;
+	u8	edr3;
+	u8	le;
+	u8	le_2mhz;
+	u8	le_lr;
+};
+
+/* Bluetooth SAR feature (BRDS), Revision 2 - per-chain sub-band power limits */
+struct btintel_sar_band_limits {
+	u8	subband_2g4;
+	u8	subband_5g2;
+	u8	subband_5g8_5g9;
+	u8	subband_6g1;
+	u8	subband_6g3;
+};
+
+struct btintel_sar_rev2 {
+	u8	revision;
+	u32	bt_sar_bios;    /* 1: BIOS-managed SAR enabled */
+	u32	inc_power_mode; /* 0: supported, 1: disabled */
+	struct btintel_sar_band_limits chain_a;
+	struct btintel_sar_band_limits chain_b;
+};
+
+#define INTEL_HW_PLATFORM(cnvx_bt)	((u8)(((cnvx_bt) & 0x0000ff00) >> 8))
+#define INTEL_HW_VARIANT(cnvx_bt)	((u8)(((cnvx_bt) & 0x003f0000) >> 16))
+#define INTEL_CNVX_TOP_TYPE(cnvx_top)	((cnvx_top) & 0x00000fff)
+#define INTEL_CNVX_TOP_STEP(cnvx_top)	(((cnvx_top) & 0x0f000000) >> 24)
+#define INTEL_CNVX_TOP_PACK_SWAB(t, s)	__swab16(((__u16)(((t) << 4) | (s))))
+
+enum {
+	INTEL_BOOTLOADER,
+	INTEL_DOWNLOADING,
+	INTEL_FIRMWARE_LOADED,
+	INTEL_FIRMWARE_FAILED,
+	INTEL_BOOTING,
+	INTEL_BROKEN_INITIAL_NCMD,
+	INTEL_BROKEN_SHUTDOWN_LED,
+	INTEL_ROM_LEGACY,
+	INTEL_ROM_LEGACY_NO_WBS_SUPPORT,
+	INTEL_ACPI_RESET_ACTIVE,
+	INTEL_WAIT_FOR_D0,
+
+	__INTEL_NUM_FLAGS,
+};
+
+struct btintel_data {
+	DECLARE_BITMAP(flags, __INTEL_NUM_FLAGS);
+	int (*acpi_reset_method)(struct hci_dev *hdev);
+};
+
+#define btintel_set_flag(hdev, nr)					\
+	do {								\
+		struct btintel_data *intel = hci_get_priv((hdev));	\
+		set_bit((nr), intel->flags);				\
+	} while (0)
+
+#define btintel_clear_flag(hdev, nr)					\
+	do {								\
+		struct btintel_data *intel = hci_get_priv((hdev));	\
+		clear_bit((nr), intel->flags);				\
+	} while (0)
+
+#define btintel_wake_up_flag(hdev, nr)					\
+	do {								\
+		struct btintel_data *intel = hci_get_priv((hdev));	\
+		wake_up_bit(intel->flags, (nr));			\
+	} while (0)
+
+#define btintel_get_flag(hdev)						\
+	(((struct btintel_data *)hci_get_priv(hdev))->flags)
+
+#define btintel_test_flag(hdev, nr)	test_bit((nr), btintel_get_flag(hdev))
+#define btintel_test_and_clear_flag(hdev, nr) test_and_clear_bit((nr), btintel_get_flag(hdev))
+#define btintel_wait_on_flag_timeout(hdev, nr, m, to)			\
+		wait_on_bit_timeout(btintel_get_flag(hdev), (nr), m, to)
+
+#if IS_ENABLED(CONFIG_BT_INTEL) || IS_ENABLED(CONFIG_BT_INTEL_PCIE)
+
+int btintel_check_bdaddr(struct hci_dev *hdev);
+int btintel_enter_mfg(struct hci_dev *hdev);
+int btintel_exit_mfg(struct hci_dev *hdev, bool reset, bool patched);
+int btintel_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr);
+int btintel_set_diag(struct hci_dev *hdev, bool enable);
+
+int btintel_version_info(struct hci_dev *hdev, struct intel_version *ver);
+int btintel_load_ddc_config(struct hci_dev *hdev, const char *ddc_name);
+int btintel_set_event_mask_mfg(struct hci_dev *hdev, bool debug);
+int btintel_read_version(struct hci_dev *hdev, struct intel_version *ver);
+struct regmap *btintel_regmap_init(struct hci_dev *hdev, u16 opcode_read,
+				   u16 opcode_write);
+int btintel_send_intel_reset(struct hci_dev *hdev, u32 boot_param);
+int btintel_read_boot_params(struct hci_dev *hdev,
+			     struct intel_boot_params *params);
+int btintel_download_firmware(struct hci_dev *dev, struct intel_version *ver,
+			      const struct firmware *fw, u32 *boot_param);
+int btintel_configure_setup(struct hci_dev *hdev, const char *driver_name);
+int btintel_recv_event(struct hci_dev *hdev, struct sk_buff *skb);
+void btintel_bootup(struct hci_dev *hdev, const void *ptr, unsigned int len);
+void btintel_secure_send_result(struct hci_dev *hdev,
+				const void *ptr, unsigned int len);
+int btintel_set_quality_report(struct hci_dev *hdev, bool enable);
+int btintel_version_info_tlv(struct hci_dev *hdev,
+			     struct intel_version_tlv *version);
+int btintel_parse_version_tlv(struct hci_dev *hdev,
+			      struct intel_version_tlv *version,
+			      struct sk_buff *skb);
+void btintel_set_msft_opcode(struct hci_dev *hdev, u8 hw_variant);
+int btintel_bootloader_setup_tlv(struct hci_dev *hdev,
+				 struct intel_version_tlv *ver);
+int btintel_shutdown_combined(struct hci_dev *hdev);
+void btintel_hw_error(struct hci_dev *hdev, u8 code);
+void btintel_print_fseq_info(struct hci_dev *hdev);
+int btintel_acpi_reset_method(struct hci_dev *hdev);
+#else
+
+static inline int btintel_check_bdaddr(struct hci_dev *hdev)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int btintel_enter_mfg(struct hci_dev *hdev)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int btintel_exit_mfg(struct hci_dev *hdev, bool reset, bool patched)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int btintel_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int btintel_set_diag(struct hci_dev *hdev, bool enable)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int btintel_version_info(struct hci_dev *hdev,
+				       struct intel_version *ver)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int btintel_load_ddc_config(struct hci_dev *hdev,
+					  const char *ddc_name)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int btintel_set_event_mask_mfg(struct hci_dev *hdev, bool debug)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int btintel_read_version(struct hci_dev *hdev,
+				       struct intel_version *ver)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline struct regmap *btintel_regmap_init(struct hci_dev *hdev,
+						 u16 opcode_read,
+						 u16 opcode_write)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+static inline int btintel_send_intel_reset(struct hci_dev *hdev,
+					   u32 reset_param)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int btintel_read_boot_params(struct hci_dev *hdev,
+					   struct intel_boot_params *params)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int btintel_download_firmware(struct hci_dev *dev,
+					    const struct firmware *fw,
+					    u32 *boot_param)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int btintel_configure_setup(struct hci_dev *hdev,
+					  const char *driver_name)
+{
+	return -ENODEV;
+}
+
+static inline void btintel_bootup(struct hci_dev *hdev,
+				  const void *ptr, unsigned int len)
+{
+}
+
+static inline void btintel_secure_send_result(struct hci_dev *hdev,
+				const void *ptr, unsigned int len)
+{
+}
+
+static inline int btintel_set_quality_report(struct hci_dev *hdev, bool enable)
+{
+	return -ENODEV;
+}
+
+static inline int btintel_version_info_tlv(struct hci_dev *hdev,
+					   struct intel_version_tlv *version)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int btintel_parse_version_tlv(struct hci_dev *hdev,
+					    struct intel_version_tlv *version,
+					    struct sk_buff *skb)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void btintel_set_msft_opcode(struct hci_dev *hdev, u8 hw_variant)
+
+{
+}
+
+static inline int btintel_bootloader_setup_tlv(struct hci_dev *hdev,
+					       struct intel_version_tlv *ver)
+{
+	return -ENODEV;
+}
+
+static inline int btintel_shutdown_combined(struct hci_dev *hdev)
+{
+	return -ENODEV;
+}
+
+static inline void btintel_hw_error(struct hci_dev *hdev, u8 code)
+{
+}
+
+static inline void btintel_print_fseq_info(struct hci_dev *hdev)
+{
+}
+static inline int btintel_acpi_reset_method(struct hci_dev *hdev)
+{
+	return -ENODEV;
+}
+#endif