CVSROOT: /cvs
Module name: src
Changes by: d...@cvs.openbsd.org 2021/09/05 07:13:31
Modified files:
sys/arch/amd64/amd64: vmm.c
Log message:
vmm(4): fix vcpu locking issues reported by syzbot
Syzbot found 3 issues related to the new vcpu lock. This diff adds
a write lock to vm_rwregs (needed on VMX as vmread instructions
require taking ownership of the vcpu to load the VMCS) and prevents
locking the vcpu in vm_run if we fail the cas operation for toggling
vcpu state.
In the future, we can push the locking in vm_rwregs on AMD SVM
systems.
The panics in question:
panic: rw_enter: vcpulock locking against myself
panic: lock (rwlock) vcpulock not locked
panic: vcpulock: lock not held
Reported-by: syzbot+1dab11e14aa7a159c...@syzkaller.appspotmail.com
Reported-by: syzbot+36244e105daffa1a8...@syzkaller.appspotmail.com
Reported-by: syzbot+c78b5644c7dc3d9b6...@syzkaller.appspotmail.com
ok mlarkin@
