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, 100 insertions, 0 deletions

diff --git a/drivers/phy/mediatek/Kconfig b/drivers/phy/mediatek/Kconfig
new file mode 100644
index 000000000..ba6461350
--- /dev/null
+++ b/drivers/phy/mediatek/Kconfig
@@ -0,0 +1,100 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Mediatek devices
+#
+config PHY_MTK_PCIE
+	tristate "MediaTek PCIe-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Say 'Y' here to add support for MediaTek PCIe PHY driver.
+	  This driver create the basic PHY instance and provides initialize
+	  callback for PCIe GEN3 port, it supports software efuse
+	  initialization.
+
+config PHY_MTK_XFI_TPHY
+	tristate "MediaTek 10GE SerDes XFI T-PHY driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Say 'Y' here to add support for MediaTek XFI T-PHY driver.
+	  The driver provides access to the Ethernet SerDes T-PHY supporting
+	  1GE and 2.5GE modes via the LynxI PCS, and 5GE and 10GE modes
+	  via the USXGMII PCS found in MediaTek SoCs with 10G Ethernet.
+
+config PHY_MTK_TPHY
+	tristate "MediaTek T-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF && OF_ADDRESS
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Say 'Y' here to add support for MediaTek T-PHY driver,
+	  it supports multiple usb2.0, usb3.0 ports, PCIe and
+	  SATA, and meanwhile supports two version T-PHY which have
+	  different banks layout, the T-PHY with shared banks between
+	  multi-ports is first version, otherwise is second version,
+	  so you can easily distinguish them by banks layout.
+
+config PHY_MTK_UFS
+	tristate "MediaTek UFS M-PHY driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Support for UFS M-PHY on MediaTek chipsets.
+	  Enable this to provide vendor-specific probing,
+	  initialization, power on and power off flow of
+	  specified M-PHYs.
+
+config PHY_MTK_XSPHY
+	tristate "MediaTek XS-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF && OF_ADDRESS
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Enable this to support the SuperSpeedPlus XS-PHY transceiver for
+	  USB3.1 GEN2 controllers on MediaTek chips. The driver supports
+	  multiple USB2.0, USB3.1 GEN2 ports.
+
+config PHY_MTK_HDMI
+	tristate "MediaTek HDMI-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on COMMON_CLK
+	depends on OF
+	depends on REGULATOR
+	select GENERIC_PHY
+	help
+	  Support HDMI PHY for Mediatek SoCs.
+
+config PHY_MTK_MIPI_CSI_0_5
+	tristate "MediaTek MIPI CSI CD-PHY v0.5 Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Enable this to support the MIPI CSI CD-PHY receiver version 0.5.
+	  The driver supports multiple CSI cdphy ports simultaneously.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called phy-mtk-mipi-csi-0-5.
+
+config PHY_MTK_MIPI_DSI
+	tristate "MediaTek MIPI-DSI Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on COMMON_CLK
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Support MIPI DSI for Mediatek SoCs.
+
+config PHY_MTK_DP
+	tristate "MediaTek DP-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Support DisplayPort PHY for MediaTek SoCs.