diff options
Diffstat (limited to 'internal/app/setuid/process.go')
| -rw-r--r-- | internal/app/setuid/process.go | 195 |
1 files changed, 0 insertions, 195 deletions
diff --git a/internal/app/setuid/process.go b/internal/app/setuid/process.go deleted file mode 100644 index e730225e..00000000 --- a/internal/app/setuid/process.go +++ /dev/null @@ -1,195 +0,0 @@ -package setuid - -import ( - "context" - "encoding/gob" - "errors" - "log" - "os" - "os/exec" - "strconv" - "strings" - "syscall" - "time" - - "git.gensokyo.uk/security/fortify/fst" - "git.gensokyo.uk/security/fortify/internal" - "git.gensokyo.uk/security/fortify/internal/fmsg" - "git.gensokyo.uk/security/fortify/internal/state" - "git.gensokyo.uk/security/fortify/sandbox" - "git.gensokyo.uk/security/fortify/system" -) - -const shimWaitTimeout = 5 * time.Second - -func (seal *outcome) Run(rs *fst.RunState) error { - if !seal.f.CompareAndSwap(false, true) { - // run does much more than just starting a process; calling it twice, even if the first call fails, will result - // in inconsistent state that is impossible to clean up; return here to limit damage and hopefully give the - // other Run a chance to return - return errors.New("outcome: attempted to run twice") - } - - if rs == nil { - panic("invalid state") - } - - // read comp value early to allow for early failure - fsuPath := internal.MustFsuPath() - - if err := seal.sys.Commit(seal.ctx); err != nil { - return err - } - store := state.NewMulti(seal.runDirPath) - deferredStoreFunc := func(c state.Cursor) error { return nil } // noop until state in store - defer func() { - var revertErr error - storeErr := new(StateStoreError) - storeErr.Inner, storeErr.DoErr = store.Do(seal.user.aid.unwrap(), func(c state.Cursor) { - revertErr = func() error { - storeErr.InnerErr = deferredStoreFunc(c) - - var rt system.Enablement - ec := system.Process - if states, err := c.Load(); err != nil { - // revert per-process state here to limit damage - storeErr.OpErr = err - return seal.sys.Revert((*system.Criteria)(&ec)) - } else { - if l := len(states); l == 0 { - ec |= system.User - } else { - fmsg.Verbosef("found %d instances, cleaning up without user-scoped operations", l) - } - - // accumulate enablements of remaining launchers - for i, s := range states { - if s.Config != nil { - rt |= s.Config.Confinement.Enablements - } else { - log.Printf("state entry %d does not contain config", i) - } - } - } - ec |= rt ^ (system.EWayland | system.EX11 | system.EDBus | system.EPulse) - if fmsg.Load() { - if ec > 0 { - fmsg.Verbose("reverting operations scope", system.TypeString(ec)) - } - } - - return seal.sys.Revert((*system.Criteria)(&ec)) - }() - }) - storeErr.save(revertErr, store.Close()) - rs.RevertErr = storeErr.equiv("error during cleanup:") - }() - - ctx, cancel := context.WithCancel(seal.ctx) - defer cancel() - cmd := exec.CommandContext(ctx, fsuPath) - cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr - cmd.Dir = "/" // container init enters final working directory - // shim runs in the same session as monitor; see shim.go for behaviour - cmd.Cancel = func() error { return cmd.Process.Signal(syscall.SIGCONT) } - - var e *gob.Encoder - if fd, encoder, err := sandbox.Setup(&cmd.ExtraFiles); err != nil { - return fmsg.WrapErrorSuffix(err, - "cannot create shim setup pipe:") - } else { - e = encoder - cmd.Env = []string{ - // passed through to shim by fsu - shimEnv + "=" + strconv.Itoa(fd), - // interpreted by fsu - "FORTIFY_APP_ID=" + seal.user.aid.String(), - } - } - - if len(seal.user.supp) > 0 { - fmsg.Verbosef("attaching supplementary group ids %s", seal.user.supp) - // interpreted by fsu - cmd.Env = append(cmd.Env, "FORTIFY_GROUPS="+strings.Join(seal.user.supp, " ")) - } - - fmsg.Verbosef("setuid helper at %s", fsuPath) - fmsg.Suspend() - if err := cmd.Start(); err != nil { - return fmsg.WrapErrorSuffix(err, - "cannot start setuid wrapper:") - } - rs.SetStart() - - // this prevents blocking forever on an early failure - waitErr, setupErr := make(chan error, 1), make(chan error, 1) - go func() { waitErr <- cmd.Wait(); cancel() }() - go func() { setupErr <- e.Encode(&shimParams{os.Getpid(), seal.container, seal.user.data, fmsg.Load()}) }() - - select { - case err := <-setupErr: - if err != nil { - fmsg.Resume() - return fmsg.WrapErrorSuffix(err, - "cannot transmit shim config:") - } - - case <-ctx.Done(): - fmsg.Resume() - return fmsg.WrapError(syscall.ECANCELED, - "shim setup canceled") - } - - // returned after blocking on waitErr - var earlyStoreErr = new(StateStoreError) - { - // shim accepted setup payload, create process state - sd := state.State{ - ID: seal.id.unwrap(), - PID: cmd.Process.Pid, - Time: *rs.Time, - } - earlyStoreErr.Inner, earlyStoreErr.DoErr = store.Do(seal.user.aid.unwrap(), func(c state.Cursor) { - earlyStoreErr.InnerErr = c.Save(&sd, seal.ct) - }) - } - - // state in store at this point, destroy defunct state entry on return - deferredStoreFunc = func(c state.Cursor) error { return c.Destroy(seal.id.unwrap()) } - - waitTimeout := make(chan struct{}) - go func() { <-seal.ctx.Done(); time.Sleep(shimWaitTimeout); close(waitTimeout) }() - - select { - case rs.WaitErr = <-waitErr: - rs.WaitStatus = cmd.ProcessState.Sys().(syscall.WaitStatus) - if fmsg.Load() { - switch { - case rs.Exited(): - fmsg.Verbosef("process %d exited with code %d", cmd.Process.Pid, rs.ExitStatus()) - case rs.CoreDump(): - fmsg.Verbosef("process %d dumped core", cmd.Process.Pid) - case rs.Signaled(): - fmsg.Verbosef("process %d got %s", cmd.Process.Pid, rs.Signal()) - default: - fmsg.Verbosef("process %d exited with status %#x", cmd.Process.Pid, rs.WaitStatus) - } - } - case <-waitTimeout: - rs.WaitErr = syscall.ETIMEDOUT - fmsg.Resume() - log.Printf("process %d did not terminate", cmd.Process.Pid) - } - - fmsg.Resume() - if seal.sync != nil { - if err := seal.sync.Close(); err != nil { - log.Printf("cannot close wayland security context: %v", err) - } - } - if seal.dbusMsg != nil { - seal.dbusMsg() - } - - return earlyStoreErr.equiv("cannot save process state:") -} |
