syzbot

fatal error: concurrent map read and map write

goroutine 107331 [running]:
runtime.throw(0xba9858, 0x21)
	GOROOT/src/runtime/panic.go:616 +0x81 fp=0xc421217d20 sp=0xc421217d00 pc=0x429441
runtime.mapaccess2_fast64(0xa9ede0, 0xc421660480, 0xc421fd4030, 0x10a0980, 0x411400)
	GOROOT/src/runtime/hashmap_fast.go:141 +0x1aa fp=0xc421217d48 sp=0xc421217d20 pc=0x409e9a
gvisor.googlesource.com/gvisor/pkg/sentry/platform/ring0/pagetables.(*PCIDs).Drop(...)
	pkg/sentry/platform/ring0/pagetables/pcids_x86.go:91
gvisor.googlesource.com/gvisor/pkg/sentry/platform/kvm.(*machine).dropPageTables(0xc420166400, 0xc421fd4030)
	pkg/sentry/platform/kvm/machine_amd64.go:89 +0x11c fp=0xc421217e18 sp=0xc421217d48 pc=0x87574c
gvisor.googlesource.com/gvisor/pkg/sentry/platform/kvm.(*addressSpace).Release(0xc420437200)
	pkg/sentry/platform/kvm/address_space.go:287 +0x81 fp=0xc421217e40 sp=0xc421217e18 pc=0x86a481
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).DecUsers(0xc421fc8000, 0xc53b00, 0xc42093f240)
	pkg/sentry/mm/lifecycle.go:210 +0x204 fp=0xc421217ed0 sp=0xc421217e40 pc=0x684cf4
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*TaskContext).release(0xc421348730)
	pkg/sentry/kernel/task_context.go:64 +0xd6 fp=0xc421217f30 sp=0xc421217ed0 pc=0x6ddbe6
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*runExitMain).execute(0x0, 0xc421348000, 0xc46660, 0x0)
	pkg/sentry/kernel/task_exit.go:266 +0xc5 fp=0xc421217f88 sp=0xc421217f30 pc=0x6dfae5
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).run(0xc421348000, 0x476)
	pkg/sentry/kernel/task_run.go:95 +0x174 fp=0xc421217fd0 sp=0xc421217f88 pc=0x6e6f04
runtime.goexit()
	bazel-out/k8-fastbuild/bin/external/io_bazel_rules_go/linux_amd64_pure_stripped/stdlib~/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc421217fd8 sp=0xc421217fd0 pc=0x455f31
created by gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:258 +0x100