From cfac82c560e514333ebb1de772778554d1aca49c Mon Sep 17 00:00:00 2001 From: Ovidiu Panait Date: Fri, 21 Oct 2022 13:25:36 +0300 Subject: syzkaller: add recipe and selftest for syzkaller fuzzing Syzkaller is a coverage-guided fuzzer that is widely used to find bugs in the Linux kernel: https://github.com/google/syzkaller Add the recipe and a selftest for running the fuzzer in a qemux86-64 kvm environment. The following steps can be used to start the test: """ cat >> conf/local.conf </crashes directory will contain the report files for all the bugs found. Signed-off-by: Ovidiu Panait Signed-off-by: Khem Raj --- meta-oe/lib/oeqa/selftest/cases/syzkaller.py | 124 +++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 meta-oe/lib/oeqa/selftest/cases/syzkaller.py (limited to 'meta-oe/lib/oeqa/selftest/cases') diff --git a/meta-oe/lib/oeqa/selftest/cases/syzkaller.py b/meta-oe/lib/oeqa/selftest/cases/syzkaller.py new file mode 100644 index 0000000000..64fc864bf8 --- /dev/null +++ b/meta-oe/lib/oeqa/selftest/cases/syzkaller.py @@ -0,0 +1,124 @@ +# +# SPDX-License-Identifier: MIT +# + +from oeqa.selftest.case import OESelftestTestCase +from oeqa.utils.commands import runCmd, bitbake, get_bb_var, get_bb_vars +from oeqa.utils.network import get_free_port + +class TestSyzkaller(OESelftestTestCase): + def setUpSyzkallerConfig(self, os_arch, qemu_postfix): + syz_target_sysroot = get_bb_var('PKGD', 'syzkaller') + syz_target = os.path.join(syz_target_sysroot, 'usr') + + qemu_native_bin = os.path.join(self.syz_native_sysroot, 'usr/bin/qemu-system-' + qemu_postfix) + kernel_cmdline = "ip=dhcp rootfs=/dev/sda dummy_hcd.num=%s" % (self.dummy_hcd_num) + kernel_objdir = self.deploy_dir_image + port = get_free_port() + + if not os.path.exists(self.syz_workdir): + os.mkdir(self.syz_workdir) + + with open(self.syz_cfg, 'w') as f: + f.write( +""" +{ + "target": "%s", + "http": "127.0.0.1:%s", + "workdir": "%s", + "kernel_obj": "%s", + "kernel_src": "%s", + "image": "%s", + "syzkaller": "%s", + "type": "qemu", + "reproduce" : false, + "sandbox": "none", + "vm": { + "count": %s, + "kernel": "%s", + "cmdline": "%s", + "cpu": %s, + "mem": %s, + "qemu": "%s", + "qemu_args": "-device virtio-scsi-pci,id=scsi -device scsi-hd,drive=rootfs -enable-kvm -cpu host,migratable=off", + "image_device": "drive index=0,id=rootfs,if=none,media=disk,file=" + } +} +""" +% (os_arch, port, self.syz_workdir, kernel_objdir, self.kernel_src, + self.rootfs, syz_target, self.syz_qemu_vms, self.kernel, kernel_cmdline, + self.syz_qemu_cpus, self.syz_qemu_mem, qemu_native_bin)) + + def test_syzkallerFuzzingQemux86_64(self): + self.image = 'core-image-minimal' + self.machine = 'qemux86-64' + self.fstype = "ext4" + + self.write_config( +""" +MACHINE = "%s" +IMAGE_FSTYPES = "%s" +KERNEL_IMAGETYPES += "vmlinux" +EXTRA_IMAGE_FEATURES += " ssh-server-openssh" +IMAGE_ROOTFS_EXTRA_SPACE = "512000" +KERNEL_EXTRA_FEATURES += " \ + cfg/debug/syzkaller/debug-syzkaller.scc \ +" +IMAGE_INSTALL:append = " syzkaller" +""" +% (self.machine, self.fstype)) + + build_vars = ['TOPDIR', 'DEPLOY_DIR_IMAGE', 'STAGING_KERNEL_DIR'] + syz_fuzz_vars = ['SYZ_WORKDIR', 'SYZ_FUZZTIME', 'SYZ_QEMU_MEM', 'SYZ_QEMU_CPUS', 'SYZ_QEMU_VM_COUNT'] + syz_aux_vars = ['SYZ_DUMMY_HCD_NUM'] + + needed_vars = build_vars + syz_fuzz_vars + syz_aux_vars + bb_vars = get_bb_vars(needed_vars) + + for var in syz_fuzz_vars: + if not bb_vars[var]: + self.skipTest( +""" +%s variable not set. +Please configure %s fuzzing parameters to run this test. + +Example local.conf config: +SYZ_WORKDIR="" # syzkaller workdir location (must be persistent across os-selftest runs) +SYZ_FUZZTIME="30" # fuzzing time in minutes +SYZ_QEMU_VM_COUNT="1" # number of qemu VMs to be used for fuzzing +SYZ_QEMU_MEM="2048"' # memory used by each qemu VM +SYZ_QEMU_CPUS="2"' # number of cpus used by each qemu VM +""" +% (var, ', '.join(syz_fuzz_vars))) + + self.topdir = bb_vars['TOPDIR'] + self.deploy_dir_image = bb_vars['DEPLOY_DIR_IMAGE'] + self.kernel_src = bb_vars['STAGING_KERNEL_DIR'] + + """ + SYZ_WORKDIR must be set to an absolute path where syzkaller will store + the corpus database, config, runtime and crash data generated during + fuzzing. It must be persistent between oe-selftest runs, so the fuzzer + does not start over again on each run. + """ + self.syz_workdir = bb_vars['SYZ_WORKDIR'] + self.syz_fuzztime = int(bb_vars['SYZ_FUZZTIME']) * 60 + self.syz_qemu_mem = int(bb_vars['SYZ_QEMU_MEM']) + self.syz_qemu_cpus = int(bb_vars['SYZ_QEMU_CPUS']) + self.syz_qemu_vms = int(bb_vars['SYZ_QEMU_VM_COUNT']) + self.dummy_hcd_num = int(bb_vars['SYZ_DUMMY_HCD_NUM'] or 8) + + self.syz_cfg = os.path.join(self.syz_workdir, 'syzkaller.cfg') + self.kernel = os.path.join(self.deploy_dir_image, 'bzImage') + self.rootfs = os.path.join(self.deploy_dir_image, '%s-%s.%s' % (self.image, self.machine, self.fstype)) + + self.syz_native_sysroot = get_bb_var('RECIPE_SYSROOT_NATIVE', 'syzkaller-native') + + self.setUpSyzkallerConfig("linux/amd64", "x86_64") + + bitbake(self.image) + bitbake('syzkaller') + bitbake('syzkaller-native -c addto_recipe_sysroot') + + cmd = "syz-manager -config %s" % self.syz_cfg + runCmd(cmd, native_sysroot = self.syz_native_sysroot, timeout=self.syz_fuzztime, output_log=self.logger, ignore_status=True, shell=True) -- cgit 1.2.3-korg