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, 73 insertions, 0 deletions

diff --git a/drivers/nfc/Kconfig b/drivers/nfc/Kconfig
new file mode 100644
index 000000000..288c6f1c6
--- /dev/null
+++ b/drivers/nfc/Kconfig
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Near Field Communication (NFC) devices
+#
+
+menu "Near Field Communication (NFC) devices"
+	depends on NFC
+
+config NFC_TRF7970A
+	tristate "Texas Instruments TRF7970a NFC driver"
+	depends on SPI && NFC_DIGITAL && GPIOLIB
+	help
+	  This option enables the NFC driver for Texas Instruments' TRF7970a
+	  device. Such device supports 5 different protocols: ISO14443A,
+	  ISO14443B, FeLiCa, ISO15693 and ISO18000-3.
+
+	  Say Y here to compile support for TRF7970a into the kernel or
+	  say M  to compile it as a module. The module will be called
+	  trf7970a.ko.
+
+config NFC_MEI_PHY
+	tristate "MEI bus NFC device support"
+	depends on INTEL_MEI && NFC_HCI
+	help
+	  This adds support to use an mei bus nfc device. Select this if you
+	  will use an HCI NFC driver for an NFC chip connected behind an
+	  Intel's Management Engine chip.
+
+	  If unsure, say N.
+
+config NFC_SIM
+	tristate "NFC hardware simulator driver"
+	depends on NFC_DIGITAL
+	help
+	  This driver declares two virtual NFC devices supporting NFC-DEP
+	  protocol. An LLCP connection can be established between them and
+	  all packets sent from one device is sent back to the other, acting as
+	  loopback devices.
+
+	  If unsure, say N.
+
+config NFC_PORT100
+	tristate "Sony NFC Port-100 Series USB device support"
+	depends on USB
+	depends on NFC_DIGITAL
+	help
+	  This adds support for Sony Port-100 chip based USB devices such as the
+	  RC-S380 dongle.
+
+	  If unsure, say N.
+
+config NFC_VIRTUAL_NCI
+	tristate "NCI device simulator driver"
+	depends on NFC_NCI
+	help
+	  NCI virtual device simulates a NCI device to the user.
+	  It can be used to validate the NCI module and applications.
+	  This driver supports communication between the virtual NCI device and
+	  module.
+
+	  If unsure, say N.
+
+source "drivers/nfc/fdp/Kconfig"
+source "drivers/nfc/pn544/Kconfig"
+source "drivers/nfc/pn533/Kconfig"
+source "drivers/nfc/microread/Kconfig"
+source "drivers/nfc/nfcmrvl/Kconfig"
+source "drivers/nfc/st21nfca/Kconfig"
+source "drivers/nfc/st-nci/Kconfig"
+source "drivers/nfc/nxp-nci/Kconfig"
+source "drivers/nfc/s3fwrn5/Kconfig"
+source "drivers/nfc/st95hf/Kconfig"
+endmenu