syzbot


DATA RACE in packetmmap.(*ringBuffer).internalMappingsForFrame

Status: fixed on 2025/02/08 00:18
Fix commit: da7cd03064d7 Lock around packet mmap fields.
First crash: 14d, last: 14d

Sample crash report:
WARNING: DATA RACE
Read at 0x00c00240c510 by goroutine 35712:
  gvisor.dev/gvisor/pkg/sentry/socket/netstack/packetmmap.(*ringBuffer).internalMappingsForFrame()
      pkg/sentry/socket/netstack/packetmmap/ring_buffer.go:229 +0x105
  gvisor.dev/gvisor/pkg/sentry/socket/netstack/packetmmap.(*ringBuffer).writeStatus()
      pkg/sentry/socket/netstack/packetmmap/ring_buffer.go:134 +0xb0
  gvisor.dev/gvisor/pkg/sentry/socket/netstack/packetmmap.(*Endpoint).HandlePacket()
      pkg/sentry/socket/netstack/packetmmap/endpoint.go:267 +0x90c
  gvisor.dev/gvisor/pkg/tcpip/transport/packet.(*endpoint).HandlePacket()
      pkg/tcpip/transport/packet/endpoint.go:464 +0x139
  gvisor.dev/gvisor/pkg/tcpip/stack.(*nic).DeliverLinkPacket.func2()
      pkg/tcpip/stack/nic.go:815 +0x391
  gvisor.dev/gvisor/pkg/tcpip/stack.(*packetEndpointList).forEach()
      pkg/tcpip/stack/nic.go:146 +0x142
  gvisor.dev/gvisor/pkg/tcpip/stack.(*nic).DeliverLinkPacket()
      pkg/tcpip/stack/nic.go:830 +0x2e6
  gvisor.dev/gvisor/pkg/tcpip/link/nested.(*Endpoint).DeliverLinkPacket()
      pkg/tcpip/link/nested/nested.go:71 +0xc1
  gvisor.dev/gvisor/pkg/tcpip/link/packetsocket.(*endpoint).DeliverNetworkPacket()
      pkg/tcpip/link/packetsocket/packetsocket.go:45 +0x4b
  gvisor.dev/gvisor/pkg/tcpip/link/channel.(*Endpoint).InjectInbound()
      pkg/tcpip/link/channel/channel.go:208 +0xc1
  gvisor.dev/gvisor/pkg/tcpip/link/tun.(*Device).Write()
      pkg/tcpip/link/tun/device.go:250 +0x805
  gvisor.dev/gvisor/pkg/sentry/devices/tundev.(*tunFD).Write()
      pkg/sentry/devices/tundev/tundev.go:163 +0x591
  gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Write()
      pkg/sentry/vfs/file_description.go:682 +0x144
  gvisor.dev/gvisor/pkg/sentry/syscalls/linux.write()
      pkg/sentry/syscalls/linux/sys_read_write.go:347 +0xa4
  gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Write()
      pkg/sentry/syscalls/linux/sys_read_write.go:316 +0x38e
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall()
      pkg/sentry/kernel/task_syscall.go:143 +0xb9e
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke()
      pkg/sentry/kernel/task_syscall.go:323 +0x84
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter()
      pkg/sentry/kernel/task_syscall.go:283 +0xc6
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall()
      pkg/sentry/kernel/task_syscall.go:258 +0x549
  gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute()
      pkg/sentry/kernel/task_run.go:269 +0x2294
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run()
      pkg/sentry/kernel/task_run.go:97 +0x41a
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.gowrap1()
      pkg/sentry/kernel/task_start.go:412 +0x44

Previous write at 0x00c00240c510 by goroutine 35710:
  gvisor.dev/gvisor/pkg/sentry/socket/netstack/packetmmap.(*ringBuffer).init()
      pkg/sentry/socket/netstack/packetmmap/ring_buffer.go:62 +0xf9
  gvisor.dev/gvisor/pkg/sentry/socket/netstack/packetmmap.(*Endpoint).Init()
      pkg/sentry/socket/netstack/packetmmap/endpoint.go:128 +0x912
  gvisor.dev/gvisor/pkg/sentry/socket/netstack.setSockOptPacket()
      pkg/sentry/socket/netstack/netstack.go:2749 +0x734
  gvisor.dev/gvisor/pkg/sentry/socket/netstack.SetSockOpt()
      pkg/sentry/socket/netstack/netstack.go:1873 +0x365
  gvisor.dev/gvisor/pkg/sentry/socket/netstack.(*sock).SetSockOpt()
      pkg/sentry/socket/netstack/netstack.go:634 +0x6a9
  gvisor.dev/gvisor/pkg/sentry/syscalls/linux.SetSockOpt()
      pkg/sentry/syscalls/linux/sys_socket.go:551 +0x46b
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall()
      pkg/sentry/kernel/task_syscall.go:143 +0xb9e
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke()
      pkg/sentry/kernel/task_syscall.go:323 +0x84
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter()
      pkg/sentry/kernel/task_syscall.go:283 +0xc6
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall()
      pkg/sentry/kernel/task_syscall.go:258 +0x549
  gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute()
      pkg/sentry/kernel/task_run.go:269 +0x2294
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run()
      pkg/sentry/kernel/task_run.go:97 +0x41a
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.gowrap1()
      pkg/sentry/kernel/task_start.go:412 +0x44

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/07 09:02 gvisor a4a0e84b5cd5 53657d1b .config console log report info ci-gvisor-systrap-1-race-cover DATA RACE in packetmmap.(*ringBuffer).internalMappingsForFrame
* Struck through repros no longer work on HEAD.