panic: Incrementing non-positive ref count
DIAGNOSIS:
I0201 17:07:18.930078   26308 log.go:209] ***************************
I0201 17:07:18.930209   26308 log.go:209] 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 --ps ci-gvisor-ptrace-direct-overlay-host-race-0]
I0201 17:07:18.930432   26308 log.go:209] Version release-20200127.0-51-g02997af5abd6
I0201 17:07:18.930509   26308 log.go:209] PID: 26308
I0201 17:07:18.930582   26308 log.go:209] UID: 0, GID: 0
I0201 17:07:18.930664   26308 log.go:209] Configuration:
I0201 17:07:18.930738   26308 log.go:209] 		RootDir: /syzkaller/managers/ptrace-direct-overlay-host-race/workdir/gvisor_root
I0201 17:07:18.930820   26308 log.go:209] 		Platform: ptrace
I0201 17:07:18.930880   26308 log.go:209] 		FileAccess: exclusive, overlay: true
I0201 17:07:18.930964   26308 log.go:209] 		Network: host, logging: false
I0201 17:07:18.931038   26308 log.go:209] 		Strace: false, max size: 1024, syscalls: []
I0201 17:07:18.931095   26308 log.go:209] ***************************
W0201 17:07:18.931161   26308 log.go:216] Block the TERM signal. This is only safe in tests!
D0201 17:07:18.931328   26308 log.go:202] Load container "/syzkaller/managers/ptrace-direct-overlay-host-race/workdir/gvisor_root" "ci-gvisor-ptrace-direct-overlay-host-race-0"
D0201 17:07:18.937790   26308 log.go:202] Signal container "ci-gvisor-ptrace-direct-overlay-host-race-0": signal 0
D0201 17:07:18.952149   26308 log.go:202] Signal sandbox "ci-gvisor-ptrace-direct-overlay-host-race-0"
D0201 17:07:18.952419   26308 log.go:202] Connecting to sandbox "ci-gvisor-ptrace-direct-overlay-host-race-0"
D0201 17:07:18.953083   26308 log.go:202] urpc: successfully marshalled 123 bytes.
I0201 17:07:19.098926   26308 log.go:209] Found sandbox "ci-gvisor-ptrace-direct-overlay-host-race-0", PID: 6709
I0201 17:07:19.099039   26308 log.go:209] Retrieving sandbox stacks
D0201 17:07:19.099117   26308 log.go:202] Stacks sandbox "ci-gvisor-ptrace-direct-overlay-host-race-0"
D0201 17:07:19.099234   26308 log.go:202] Connecting to sandbox "ci-gvisor-ptrace-direct-overlay-host-race-0"
W0201 17:07:19.099401   26308 log.go:216] FATAL ERROR: retrieving stacks: connecting to control server at PID 6709: connection refused
retrieving stacks: connecting to control server at PID 6709: connection refused
W0201 17:07:19.099669   26308 log.go:216] Failure to execute command, err: 1