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, 92 insertions, 0 deletions

diff --git a/drivers/w1/masters/Kconfig b/drivers/w1/masters/Kconfig
new file mode 100644
index 000000000..e6049a75b
--- /dev/null
+++ b/drivers/w1/masters/Kconfig
@@ -0,0 +1,92 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# 1-wire bus master configuration
+#
+
+menu "1-wire Bus Masters"
+
+config W1_MASTER_AMD_AXI
+	tristate "AMD AXI 1-wire bus host"
+	help
+	  Say Y here is you want to support the AMD AXI 1-wire IP core.
+	  This driver makes use of the programmable logic IP to perform
+	  correctly timed 1 wire transactions without relying on GPIO timing
+	  through the kernel.
+
+	  This driver can also be built as a module.  If so, the module will be
+	  called amd_w1_axi.
+
+config W1_MASTER_MATROX
+	tristate "Matrox G400 transport layer for 1-wire"
+	depends on PCI
+	help
+	  Say Y here if you want to communicate with your 1-wire devices
+	  using Matrox's G400 GPIO pins.
+
+	  This support is also available as a module.  If so, the module
+	  will be called matrox_w1.
+
+config W1_MASTER_DS2490
+	tristate "DS2490 USB <-> W1 transport layer for 1-wire"
+  	depends on USB
+  	help
+	  Say Y here if you want to have a driver for DS2490 based USB <-> W1 bridges,
+	  for example DS9490*.
+
+  	  This support is also available as a module.  If so, the module
+	  will be called ds2490.
+
+config W1_MASTER_DS2482
+	tristate "Maxim DS2482 I2C to 1-Wire bridge"
+	depends on I2C
+	help
+	  If you say yes here you get support for the Maxim DS2482
+	  I2C to 1-Wire bridge.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called ds2482.
+
+config W1_MASTER_MXC
+	tristate "Freescale MXC 1-wire busmaster"
+	depends on ARCH_MXC || COMPILE_TEST
+	help
+	  Say Y here to enable MXC 1-wire host
+
+config W1_MASTER_GPIO
+	tristate "GPIO 1-wire busmaster"
+	depends on GPIOLIB || COMPILE_TEST
+	help
+	  Say Y here if you want to communicate with your 1-wire devices using
+	  GPIO pins. This driver uses the GPIO API to control the wire.
+
+	  This support is also available as a module.  If so, the module
+	  will be called w1-gpio.
+
+config HDQ_MASTER_OMAP
+	tristate "OMAP HDQ driver"
+	depends on ARCH_OMAP || COMPILE_TEST
+	help
+	  Say Y here if you want support for the 1-wire or HDQ Interface
+	  on an OMAP processor.
+
+config W1_MASTER_SGI
+	tristate "SGI ASIC driver"
+	help
+	  Say Y here if you want support for your 1-wire devices using
+	  SGI ASIC 1-Wire interface
+
+	  This support is also available as a module.  If so, the module
+	  will be called sgi_w1.
+
+config W1_MASTER_UART
+	tristate "UART 1-wire driver"
+	depends on SERIAL_DEV_BUS
+	help
+	  Say Y here if you want to communicate with your 1-wire devices using
+	  UART interface.
+
+	  This support is also available as a module.  If so, the module
+	  will be called w1-uart.
+
+endmenu
+