panic: Incrementing non-positive ref count

DIAGNOSIS:
I1218 12:42:16.940120    6553 x:0] ***************************
I1218 12:42:16.940147    6553 x:0] Args: [/syzkaller/managers/main/current/image -root /syzkaller/managers/main/workdir/gvisor_root -watchdog-action=panic -network=none -debug -alsologtostderr -platform=ptrace -file-access=shared -network=none debug -stacks --ps ci-gvisor-main-2]
I1218 12:42:16.940173    6553 x:0] Version release-20191210.0-47-g64d00cc63dc8
I1218 12:42:16.940179    6553 x:0] PID: 6553
I1218 12:42:16.940186    6553 x:0] UID: 0, GID: 0
I1218 12:42:16.940191    6553 x:0] Configuration:
I1218 12:42:16.940201    6553 x:0] 		RootDir: /syzkaller/managers/main/workdir/gvisor_root
I1218 12:42:16.940205    6553 x:0] 		Platform: ptrace
I1218 12:42:16.940216    6553 x:0] 		FileAccess: shared, overlay: false
I1218 12:42:16.940242    6553 x:0] 		Network: none, logging: false
I1218 12:42:16.940249    6553 x:0] 		Strace: false, max size: 1024, syscalls: []
I1218 12:42:16.940254    6553 x:0] ***************************
D1218 12:42:16.940551    6553 x:0] Load container "/syzkaller/managers/main/workdir/gvisor_root" "ci-gvisor-main-2"
D1218 12:42:16.950600    6553 x:0] Signal container "ci-gvisor-main-2": signal 0
D1218 12:42:16.950627    6553 x:0] Signal sandbox "ci-gvisor-main-2"
D1218 12:42:16.950639    6553 x:0] Connecting to sandbox "ci-gvisor-main-2"
D1218 12:42:16.950874    6553 x:0] urpc: successfully marshalled 96 bytes.
I1218 12:42:17.441020    6553 x:0] Found sandbox "ci-gvisor-main-2", PID: 14319
I1218 12:42:17.441048    6553 x:0] Retrieving sandbox stacks
D1218 12:42:17.441056    6553 x:0] Stacks sandbox "ci-gvisor-main-2"
D1218 12:42:17.441061    6553 x:0] Connecting to sandbox "ci-gvisor-main-2"
D1218 12:42:17.441130    6553 x:0] urpc: successfully marshalled 36 bytes.
W1218 12:42:17.590922    6553 x:0] FATAL ERROR: retrieving stacks: getting sandbox "ci-gvisor-main-2" stacks: urpc method "debug.Stacks" failed: connection reset by peer
retrieving stacks: getting sandbox "ci-gvisor-main-2" stacks: urpc method "debug.Stacks" failed: connection reset by peer
W1218 12:42:17.591046    6553 x:0] Failure to execute command, err: 1