From 4b1eded1f91812d576538f106b57352d25a6b484 Mon Sep 17 00:00:00 2001 From: Alexander Potapenko Date: Tue, 24 Sep 2024 15:23:14 +0200 Subject: executor: arm64: sys/linux: implement syz_kvm_setup_syzos_vm and syz_kvm_add_vcpu The old syz_kvm_setup_cpu() API mixed together VM and VCPU setup, making it harder to create and fuzz two VCPUs in the same VM. Introduce two new pseudo-syscalls, syz_kvm_setup_syzos_vm() and syz_kvm_add_vcpu(), that will simplify this task. syz_kvm_setup_syzos_vm() takes a VM file descriptor, performs VM setup (allocates guest memory and installs SYZOS code into it) and returns a new kvm_syz_vm resource, which is in fact a pointer to `struct kvm_syz_vm` encapsulating VM-specific data in the C code. syz_kvm_add_vcpu() takes the VM ID denoted by kvm_syz_vm and creates a new VCPU within that VM with a proper CPU number. It then stores the fuzzer-supplied SYZOS API sequence into the corresponding part (indexed by CPU number) of the VM memory slot, and sets up the CPU registers to interpret that sequence. The new pseudo-syscall let the fuzzer create independent CPUs that run different code sequences without interfering with each other. --- pkg/subsystem/linux/rules.go | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'pkg/subsystem/linux/rules.go') diff --git a/pkg/subsystem/linux/rules.go b/pkg/subsystem/linux/rules.go index f152c2695..78adee1e9 100644 --- a/pkg/subsystem/linux/rules.go +++ b/pkg/subsystem/linux/rules.go @@ -49,7 +49,7 @@ var ( "isofs": {"syz_mount_image$iso9660"}, "jffs2": {"syz_mount_image$jffs2"}, "jfs": {"syz_mount_image$jfs"}, - "kvm": {"syz_kvm_setup_cpu", "syz_kvm_vgic_v3_setup"}, + "kvm": {"syz_kvm_setup_cpu", "syz_kvm_vgic_v3_setup", "syz_kvm_setup_syzos_vm", "syz_kvm_add_vcpu"}, "minix": {"syz_mount_image$minix"}, "nilfs": {"syz_mount_image$nilfs2"}, "ntfs3": {"syz_mount_image$ntfs", "syz_mount_image$ntfs3"}, -- cgit mrf-deployment