WARNING: DATA RACE Write at 0x00c000bbc4f8 by goroutine 782: gvisor.dev/gvisor/pkg/sentry/socket/netstack.(*SocketOperations).fetchReadView() pkg/sentry/socket/netstack/netstack.go:418 +0x85 gvisor.dev/gvisor/pkg/sentry/socket/netstack.(*SocketOperations).nonBlockingRead() pkg/sentry/socket/netstack/netstack.go:2388 +0x169 DIAGNOSIS: I0228 22:46:29.036218 7546 main.go:296] *************************** I0228 22:46:29.036354 7546 main.go:297] 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 -alsologtostderr -platform=ptrace -file-access=shared -network=sandbox -TESTONLY-unsafe-nonroot debug -stacks --ps ci-gvisor-ptrace-proxy-sandbox-race-0] I0228 22:46:29.036514 7546 main.go:298] Version release-20200219.0-63-gc96bb4d2ebc6 I0228 22:46:29.036594 7546 main.go:299] PID: 7546 I0228 22:46:29.036670 7546 main.go:300] UID: 0, GID: 0 I0228 22:46:29.036731 7546 main.go:301] Configuration: I0228 22:46:29.036794 7546 main.go:302] RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root I0228 22:46:29.036899 7546 main.go:303] Platform: ptrace I0228 22:46:29.036978 7546 main.go:304] FileAccess: shared, overlay: false I0228 22:46:29.037069 7546 main.go:305] Network: sandbox, logging: false I0228 22:46:29.037146 7546 main.go:306] Strace: false, max size: 1024, syscalls: [] I0228 22:46:29.037250 7546 main.go:307] *************************** W0228 22:46:29.037328 7546 main.go:312] Block the TERM signal. This is only safe in tests! D0228 22:46:29.037483 7546 container.go:159] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-0" D0228 22:46:29.044635 7546 container.go:592] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-0": signal 0 D0228 22:46:29.044823 7546 sandbox.go:788] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0" D0228 22:46:29.044953 7546 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0" D0228 22:46:29.045461 7546 urpc.go:534] urpc: successfully marshalled 117 bytes. I0228 22:46:29.435385 7546 debug.go:122] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0", PID: 63345 I0228 22:46:29.435565 7546 debug.go:131] Retrieving sandbox stacks D0228 22:46:29.435684 7546 sandbox.go:906] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0" D0228 22:46:29.435791 7546 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0" W0228 22:46:29.435960 7546 error.go:48] FATAL ERROR: retrieving stacks: connecting to control server at PID 63345: connection refused retrieving stacks: connecting to control server at PID 63345: connection refused W0228 22:46:29.436236 7546 main.go:329] Failure to execute command, err: 1 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" "-alsologtostderr" "-platform=ptrace" "-file-access=shared" "-network=sandbox" "-TESTONLY-unsafe-nonroot" "debug" "-stacks" "--ps" "ci-gvisor-ptrace-proxy-sandbox-race-0"]: exit status 128 I0228 22:46:29.036218 7546 main.go:296] *************************** I0228 22:46:29.036354 7546 main.go:297] 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 -alsologtostderr -platform=ptrace -file-access=shared -network=sandbox -TESTONLY-unsafe-nonroot debug -stacks --ps ci-gvisor-ptrace-proxy-sandbox-race-0] I0228 22:46:29.036514 7546 main.go:298] Version release-20200219.0-63-gc96bb4d2ebc6 I0228 22:46:29.036594 7546 main.go:299] PID: 7546 I0228 22:46:29.036670 7546 main.go:300] UID: 0, GID: 0 I0228 22:46:29.036731 7546 main.go:301] Configuration: I0228 22:46:29.036794 7546 main.go:302] RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root I0228 22:46:29.036899 7546 main.go:303] Platform: ptrace I0228 22:46:29.036978 7546 main.go:304] FileAccess: shared, overlay: false I0228 22:46:29.037069 7546 main.go:305] Network: sandbox, logging: false I0228 22:46:29.037146 7546 main.go:306] Strace: false, max size: 1024, syscalls: [] I0228 22:46:29.037250 7546 main.go:307] *************************** W0228 22:46:29.037328 7546 main.go:312] Block the TERM signal. This is only safe in tests! D0228 22:46:29.037483 7546 container.go:159] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-0" D0228 22:46:29.044635 7546 container.go:592] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-0": signal 0 D0228 22:46:29.044823 7546 sandbox.go:788] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0" D0228 22:46:29.044953 7546 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0" D0228 22:46:29.045461 7546 urpc.go:534] urpc: successfully marshalled 117 bytes. I0228 22:46:29.435385 7546 debug.go:122] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0", PID: 63345 I0228 22:46:29.435565 7546 debug.go:131] Retrieving sandbox stacks D0228 22:46:29.435684 7546 sandbox.go:906] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0" D0228 22:46:29.435791 7546 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0" W0228 22:46:29.435960 7546 error.go:48] FATAL ERROR: retrieving stacks: connecting to control server at PID 63345: connection refused retrieving stacks: connecting to control server at PID 63345: connection refused W0228 22:46:29.436236 7546 main.go:329] Failure to execute command, err: 1 gvisor.dev/gvisor/pkg/sentry/socket/netstack.(*SocketOperations).RecvMsg() pkg/sentry/socket/netstack/netstack.go:2507 +0x1ad gvisor.dev/gvisor/pkg/sentry/syscalls/linux.recvSingleMsg() pkg/sentry/syscalls/linux/sys_socket.go:783 +0x25a gvisor.dev/gvisor/pkg/sentry/syscalls/linux.RecvMsg() pkg/sentry/syscalls/linux/sys_socket.go:646 +0x291 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall() pkg/sentry/kernel/task_syscall.go:170 +0x455 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke() pkg/sentry/kernel/task_syscall.go:291 +0xb4 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter() pkg/sentry/kernel/task_syscall.go:252 +0x109 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall() pkg/sentry/kernel/task_syscall.go:227 +0x1b3 gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute() pkg/sentry/kernel/task_run.go:232 +0x1aaf gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run() pkg/sentry/kernel/task_run.go:92 +0x308