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, 286 insertions, 0 deletions

diff --git a/scripts/Makefile.package b/scripts/Makefile.package
new file mode 100644
index 000000000..6d36786ba
--- /dev/null
+++ b/scripts/Makefile.package
@@ -0,0 +1,286 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Makefile for the different targets used to generate full packages of a kernel
+
+include $(srctree)/scripts/Kbuild.include
+include $(srctree)/scripts/Makefile.lib
+
+# Git
+# ---------------------------------------------------------------------------
+
+filechk_HEAD = git -C $(srctree) rev-parse --verify HEAD 2>/dev/null
+
+.tmp_HEAD: check-git FORCE
+	$(call filechk,HEAD)
+
+PHONY += check-git
+check-git:
+	@if ! $(srctree)/scripts/check-git; then \
+		echo >&2 "error: creating source package requires git repository"; \
+		false; \
+	fi
+
+git-config-tar.gz   = -c tar.tar.gz.command="$(KGZIP)"
+git-config-tar.bz2  = -c tar.tar.bz2.command="$(KBZIP2)"
+git-config-tar.lzma = -c tar.tar.lzma.command="$(LZMA)"
+git-config-tar.xz   = -c tar.tar.xz.command="$(XZ)"
+git-config-tar.zst  = -c tar.tar.zst.command="$(ZSTD)"
+
+quiet_cmd_archive = ARCHIVE $@
+      cmd_archive = git -C $(srctree) $(git-config-tar$(suffix $@)) archive \
+                    --output=$$(realpath $@) $(archive-args)
+
+suffix-gzip  := .gz
+suffix-bzip2 := .bz2
+suffix-lzma  := .lzma
+suffix-xz    := .xz
+
+# Linux source tarball
+# ---------------------------------------------------------------------------
+
+linux-tarballs := $(addprefix linux, .tar.gz .tar.bz2 .tar.lzma .tar.xz)
+
+targets += $(linux-tarballs)
+$(linux-tarballs): archive-args = --prefix=linux/ $$(cat $<)
+$(linux-tarballs): .tmp_HEAD FORCE
+	$(call if_changed,archive)
+
+# rpm-pkg srcrpm-pkg binrpm-pkg
+# ---------------------------------------------------------------------------
+
+quiet_cmd_mkspec = GEN     $@
+      cmd_mkspec = $(srctree)/scripts/package/mkspec $@
+
+rpmbuild/SPECS/kernel.spec: FORCE
+	$(call cmd,mkspec)
+
+PHONY += rpm-sources
+rpm-sources: linux.tar.gz
+	$(Q)mkdir -p rpmbuild/SOURCES
+	$(Q)ln -f linux.tar.gz rpmbuild/SOURCES/linux.tar.gz
+	$(Q)cp $(KCONFIG_CONFIG) rpmbuild/SOURCES/config
+	$(Q)$(srctree)/scripts/package/gen-diff-patch rpmbuild/SOURCES/diff.patch
+
+PHONY += rpm-pkg srcrpm-pkg binrpm-pkg
+
+ifneq ($(CC),$(HOSTCC))
+rpm-no-devel = --without=devel
+endif
+
+rpm-pkg:    private build-type := a
+srcrpm-pkg: private build-type := s
+binrpm-pkg: private build-type := b
+
+rpm-pkg srcrpm-pkg: rpm-sources
+rpm-pkg srcrpm-pkg binrpm-pkg: rpmbuild/SPECS/kernel.spec
+	+$(strip rpmbuild -b$(build-type) rpmbuild/SPECS/kernel.spec \
+	--define='_topdir $(abspath rpmbuild)' \
+	$(if $(filter a b, $(build-type)), \
+		--target $(UTS_MACHINE)-linux --build-in-place --noprep --define='_smp_mflags %{nil}' \
+		$$(rpm -q rpm >/dev/null 2>&1 || echo --nodeps) \
+		$(rpm-no-devel)) \
+	$(RPMOPTS))
+
+# deb-pkg srcdeb-pkg bindeb-pkg
+# ---------------------------------------------------------------------------
+
+KDEB_SOURCE_COMPRESS ?= gzip
+
+supported-deb-source-compress := gzip bzip2 lzma xz
+
+PHONY += linux.tar.unsupported-deb-src-compress
+linux.tar.unsupported-deb-src-compress:
+	@echo "error: KDEB_SOURCE_COMPRESS=$(KDEB_SOURCE_COMPRESS) is not supported. The supported values are: $(supported-deb-source-compress)" >&2
+	@false
+
+debian-orig-suffix := \
+    $(strip $(if $(filter $(supported-deb-source-compress), $(KDEB_SOURCE_COMPRESS)), \
+    $(suffix-$(KDEB_SOURCE_COMPRESS)),.unsupported-deb-src-compress))
+
+quiet_cmd_debianize = GEN     $@
+      cmd_debianize = $(srctree)/scripts/package/mkdebian $(mkdebian-opts)
+
+debian: FORCE
+	$(call cmd,debianize)
+
+PHONY += debian-orig
+debian-orig: private source = $(shell dpkg-parsechangelog -S Source)
+debian-orig: private version = $(shell dpkg-parsechangelog -S Version | sed 's/-[^-]*$$//')
+debian-orig: private orig-name = $(source)_$(version).orig.tar$(debian-orig-suffix)
+debian-orig: mkdebian-opts = --need-source
+debian-orig: linux.tar$(debian-orig-suffix) debian
+	$(Q)if [ "$$(df  --output=target .. 2>/dev/null)" = "$$(df --output=target $< 2>/dev/null)" ]; then \
+		ln -f $< ../$(orig-name); \
+	else \
+		cp $< ../$(orig-name); \
+	fi
+
+PHONY += deb-pkg srcdeb-pkg bindeb-pkg
+
+deb-pkg:    private build-type := source,binary
+srcdeb-pkg: private build-type := source
+bindeb-pkg: private build-type := binary
+
+deb-pkg srcdeb-pkg: debian-orig
+bindeb-pkg: debian
+deb-pkg srcdeb-pkg bindeb-pkg:
+	+$(strip dpkg-buildpackage \
+	--build=$(build-type) --no-pre-clean --unsigned-changes \
+	$(if $(findstring source, $(build-type)), \
+		--unsigned-source --compression=$(KDEB_SOURCE_COMPRESS)) \
+	$(if $(findstring binary, $(build-type)), \
+		-R'$(MAKE) -f debian/rules' -j1 -a$$(cat debian/arch), \
+		--no-check-builddeps) \
+	$(DPKG_FLAGS))
+
+# snap-pkg
+# ---------------------------------------------------------------------------
+PHONY += snap-pkg
+snap-pkg:
+	rm -rf $(objtree)/snap
+	mkdir $(objtree)/snap
+	$(MAKE) clean
+	sed "s@KERNELRELEASE@$(KERNELRELEASE)@; \
+		s@SRCTREE@$(realpath $(srctree))@" \
+		$(srctree)/scripts/package/snapcraft.template > \
+		$(objtree)/snap/snapcraft.yaml
+	cd $(objtree)/snap && \
+	snapcraft --target-arch=$(UTS_MACHINE)
+
+# pacman-pkg
+# ---------------------------------------------------------------------------
+
+PHONY += pacman-pkg
+pacman-pkg:
+	@ln -srf $(srctree)/scripts/package/PKGBUILD $(objtree)/PKGBUILD
+	+BUILDDIR="$(realpath $(objtree))/pacman" \
+		CARCH="$(UTS_MACHINE)" \
+		KBUILD_MAKEFLAGS="$(MAKEFLAGS)" \
+		KBUILD_REVISION="$(shell $(srctree)/scripts/build-version)" \
+		makepkg $(MAKEPKGOPTS)
+
+# dir-pkg tar*-pkg - tarball targets
+# ---------------------------------------------------------------------------
+
+tar-install: FORCE
+	$(Q)$(MAKE) -f $(srctree)/Makefile
+	+$(Q)$(srctree)/scripts/package/buildtar $@
+
+compress-tar.gz  = -I "$(KGZIP)"
+compress-tar.bz2 = -I "$(KBZIP2)"
+compress-tar.xz  = -I "$(XZ)"
+compress-tar.zst = -I "$(ZSTD)"
+
+quiet_cmd_tar = TAR     $@
+      cmd_tar = cd $<; tar cf ../$@ $(compress-tar$(suffix $@)) --owner=root --group=root --sort=name *
+
+dir-tarballs := $(addprefix linux-$(KERNELRELEASE)-$(ARCH), .tar .tar.gz .tar.bz2 .tar.xz .tar.zst)
+
+$(dir-tarballs): tar-install
+	$(call cmd,tar)
+
+PHONY += dir-pkg
+dir-pkg: tar-install
+	@echo "Kernel tree successfully created in $<"
+
+PHONY += tar-pkg
+tar-pkg: linux-$(KERNELRELEASE)-$(ARCH).tar
+	@:
+
+tar%-pkg: linux-$(KERNELRELEASE)-$(ARCH).tar.% FORCE
+	@:
+
+# modules-cpio-pkg - generate an initramfs with the modules
+# ---------------------------------------------------------------------------
+
+.tmp_modules_cpio: FORCE
+	$(Q)$(MAKE) -f $(srctree)/Makefile
+	$(Q)rm -rf $@
+	$(Q)$(MAKE) -f $(srctree)/Makefile INSTALL_MOD_PATH=$@/$(INSTALL_MOD_PATH) modules_install
+
+quiet_cmd_cpio = CPIO    $@
+      cmd_cpio = $(CONFIG_SHELL) $(srctree)/usr/gen_initramfs.sh -o $@ $<
+
+modules-$(KERNELRELEASE)-$(ARCH).cpio: .tmp_modules_cpio
+	$(call cmd,cpio)
+
+PHONY += modules-cpio-pkg
+modules-cpio-pkg: modules-$(KERNELRELEASE)-$(ARCH).cpio
+	@:
+
+# perf-tar*-src-pkg - generate a source tarball with perf source
+# ---------------------------------------------------------------------------
+
+.tmp_perf:
+	$(Q)mkdir .tmp_perf
+
+.tmp_perf/HEAD: .tmp_HEAD | .tmp_perf
+	$(call cmd,copy)
+
+quiet_cmd_perf_version_file = GEN     $@
+      cmd_perf_version_file = cd $(srctree)/tools/perf; util/PERF-VERSION-GEN $(dir $(abspath $@))
+
+# PERF-VERSION-FILE and .tmp_HEAD are independent, but this avoids updating the
+# timestamp of PERF-VERSION-FILE.
+# The best is to fix tools/perf/util/PERF-VERSION-GEN.
+.tmp_perf/PERF-VERSION-FILE: .tmp_HEAD $(srctree)/tools/perf/util/PERF-VERSION-GEN | .tmp_perf
+	$(call cmd,perf_version_file)
+
+perf-archive-args = --add-file=$$(realpath $(word 2, $^)) \
+	--add-file=$$(realpath $(word 3, $^)) \
+	$$(cat $(word 2, $^))^{tree} $$(cat $<)
+
+
+perf-tarballs := $(addprefix perf-$(KERNELVERSION), .tar .tar.gz .tar.bz2 .tar.xz .tar.zst)
+
+targets += $(perf-tarballs)
+$(perf-tarballs): archive-args = --prefix=perf-$(KERNELVERSION)/ $(perf-archive-args)
+$(perf-tarballs): tools/perf/MANIFEST .tmp_perf/HEAD .tmp_perf/PERF-VERSION-FILE FORCE
+	$(call if_changed,archive)
+
+PHONY += perf-tar-src-pkg
+perf-tar-src-pkg: perf-$(KERNELVERSION).tar
+	@:
+
+perf-tar%-src-pkg: perf-$(KERNELVERSION).tar.% FORCE
+	@:
+
+# Help text displayed when executing 'make help'
+# ---------------------------------------------------------------------------
+PHONY += help
+help:
+	@echo '  rpm-pkg             - Build both source and binary RPM kernel packages'
+	@echo '  srcrpm-pkg          - Build only the source kernel RPM package'
+	@echo '  binrpm-pkg          - Build only the binary kernel RPM package'
+	@echo '  deb-pkg             - Build both source and binary deb kernel packages'
+	@echo '  srcdeb-pkg          - Build only the source kernel deb package'
+	@echo '  bindeb-pkg          - Build only the binary kernel deb package'
+	@echo '  snap-pkg            - Build only the binary kernel snap package'
+	@echo '                        (will connect to external hosts)'
+	@echo '  pacman-pkg          - Build only the binary kernel pacman package'
+	@echo '  dir-pkg             - Build the kernel as a plain directory structure'
+	@echo '  tar-pkg             - Build the kernel as an uncompressed tarball'
+	@echo '  targz-pkg           - Build the kernel as a gzip compressed tarball'
+	@echo '  tarbz2-pkg          - Build the kernel as a bzip2 compressed tarball'
+	@echo '  tarxz-pkg           - Build the kernel as a xz compressed tarball'
+	@echo '  tarzst-pkg          - Build the kernel as a zstd compressed tarball'
+	@echo '  modules-cpio-pkg    - Build the kernel modules as cpio archive'
+	@echo '                        (uses INSTALL_MOD_PATH inside the archive)'
+	@echo '  perf-tar-src-pkg    - Build the perf source tarball with no compression'
+	@echo '  perf-targz-src-pkg  - Build the perf source tarball with gzip compression'
+	@echo '  perf-tarbz2-src-pkg - Build the perf source tarball with bz2 compression'
+	@echo '  perf-tarxz-src-pkg  - Build the perf source tarball with xz compression'
+	@echo '  perf-tarzst-src-pkg - Build the perf source tarball with zst compression'
+
+PHONY += FORCE
+FORCE:
+
+# Read all saved command lines and dependencies for the $(targets) we
+# may be building above, using $(if_changed{,_dep}). As an
+# optimization, we don't need to read them if the target does not
+# exist, we will rebuild anyway in that case.
+
+existing-targets := $(wildcard $(sort $(targets)))
+
+-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
+
+.PHONY: $(PHONY)