panic: munmap(7f0e9ee00000, 200000)) failed: function not implemented

DIAGNOSIS:
I1025 17:22:02.883888   43004 x:0] ***************************
I1025 17:22:02.884056   43004 x:0] Args: [/syzkaller/managers/ptrace-direct-overlay-host-race/current/image -root /syzkaller/managers/ptrace-direct-overlay-host-race/workdir/gvisor_root -watchdog-action=panic -network=none -debug -alsologtostderr -platform=ptrace -file-access=exclusive -overlay -network=host -TESTONLY-unsafe-nonroot debug -stacks ci-gvisor-ptrace-direct-overlay-host-race-1]
I1025 17:22:02.884192   43004 x:0] Version release-20190806.1-322-g27e896f2905e
I1025 17:22:02.884241   43004 x:0] PID: 43004
I1025 17:22:02.884286   43004 x:0] UID: 0, GID: 0
I1025 17:22:02.884317   43004 x:0] Configuration:
I1025 17:22:02.884371   43004 x:0] 		RootDir: /syzkaller/managers/ptrace-direct-overlay-host-race/workdir/gvisor_root
I1025 17:22:02.884401   43004 x:0] 		Platform: ptrace
I1025 17:22:02.884449   43004 x:0] 		FileAccess: exclusive, overlay: true
I1025 17:22:02.884512   43004 x:0] 		Network: host, logging: false
I1025 17:22:02.884561   43004 x:0] 		Strace: false, max size: 1024, syscalls: []
I1025 17:22:02.884621   43004 x:0] ***************************
W1025 17:22:02.884658   43004 x:0] Block the TERM signal. This is only safe in tests!
D1025 17:22:02.884800   43004 x:0] Load container "/syzkaller/managers/ptrace-direct-overlay-host-race/workdir/gvisor_root" "ci-gvisor-ptrace-direct-overlay-host-race-1"
D1025 17:22:02.920026   43004 x:0] Signal container "ci-gvisor-ptrace-direct-overlay-host-race-1": signal 0
D1025 17:22:02.920187   43004 x:0] Signal sandbox "ci-gvisor-ptrace-direct-overlay-host-race-1"
D1025 17:22:02.920253   43004 x:0] Connecting to sandbox "ci-gvisor-ptrace-direct-overlay-host-race-1"
D1025 17:22:02.991200   43004 x:0] urpc: successfully marshalled 123 bytes.
I1025 17:22:03.368512   43004 x:0] Found sandbox "ci-gvisor-ptrace-direct-overlay-host-race-1", PID: 48916
I1025 17:22:03.368633   43004 x:0] Retrieving sandbox stacks
D1025 17:22:03.368672   43004 x:0] Stacks sandbox "ci-gvisor-ptrace-direct-overlay-host-race-1"
D1025 17:22:03.368749   43004 x:0] Connecting to sandbox "ci-gvisor-ptrace-direct-overlay-host-race-1"
D1025 17:22:03.368944   43004 x:0] urpc: successfully marshalled 36 bytes.
W1025 17:22:03.465829   43004 x:0] FATAL ERROR: retrieving stacks: getting sandbox "ci-gvisor-ptrace-direct-overlay-host-race-1" stacks: urpc method "debug.Stacks" failed: connection reset by peer
retrieving stacks: getting sandbox "ci-gvisor-ptrace-direct-overlay-host-race-1" stacks: urpc method "debug.Stacks" failed: connection reset by peer
W1025 17:22:03.466113   43004 x:0] Failure to execute command, err: 1