panic: munmap(7f9e5fe00000, 200000)) failed: function not implemented

goroutine 389 [running]:
DIAGNOSIS:


Error collecting stacks: failed to run ["/syzkaller/managers/ptrace-proxy-sandbox-race/current/image" "-root" "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "-watchdog-action=panic" "-network=none" "-debug" "-platform=ptrace" "-file-access=shared" "-network=sandbox" "debug" "-stacks" "ci-gvisor-ptrace-proxy-sandbox-race-2"]: exit status 128
I0317 03:04:42.269260   46511 x:0] ***************************
I0317 03:04:42.269684   46511 x:0] Args: [/syzkaller/managers/ptrace-proxy-sandbox-race/current/image -root /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root -watchdog-action=panic -network=none -debug -platform=ptrace -file-access=shared -network=sandbox debug -stacks ci-gvisor-ptrace-proxy-sandbox-race-2]
I0317 03:04:42.269779   46511 x:0] Git Revision: 5496be7c5ddedd6ec03004143501acb225eda357
I0317 03:04:42.269801   46511 x:0] PID: 46511
I0317 03:04:42.269832   46511 x:0] UID: 0, GID: 0
I0317 03:04:42.269866   46511 x:0] Configuration:
I0317 03:04:42.269882   46511 x:0] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0317 03:04:42.269899   46511 x:0] 		Platform: ptrace
I0317 03:04:42.270213   46511 x:0] 		FileAccess: shared, overlay: false
I0317 03:04:42.270264   46511 x:0] 		Network: sandbox, logging: false
I0317 03:04:42.270288   46511 x:0] 		Strace: false, max size: 1024, syscalls: []
I0317 03:04:42.270313   46511 x:0] ***************************
D0317 03:04:42.271159   46511 x:0] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0317 03:04:42.292212   46511 x:0] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-2": signal 0
D0317 03:04:42.292315   46511 x:0] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0317 03:04:42.292363   46511 x:0] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0317 03:04:42.294346   46511 x:0] urpc: successfully marshalled 117 bytes.
I0317 03:04:42.729969   46511 x:0] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2", PID: 18475
I0317 03:04:42.730052   46511 x:0] Retrieving sandbox stacks
D0317 03:04:42.730360   46511 x:0] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0317 03:04:42.730389   46511 x:0] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0317 03:04:42.730518   46511 x:0] urpc: successfully marshalled 36 bytes.
W0317 03:04:42.828274   46511 x:0] FATAL ERROR: retrieving stacks: getting sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2" stacks: urpc method "debug.Stacks" failed: connection reset by peer
retrieving stacks: getting sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2" stacks: urpc method "debug.Stacks" failed: connection reset by peer
gvisor.googlesource.com/gvisor/pkg/sentry/platform/ptrace.(*subprocess).Unmap(0xc0001a4300, 0x7f9e5fe00000, 0x200000)
	pkg/sentry/platform/ptrace/subprocess.go:608 +0x43f
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).unmapASLocked(0xc000934d80, 0x7f9e5fe00000, 0x7f9e60000000)
	pkg/sentry/mm/address_space.go:215 +0xf8
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).breakCopyOnWriteLocked(0xc000934d80, 0xc000935480, 0x6, 0x7f9e5fe5a000, 0x7f9e5fe5b000, 0x7f9e5fe5a000, 0x7f9e5fe5b000, 0xc000935480, 0x6, 0xc000935480)
	pkg/sentry/mm/pma.go:457 +0xd0f
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).getPMAsLocked(0xc000934d80, 0x1286180, 0xc0007d5500, 0xc000934e00, 0xa, 0x7f9e5fe5a000, 0x7f9e5fe5b000, 0x1, 0xc000934e00, 0xb, ...)
	pkg/sentry/mm/pma.go:146 +0x399
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).HandleUserFault(0xc000934d80, 0x1286180, 0xc0007d5500, 0x7f9e5fe5aab8, 0x101, 0x7f9e5fe5aac0, 0xc001068c00, 0x100)
	pkg/sentry/mm/syscalls.go:57 +0x1b1
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*runApp).execute(0x0, 0xc0007d5500, 0x126dae0, 0x0)
	pkg/sentry/kernel/task_run.go:251 +0xc91
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).run(0xc0007d5500, 0x64)
	pkg/sentry/kernel/task_run.go:91 +0x2e6
created by gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:279 +0x19e