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, 177 insertions, 0 deletions

diff --git a/drivers/firewire/Kconfig b/drivers/firewire/Kconfig
new file mode 100644
index 000000000..b5abe00ac
--- /dev/null
+++ b/drivers/firewire/Kconfig
@@ -0,0 +1,177 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "IEEE 1394 (FireWire) support"
+	depends on PCI || COMPILE_TEST
+	# firewire-core does not depend on PCI but is
+	# not useful without PCI controller driver
+
+config FIREWIRE
+	tristate "FireWire driver stack"
+	select CRC_ITU_T
+	help
+	  This is the new-generation IEEE 1394 (FireWire) driver stack
+	  a.k.a. Juju, a new implementation designed for robustness and
+	  simplicity.
+	  See http://ieee1394.docs.kernel.org/en/latest/migration.html
+	  for information about migration from the older Linux 1394 stack
+	  to the new driver stack.
+
+	  To compile this driver as a module, say M here: the module will be
+	  called firewire-core.
+
+config FIREWIRE_KUNIT_UAPI_TEST
+	tristate "KUnit tests for layout of structure in UAPI" if !KUNIT_ALL_TESTS
+	depends on FIREWIRE && KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This builds the KUnit tests whether structures exposed to user
+	  space have expected layout.
+
+	  KUnit tests run during boot and output the results to the debug
+	  log in TAP format (https://testanything.org/). Only useful for
+	  kernel devs running KUnit test harness and are not for inclusion
+	  into a production build.
+
+	  For more information on KUnit and unit tests in general, refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+config FIREWIRE_KUNIT_DEVICE_ATTRIBUTE_TEST
+	tristate "KUnit tests for device attributes" if !KUNIT_ALL_TESTS
+	depends on FIREWIRE && KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This builds the KUnit tests for device attribute for node and
+	  unit.
+
+	  KUnit tests run during boot and output the results to the debug
+	  log in TAP format (https://testanything.org/). Only useful for
+	  kernel devs running KUnit test harness and are not for inclusion
+	  into a production build.
+
+	  For more information on KUnit and unit tests in general, refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+config FIREWIRE_KUNIT_PACKET_SERDES_TEST
+	tristate "KUnit tests for packet serialization/deserialization" if !KUNIT_ALL_TESTS
+	depends on FIREWIRE && KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This builds the KUnit tests for packet serialization and
+	  deserialization.
+
+	  KUnit tests run during boot and output the results to the debug
+	  log in TAP format (https://testanything.org/). Only useful for
+	  kernel devs running KUnit test harness and are not for inclusion
+	  into a production build.
+
+	  For more information on KUnit and unit tests in general, refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+config FIREWIRE_KUNIT_SELF_ID_SEQUENCE_HELPER_TEST
+	tristate "KUnit tests for helpers of self ID sequence" if !KUNIT_ALL_TESTS
+	depends on FIREWIRE && KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This builds the KUnit tests for helpers of self ID sequence.
+
+	  KUnit tests run during boot and output the results to the debug
+	  log in TAP format (https://testanything.org/). Only useful for
+	  kernel devs running KUnit test harness and are not for inclusion
+	  into a production build.
+
+	  For more information on KUnit and unit tests in general, refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+config FIREWIRE_KUNIT_NODE_TREE_TEST
+	tristate "KUnit tests for node tree" if !KUNIT_ALL_TESTS
+	depends on FIREWIRE && KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This builds the KUnit tests for node tree.
+
+	  KUnit tests run during boot and output the results to the debug
+	  log in TAP format (https://testanything.org/). Only useful for
+	  kernel devs running KUnit test harness and are not for inclusion
+	  into a production build.
+
+	  For more information on KUnit and unit tests in general, refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+config FIREWIRE_OHCI
+	tristate "OHCI-1394 controllers"
+	depends on PCI && FIREWIRE
+	help
+	  Enable this driver if you have a FireWire controller based
+	  on the OHCI specification.  For all practical purposes, this
+	  is the only chipset in use, so say Y here.
+
+	  To compile this driver as a module, say M here:  The module will be
+	  called firewire-ohci.
+
+config FIREWIRE_KUNIT_OHCI_SERDES_TEST
+	tristate "KUnit tests for serialization/deserialization of data in buffers/registers" if !KUNIT_ALL_TESTS
+	depends on FIREWIRE && KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This builds the KUnit tests to check serialization and deserialization
+	  of data in buffers and registers defined in 1394 OHCI specification.
+
+	  KUnit tests run during boot and output the results to the debug
+	  log in TAP format (https://testanything.org/). Only useful for
+	  kernel devs running KUnit test harness and are not for inclusion
+	  into a production build.
+
+	  For more information on KUnit and unit tests in general, refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+config FIREWIRE_SBP2
+	tristate "Storage devices (SBP-2 protocol)"
+	depends on FIREWIRE && SCSI
+	help
+	  This option enables you to use SBP-2 devices connected to a
+	  FireWire bus.  SBP-2 devices include storage devices like
+	  harddisks and DVD drives, also some other FireWire devices
+	  like scanners.
+
+	  To compile this driver as a module, say M here:  The module will be
+	  called firewire-sbp2.
+
+	  You should also enable support for disks, CD-ROMs, etc. in the SCSI
+	  configuration section.
+
+config FIREWIRE_NET
+	tristate "IP networking over 1394"
+	depends on FIREWIRE && INET
+	help
+	  This enables IPv4/IPv6 over IEEE 1394, providing IP connectivity
+	  with other implementations of RFC 2734/3146 as found on several
+	  operating systems.  Multicast support is currently limited.
+
+	  To compile this driver as a module, say M here:  The module will be
+	  called firewire-net.
+
+config FIREWIRE_NOSY
+	tristate "Nosy - a FireWire traffic sniffer for PCILynx cards"
+	depends on PCI
+	help
+	  Nosy is an IEEE 1394 packet sniffer that is used for protocol
+	  analysis and in development of IEEE 1394 drivers, applications,
+	  or firmwares.
+
+	  This driver lets you use a Texas Instruments PCILynx 1394 to PCI
+	  link layer controller TSB12LV21/A/B as a low-budget bus analyzer.
+	  PCILynx is a nowadays very rare IEEE 1394 controller which is
+	  not OHCI 1394 compliant.
+
+	  The following cards are known to be based on PCILynx or PCILynx-2:
+	  IOI IOI-1394TT (PCI card), Unibrain Fireboard 400 PCI Lynx-2
+	  (PCI card), Newer Technology FireWire 2 Go (CardBus card),
+	  Apple Power Mac G3 blue & white and G4 with PCI graphics
+	  (onboard controller).
+
+	  To compile this driver as a module, say M here:  The module will be
+	  called nosy.  Source code of a userspace interface to nosy, called
+	  nosy-dump, can be found in tools/firewire/ of the kernel sources.
+
+	  If unsure, say N.
+
+endmenu