Hi Andrew,
On Mon, 30 May 2022 at 04:00, Andrew Scull ascull@google.com wrote:
This series introduces ASAN and a basic fuzzing infrastructure that works with sandbox. The example fuzz test towards the end of the series will find something pretty quickly. That something is fixed by the series "virtio: Harden and test vring" that needs to be applied for the final patch in this series.
There is some refactoring to stop using '.' prefixed sections. ELF defines sections with names that contain anything that isn't alphanumeric or an underscore as being for system use which means clang's ASAN instrumentation happily add redzones between the contained objects. That's not what we want for things like linker lists where the linker script has carefully placed the sections contiguously. By renaming the sections, clang sees them as user sections and doesn't add instrumentation.
ASAN is left disabled by default as there are still some tests that it triggers on and will need some more investigation to fix. It can be enabled with CONFIG_ASAN or passing `-a ASAN` to buildman.
I abandonded the previous attempts to refactor sandbox EFI and getopt declaration as the changes resulted in problems out of the scope of this CL. I haven't tried to understand what EFI on sandbox should look like, but I have found that the linker list implementation is very brittle when up against compiler optimisation since ef123c5253 started to use static, zero-length arrays to mark the beginning and end of lists but the compiler see this as something it can get rid of.
From v1:
- corrected handling of EFI symbols by sandbox linker script
- per comments, some renaming and explaining
- dropped RFC for dlmalloc ASAN instrumentation (work required to improve it)
- added patch to reduce logging noise in fuzzer
From v2:
- remove sandbox EFI and getopt refactoring, they obstruct the series
- resolve a couple more ASAN errors
- fix LTO, xtensa and MIPS builds
- add ASAN build targets for CI
Andrew Scull (13): serial: sandbox: Fix buffer underflow in puts sandbox: Rename EFI runtime sections sandbox: Rename getopt sections linker_lists: Rename sections to remove . prefix sandbox: Add support for Address Sanitizer test/py: test_stackprotector: Disable for ASAN CI: Azure: Build with ASAN enabled fuzzing_engine: Add fuzzing engine uclass test: fuzz: Add framework for fuzzing sandbox: Decouple program entry from sandbox init sandbox: Add libfuzzer integration sandbox: Implement fuzzing engine driver fuzz: virtio: Add fuzzer for vring
.azure-pipelines.yml | 6 ++ Kconfig | 16 ++++ arch/Kconfig | 2 + arch/arc/cpu/u-boot.lds | 4 +- arch/arm/config.mk | 4 +- arch/arm/cpu/arm926ejs/sunxi/u-boot-spl.lds | 4 +- arch/arm/cpu/armv7/sunxi/u-boot-spl.lds | 4 +- arch/arm/cpu/armv8/u-boot-spl.lds | 4 +- arch/arm/cpu/armv8/u-boot.lds | 4 +- arch/arm/cpu/u-boot-spl.lds | 4 +- arch/arm/cpu/u-boot.lds | 6 +- arch/arm/mach-at91/arm926ejs/u-boot-spl.lds | 2 +- arch/arm/mach-at91/armv7/u-boot-spl.lds | 2 +- arch/arm/mach-omap2/u-boot-spl.lds | 4 +- arch/arm/mach-orion5x/u-boot-spl.lds | 4 +- arch/arm/mach-rockchip/u-boot-tpl-v8.lds | 4 +- arch/arm/mach-zynq/u-boot-spl.lds | 4 +- arch/arm/mach-zynq/u-boot.lds | 4 +- arch/m68k/cpu/u-boot.lds | 4 +- arch/microblaze/cpu/u-boot-spl.lds | 4 +- arch/microblaze/cpu/u-boot.lds | 4 +- arch/mips/config.mk | 2 +- arch/mips/cpu/u-boot-spl.lds | 4 +- arch/mips/cpu/u-boot.lds | 4 +- arch/nios2/cpu/u-boot.lds | 4 +- arch/powerpc/cpu/mpc83xx/u-boot.lds | 4 +- arch/powerpc/cpu/mpc85xx/u-boot-spl.lds | 4 +- arch/powerpc/cpu/mpc85xx/u-boot.lds | 4 +- arch/riscv/cpu/u-boot-spl.lds | 4 +- arch/riscv/cpu/u-boot.lds | 4 +- arch/sandbox/config.mk | 21 ++++- arch/sandbox/cpu/os.c | 76 +++++++++++++++++ arch/sandbox/cpu/start.c | 2 +- arch/sandbox/cpu/u-boot-spl.lds | 10 +-- arch/sandbox/cpu/u-boot.lds | 32 ++++---- arch/sandbox/dts/test.dts | 4 + arch/sandbox/include/asm/fuzzing_engine.h | 25 ++++++ arch/sandbox/include/asm/getopt.h | 2 +- arch/sandbox/include/asm/main.h | 18 ++++ arch/sandbox/include/asm/sections.h | 4 +- arch/sandbox/lib/sections.c | 8 +- arch/sh/cpu/u-boot.lds | 4 +- arch/x86/cpu/u-boot-64.lds | 6 +- arch/x86/cpu/u-boot-spl.lds | 6 +- arch/x86/cpu/u-boot.lds | 6 +- arch/x86/lib/elf_ia32_efi.lds | 4 +- arch/x86/lib/elf_x86_64_efi.lds | 4 +- arch/xtensa/cpu/u-boot.lds | 4 +- arch/xtensa/include/asm/ldscript.h | 13 ++- board/compulab/cm_t335/u-boot.lds | 4 +- board/cssi/MCR3000/u-boot.lds | 4 +- .../davinci/da8xxevm/u-boot-spl-da850evm.lds | 2 +- board/qualcomm/dragonboard820c/u-boot.lds | 4 +- board/samsung/common/exynos-uboot-spl.lds | 4 +- board/synopsys/iot_devkit/u-boot.lds | 4 +- board/ti/am335x/u-boot.lds | 4 +- board/vscom/baltos/u-boot.lds | 4 +- doc/api/linker_lists.rst | 22 ++--- doc/develop/commands.rst | 4 +- doc/develop/driver-model/of-plat.rst | 4 +- drivers/Kconfig | 2 + drivers/Makefile | 1 + drivers/fuzz/Kconfig | 17 ++++ drivers/fuzz/Makefile | 8 ++ drivers/fuzz/fuzzing_engine-uclass.c | 28 +++++++ drivers/fuzz/sandbox_fuzzing_engine.c | 35 ++++++++ drivers/serial/sandbox.c | 2 +- include/dm/uclass-id.h | 1 + include/fuzzing_engine.h | 51 ++++++++++++ include/linker_lists.h | 18 ++-- include/test/fuzz.h | 51 ++++++++++++ test/Makefile | 1 + test/fuzz/Makefile | 8 ++ test/fuzz/cmd_fuzz.c | 82 +++++++++++++++++++ test/fuzz/virtio.c | 72 ++++++++++++++++ test/py/tests/test_stackprotector.py | 1 + tools/mips-relocs.c | 9 +- 77 files changed, 673 insertions(+), 151 deletions(-) create mode 100644 arch/sandbox/include/asm/fuzzing_engine.h create mode 100644 arch/sandbox/include/asm/main.h create mode 100644 drivers/fuzz/Kconfig create mode 100644 drivers/fuzz/Makefile create mode 100644 drivers/fuzz/fuzzing_engine-uclass.c create mode 100644 drivers/fuzz/sandbox_fuzzing_engine.c create mode 100644 include/fuzzing_engine.h create mode 100644 include/test/fuzz.h create mode 100644 test/fuzz/Makefile create mode 100644 test/fuzz/cmd_fuzz.c create mode 100644 test/fuzz/virtio.c
Could you please add some documentation about this in doc/ ? I also wonder if we can make the fuzz test run in CI? Finally, can the azure stuff work in gitlab too?
I am interested in using fuzzing to test a new 'Universal Payload' feature which basically converts data from a C struct to a devicetree and back.
Regards, Simon