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, 124 insertions, 0 deletions

diff --git a/drivers/message/fusion/Kconfig b/drivers/message/fusion/Kconfig
new file mode 100644
index 000000000..88a6e506a
--- /dev/null
+++ b/drivers/message/fusion/Kconfig
@@ -0,0 +1,124 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menuconfig FUSION
+	bool "Fusion MPT device support"
+	depends on PCI && HAS_IOPORT
+	help
+	Say Y here to get to see options for Fusion Message
+	Passing Technology (MPT) drivers.
+	This option alone does not add any kernel code.
+
+	If you say N, all options in this submenu will be skipped and disabled.
+
+if FUSION
+
+config FUSION_SPI
+	tristate "Fusion MPT ScsiHost drivers for SPI"
+	depends on PCI && SCSI
+	select SCSI_SPI_ATTRS
+	help
+	  SCSI HOST support for a parallel SCSI host adapters.
+
+	  List of supported controllers:
+
+	  LSI53C1020
+	  LSI53C1020A
+	  LSI53C1030
+	  LSI53C1035
+	  ATTO UL4D
+
+config FUSION_FC
+	tristate "Fusion MPT ScsiHost drivers for FC"
+	depends on PCI && SCSI
+	depends on SCSI_FC_ATTRS
+	help
+	  SCSI HOST support for a Fiber Channel host adapters.
+
+	  List of supported controllers:
+
+	  LSIFC909
+	  LSIFC919
+	  LSIFC919X
+	  LSIFC929
+	  LSIFC929X
+	  LSIFC929XL
+	  LSIFC949X
+	  LSIFC949E
+	  Brocade FC 410/420
+
+config FUSION_SAS
+	tristate "Fusion MPT ScsiHost drivers for SAS"
+	depends on PCI && SCSI
+	select SCSI_SAS_ATTRS
+	help
+	  SCSI HOST support for a SAS host adapters.
+
+	  List of supported controllers:
+
+	  LSISAS1064
+	  LSISAS1068
+	  LSISAS1064E
+	  LSISAS1068E
+	  LSISAS1078
+
+config FUSION_MAX_SGE
+	int "Maximum number of scatter gather entries (16 - 128)"
+	default "128"
+	range 16 128
+	help
+	  This option allows you to specify the maximum number of scatter-
+	  gather entries per I/O. The driver default is 128, which matches
+	  SCSI_MAX_PHYS_SEGMENTS. However, it may decreased down to 16.
+	  Decreasing this parameter will reduce memory requirements
+	  on a per controller instance.
+
+config FUSION_CTL
+	tristate "Fusion MPT misc device (ioctl) driver"
+	depends on FUSION_SPI || FUSION_FC || FUSION_SAS
+	help
+	  The Fusion MPT misc device driver provides specialized control
+	  of MPT adapters via system ioctl calls.  Use of ioctl calls to
+	  the MPT driver requires that you create and use a misc device
+	  node ala:
+	  mknod /dev/mptctl c 10 240
+
+	  One use of this ioctl interface is to perform an upgrade (reflash)
+	  of the MPT adapter firmware.  Refer to readme file(s) distributed
+	  with the Fusion MPT linux driver for additional details.
+
+	  If enabled by saying M to this, a driver named: mptctl
+	  will be compiled.
+
+	  If unsure whether you really want or need this, say N.
+
+config FUSION_LAN
+	tristate "Fusion MPT LAN driver"
+	depends on FUSION_FC && NET_FC
+	help
+	  This module supports LAN IP traffic over Fibre Channel port(s)
+	  on Fusion MPT compatible hardware (LSIFC9xx chips).
+	  The physical interface used is defined in RFC 2625.
+	  Please refer to that document for details.
+
+	  Installing this driver requires the knowledge to configure and
+	  activate a new network interface, "fc0", using standard Linux tools.
+
+	  If enabled by saying M to this, a driver named: mptlan
+	  will be compiled.
+
+	  If unsure whether you really want or need this, say N.
+
+config FUSION_LOGGING
+	bool "Fusion MPT logging facility"
+	help
+	  This turns on a logging facility that can be used to debug a number
+	  of Fusion MPT related problems.
+
+	  The debug level can be programmed on the fly via SysFS (hex values)
+
+	  echo [level] > /sys/class/scsi_host/host#/debug_level
+
+	  There are various debug levels that can be found in the source:
+	  file:drivers/message/fusion/mptdebug.h
+
+endif # FUSION