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, 57 insertions, 0 deletions

diff --git a/sound/hda/controllers/Kconfig b/sound/hda/controllers/Kconfig
new file mode 100644
index 000000000..26ca69b09
--- /dev/null
+++ b/sound/hda/controllers/Kconfig
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config SND_HDA_INTEL
+	tristate "HD Audio PCI"
+	depends on PCI
+	select SND_HDA
+	select SND_INTEL_DSP_CONFIG
+	help
+	  Say Y here to include support for Intel "High Definition
+	  Audio" (Azalia) and its compatible devices.
+
+	  This option enables the HD-audio controller.  Don't forget
+	  to choose the appropriate HD-audio codec options.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-hda-intel.
+
+config SND_HDA_TEGRA
+	tristate "NVIDIA Tegra HD Audio"
+	depends on ARCH_TEGRA
+	select SND_HDA
+	select SND_HDA_ALIGNED_MMIO
+	help
+	  Say Y here to support the HDA controller present in NVIDIA
+	  Tegra SoCs
+
+	  This options enables support for the HD Audio controller
+	  present in some NVIDIA Tegra SoCs, used to communicate audio
+	  to the HDMI output.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-hda-tegra.
+
+config SND_HDA_CIX_IPBLOQ
+	tristate "CIX IPBLOQ HD Audio"
+	depends on ARCH_CIX || COMPILE_TEST
+	depends on ARCH_DMA_ADDR_T_64BIT
+	select SND_HDA
+	select SND_HDA_ALIGNED_MMIO
+	help
+	  Say Y here to support the HDA controller present in CIX SoCs
+
+	  This options enables support for the HD Audio controller
+	  present in some CIX SoCs.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-hda-cix-ipbloq.
+
+config SND_HDA_ACPI
+	tristate "HD Audio ACPI"
+	depends on ACPI
+	select SND_HDA
+	help
+	  Say Y here to include support for Azalia-compatible HDA controllers
+	  which are advertised via ACPI objects.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-hda-acpi.