syzbot


DATA RACE in packetmmap.(*Endpoint).ConfigureMMap

Status: fixed on 2025/02/08 00:18
Fix commit: 25084ce9ed1e Add locking around packetmmap initialization and mode.
First crash: 14d, last: 14d

Sample crash report:
WARNING: DATA RACE
Read at 0x00c0003e2b48 by goroutine 388:
  gvisor.dev/gvisor/pkg/sentry/socket/netstack/packetmmap.(*Endpoint).ConfigureMMap()
      pkg/sentry/socket/netstack/packetmmap/endpoint.go:346 +0xdd
  gvisor.dev/gvisor/pkg/sentry/socket/netstack.(*sock).ConfigureMMap()
      pkg/sentry/socket/netstack/netstack.go:3606 +0x17c
  gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).ConfigureMMap()
      pkg/sentry/vfs/file_description.go:710 +0x7c
  gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Mmap()
      pkg/sentry/syscalls/linux/sys_mmap.go:110 +0xb9e
  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 0x00c0003e2b48 by goroutine 386:
  gvisor.dev/gvisor/pkg/sentry/socket/netstack/packetmmap.(*Endpoint).Init()
      pkg/sentry/socket/netstack/packetmmap/endpoint.go:131 +0x968
  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 (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/07 13:33 gvisor 53d6f3dd2a22 a4f327c2 .config console log report syz / log C ci-gvisor-ptrace-1-race-cover DATA RACE in packetmmap.(*Endpoint).ConfigureMMap
2025/02/07 13:00 gvisor 53d6f3dd2a22 a4f327c2 .config console log report syz / log C ci-gvisor-systrap-1-race-cover DATA RACE in packetmmap.(*Endpoint).ConfigureMMap
* Struck through repros no longer work on HEAD.