afl

• Create root file system image

cd $IMAGE/
wget https://raw.githubusercontent.com/google/syzkaller/master/tools/create-image.sh -O create-image.sh
chmod +x create-image.sh
./create-image.sh

-d buster for Debian 10, and -s 16384 for larger disk size.

git clone kernel

make CC="$GCC/bin/gcc" defconfig

CONFIG_KCOV=y

CONFIG_DEBUG_INFO = y

Coverage collection.

CONFIG_KCOV=y

Debug info for symbolization.

CONFIG_DEBUG_INFO=y

Memory bug detector

CONFIG_KASAN=y

CONFIG_KASAN_INLINE=y

Required for Debian Stretch

CONFIG_CONFIGFS_FS=y

CONFIG_SECURITYFS=y

For 9p

CONFIG_NET_9P=y
CONFIG_NET_9P_VIRTIO=y
CONFIG_NET_9P_DEBUG=y (Optional)
CONFIG_9P_FS=y
CONFIG_9P_FS_POSIX_ACL=y
CONFIG_PCI=y
CONFIG_VIRTIO_PCI=y

Whenever Needed

make CC="$GCC/bin/gcc" olddefconfig

cat /etc/udev/rules.d/10-rename-network.rules SUBSYSTEM=="net", ACTION=="add", ATTR{address}="52:54:00:12:34:56", NAME="eth0"

9P Instructions

https://wiki.qemu.org/Documentation/9psetup

Final AFL Command

afl-fuzz -i afl_in -o afl_out ./programtorun @@

Result

Error happened on file with 200 lines. Happened after running a-d, and then running a again. On 50 lines, ran a-d twice, no results