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, 173 insertions, 0 deletions

diff --git a/drivers/usb/serial/usb-serial-simple.c b/drivers/usb/serial/usb-serial-simple.c
new file mode 100644
index 000000000..a0afaf254
--- /dev/null
+++ b/drivers/usb/serial/usb-serial-simple.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * USB Serial "Simple" driver
+ *
+ * Copyright (C) 2001-2006,2008,2013 Greg Kroah-Hartman <greg@kroah.com>
+ * Copyright (C) 2005 Arthur Huillet (ahuillet@users.sf.net)
+ * Copyright (C) 2005 Thomas Hergenhahn <thomas.hergenhahn@suse.de>
+ * Copyright (C) 2009 Outpost Embedded, LLC
+ * Copyright (C) 2010 Zilogic Systems <code@zilogic.com>
+ * Copyright (C) 2013 Wei Shuai <cpuwolf@gmail.com>
+ * Copyright (C) 2013 Linux Foundation
+ */
+
+#include <linux/kernel.h>
+#include <linux/tty.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+
+#define DEVICE_N(vendor, IDS, nport)				\
+static const struct usb_device_id vendor##_id_table[] = {	\
+	IDS(),							\
+	{ },							\
+};								\
+static struct usb_serial_driver vendor##_device = {		\
+	.driver = {						\
+		.name =		#vendor,			\
+	},							\
+	.id_table =		vendor##_id_table,		\
+	.num_ports =		nport,				\
+};
+
+#define DEVICE(vendor, IDS)	DEVICE_N(vendor, IDS, 1)
+
+/* Medtronic CareLink USB driver */
+#define CARELINK_IDS()			\
+	{ USB_DEVICE(0x0a21, 0x8001) }	/* MMT-7305WW */
+DEVICE(carelink, CARELINK_IDS);
+
+/* Infineon Flashloader driver */
+#define FLASHLOADER_IDS()		\
+	{ USB_DEVICE_INTERFACE_CLASS(0x058b, 0x0041, USB_CLASS_CDC_DATA) }, \
+	{ USB_DEVICE(0x8087, 0x0716) }, \
+	{ USB_DEVICE(0x8087, 0x0801) }
+DEVICE(flashloader, FLASHLOADER_IDS);
+
+/* Funsoft Serial USB driver */
+#define FUNSOFT_IDS()			\
+	{ USB_DEVICE(0x1404, 0xcddc) }
+DEVICE(funsoft, FUNSOFT_IDS);
+
+/* Google Serial USB SubClass */
+#define GOOGLE_IDS()						\
+	{ USB_VENDOR_AND_INTERFACE_INFO(0x18d1,			\
+					USB_CLASS_VENDOR_SPEC,	\
+					0x50,			\
+					0x01) }
+DEVICE(google, GOOGLE_IDS);
+
+/* HP4x (48/49) Generic Serial driver */
+#define HP4X_IDS()			\
+	{ USB_DEVICE(0x03f0, 0x0121) }
+DEVICE(hp4x, HP4X_IDS);
+
+/* KAUFMANN RKS+CAN VCP */
+#define KAUFMANN_IDS()			\
+	{ USB_DEVICE(0x16d0, 0x0870) }
+DEVICE(kaufmann, KAUFMANN_IDS);
+
+/* Libtransistor USB console */
+#define LIBTRANSISTOR_IDS()			\
+	{ USB_DEVICE(0x1209, 0x8b00) }
+DEVICE(libtransistor, LIBTRANSISTOR_IDS);
+
+/* Motorola USB Phone driver */
+#define MOTO_IDS()			\
+	{ USB_DEVICE(0x05c6, 0x3197) },	/* unknown Motorola phone */	\
+	{ USB_DEVICE(0x0c44, 0x0022) },	/* unknown Motorola phone */	\
+	{ USB_DEVICE(0x22b8, 0x2a64) },	/* Motorola KRZR K1m */		\
+	{ USB_DEVICE(0x22b8, 0x2c84) },	/* Motorola VE240 phone */	\
+	{ USB_DEVICE(0x22b8, 0x2c64) }	/* Motorola V950 phone */
+DEVICE(moto_modem, MOTO_IDS);
+
+/* Motorola Tetra driver */
+#define MOTOROLA_TETRA_IDS()			\
+	{ USB_DEVICE(0x0cad, 0x9011) },	/* Motorola Solutions TETRA PEI */ \
+	{ USB_DEVICE(0x0cad, 0x9012) },	/* MTP6550 */ \
+	{ USB_DEVICE(0x0cad, 0x9013) },	/* MTP3xxx */ \
+	{ USB_DEVICE(0x0cad, 0x9015) },	/* MTP85xx */ \
+	{ USB_DEVICE(0x0cad, 0x9016) }	/* TPG2200 */
+DEVICE(motorola_tetra, MOTOROLA_TETRA_IDS);
+
+/* Nokia mobile phone driver */
+#define NOKIA_IDS()			\
+	{ USB_DEVICE(0x0421, 0x069a) }	/* Nokia 130 (RM-1035) */
+DEVICE(nokia, NOKIA_IDS);
+
+/* Novatel Wireless GPS driver */
+#define NOVATEL_IDS()			\
+	{ USB_DEVICE(0x09d7, 0x0100) }	/* NovAtel FlexPack GPS */
+DEVICE_N(novatel_gps, NOVATEL_IDS, 3);
+
+/* OWON electronic test and measurement equipment driver */
+#define OWON_IDS()			\
+	{ USB_DEVICE(0x5345, 0x1234) } /* HDS200 oscilloscopes and others */
+DEVICE(owon, OWON_IDS);
+
+/* Siemens USB/MPI adapter */
+#define SIEMENS_IDS()			\
+	{ USB_DEVICE(0x908, 0x0004) }
+DEVICE(siemens_mpi, SIEMENS_IDS);
+
+/* Suunto ANT+ USB Driver */
+#define SUUNTO_IDS()			\
+	{ USB_DEVICE(0x0fcf, 0x1008) },	\
+	{ USB_DEVICE(0x0fcf, 0x1009) } /* Dynastream ANT USB-m Stick */
+DEVICE(suunto, SUUNTO_IDS);
+
+/* ViVOpay USB Serial Driver */
+#define VIVOPAY_IDS()			\
+	{ USB_DEVICE(0x1d5f, 0x1004) }	/* ViVOpay 8800 */
+DEVICE(vivopay, VIVOPAY_IDS);
+
+/* ZIO Motherboard USB driver */
+#define ZIO_IDS()			\
+	{ USB_DEVICE(0x1CBE, 0x0103) }
+DEVICE(zio, ZIO_IDS);
+
+/* All of the above structures mushed into two lists */
+static struct usb_serial_driver * const serial_drivers[] = {
+	&carelink_device,
+	&flashloader_device,
+	&funsoft_device,
+	&google_device,
+	&hp4x_device,
+	&kaufmann_device,
+	&libtransistor_device,
+	&moto_modem_device,
+	&motorola_tetra_device,
+	&nokia_device,
+	&novatel_gps_device,
+	&owon_device,
+	&siemens_mpi_device,
+	&suunto_device,
+	&vivopay_device,
+	&zio_device,
+	NULL
+};
+
+static const struct usb_device_id id_table[] = {
+	CARELINK_IDS(),
+	FLASHLOADER_IDS(),
+	FUNSOFT_IDS(),
+	GOOGLE_IDS(),
+	HP4X_IDS(),
+	KAUFMANN_IDS(),
+	LIBTRANSISTOR_IDS(),
+	MOTO_IDS(),
+	MOTOROLA_TETRA_IDS(),
+	NOKIA_IDS(),
+	NOVATEL_IDS(),
+	OWON_IDS(),
+	SIEMENS_IDS(),
+	SUUNTO_IDS(),
+	VIVOPAY_IDS(),
+	ZIO_IDS(),
+	{ },
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+module_usb_serial_driver(serial_drivers, id_table);
+MODULE_DESCRIPTION("USB Serial 'Simple' driver");
+MODULE_LICENSE("GPL v2");