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, 79 insertions, 0 deletions

diff --git a/drivers/phy/freescale/Kconfig b/drivers/phy/freescale/Kconfig
new file mode 100644
index 000000000..7557b624b
--- /dev/null
+++ b/drivers/phy/freescale/Kconfig
@@ -0,0 +1,79 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+if (ARCH_MXC && ARM64) || COMPILE_TEST
+
+config PHY_FSL_IMX8MQ_USB
+	tristate "Freescale i.MX8M USB3 PHY"
+	depends on OF && HAS_IOMEM
+	depends on TYPEC || TYPEC=n
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	default ARCH_MXC && ARM64
+
+config PHY_MIXEL_LVDS_PHY
+	tristate "Mixel LVDS PHY support"
+	depends on OF
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	help
+	  Enable this to add support for the Mixel LVDS PHY as found
+	  on NXP's i.MX8qm SoC.
+
+config PHY_MIXEL_MIPI_DPHY
+	tristate "Mixel MIPI DSI PHY support"
+	depends on OF && HAS_IOMEM
+	select GENERIC_PHY
+	select GENERIC_PHY_MIPI_DPHY
+	select REGMAP_MMIO
+	help
+	  Enable this to add support for the Mixel DSI PHY as found
+	  on NXP's i.MX8 family of SOCs.
+
+config PHY_FSL_IMX8M_PCIE
+	tristate "Freescale i.MX8M PCIE PHY"
+	depends on OF && HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Enable this to add support for the PCIE PHY as found on
+	  i.MX8M family of SOCs.
+
+config PHY_FSL_IMX8QM_HSIO
+	tristate "Freescale i.MX8QM HSIO PHY"
+	depends on OF && HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Enable this to add support for the HSIO PHY as found on
+	  i.MX8QM family of SOCs.
+
+config PHY_FSL_SAMSUNG_HDMI_PHY
+	tristate "Samsung HDMI PHY support"
+	depends on OF && HAS_IOMEM && COMMON_CLK
+	help
+	  Enable this to add support for the Samsung HDMI PHY in i.MX8MP.
+endif
+
+config PHY_FSL_LYNX_CORE
+	tristate
+
+config PHY_FSL_LYNX_10G
+	tristate "Freescale Layerscape Lynx 10G SerDes PHY support"
+	depends on OF
+	depends on ARCH_LAYERSCAPE || COMPILE_TEST
+	select FSL_GUTS
+	select GENERIC_PHY
+	select PHY_FSL_LYNX_CORE
+	help
+	  Enable this to add support for the Lynx 10G SerDes PHY as found on
+	  NXP's Layerscape platform such as LS1088A or LS1028A.
+
+config PHY_FSL_LYNX_28G
+	tristate "Freescale Layerscape Lynx 28G SerDes PHY support"
+	depends on OF
+	depends on ARCH_LAYERSCAPE || COMPILE_TEST
+	select GENERIC_PHY
+	select PHY_FSL_LYNX_CORE
+	help
+	  Enable this to add support for the Lynx SerDes 28G PHY as
+	  found on NXP's Layerscape platforms such as LX2160A.
+	  Used to change the protocol running on SerDes lanes at runtime.
+	  Only useful for a restricted set of Ethernet protocols.