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-rw-r--r--pkg/sentry/control/BUILD5
-rw-r--r--pkg/sentry/control/proc.go127
2 files changed, 122 insertions, 10 deletions
diff --git a/pkg/sentry/control/BUILD b/pkg/sentry/control/BUILD
index e69496477..d16d78aa5 100644
--- a/pkg/sentry/control/BUILD
+++ b/pkg/sentry/control/BUILD
@@ -16,10 +16,13 @@ go_library(
],
deps = [
"//pkg/abi/linux",
+ "//pkg/context",
"//pkg/fd",
+ "//pkg/fspath",
"//pkg/log",
"//pkg/sentry/fs",
"//pkg/sentry/fs/host",
+ "//pkg/sentry/fsbridge",
"//pkg/sentry/kernel",
"//pkg/sentry/kernel/auth",
"//pkg/sentry/kernel/time",
@@ -27,8 +30,10 @@ go_library(
"//pkg/sentry/state",
"//pkg/sentry/strace",
"//pkg/sentry/usage",
+ "//pkg/sentry/vfs",
"//pkg/sentry/watchdog",
"//pkg/sync",
+ "//pkg/syserror",
"//pkg/tcpip/link/sniffer",
"//pkg/urpc",
],
diff --git a/pkg/sentry/control/proc.go b/pkg/sentry/control/proc.go
index ced51c66c..5457ba5e7 100644
--- a/pkg/sentry/control/proc.go
+++ b/pkg/sentry/control/proc.go
@@ -18,19 +18,26 @@ import (
"bytes"
"encoding/json"
"fmt"
+ "path"
"sort"
"strings"
"text/tabwriter"
"time"
"gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/context"
+ "gvisor.dev/gvisor/pkg/fspath"
+ "gvisor.dev/gvisor/pkg/log"
"gvisor.dev/gvisor/pkg/sentry/fs"
"gvisor.dev/gvisor/pkg/sentry/fs/host"
+ "gvisor.dev/gvisor/pkg/sentry/fsbridge"
"gvisor.dev/gvisor/pkg/sentry/kernel"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
"gvisor.dev/gvisor/pkg/sentry/limits"
"gvisor.dev/gvisor/pkg/sentry/usage"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
"gvisor.dev/gvisor/pkg/urpc"
)
@@ -60,6 +67,12 @@ type ExecArgs struct {
// process's MountNamespace.
MountNamespace *fs.MountNamespace
+ // MountNamespaceVFS2 is the mount namespace to execute the new process in.
+ // A reference on MountNamespace must be held for the lifetime of the
+ // ExecArgs. If MountNamespace is nil, it will default to the init
+ // process's MountNamespace.
+ MountNamespaceVFS2 *vfs.MountNamespace
+
// WorkingDirectory defines the working directory for the new process.
WorkingDirectory string `json:"wd"`
@@ -150,6 +163,7 @@ func (proc *Proc) execAsync(args *ExecArgs) (*kernel.ThreadGroup, kernel.ThreadI
Envv: args.Envv,
WorkingDirectory: args.WorkingDirectory,
MountNamespace: args.MountNamespace,
+ MountNamespaceVFS2: args.MountNamespaceVFS2,
Credentials: creds,
FDTable: fdTable,
Umask: 0022,
@@ -166,24 +180,53 @@ func (proc *Proc) execAsync(args *ExecArgs) (*kernel.ThreadGroup, kernel.ThreadI
// be donated to the new process in CreateProcess.
initArgs.MountNamespace.IncRef()
}
+ if initArgs.MountNamespaceVFS2 != nil {
+ // initArgs must hold a reference on MountNamespaceVFS2, which will
+ // be donated to the new process in CreateProcess.
+ initArgs.MountNamespaceVFS2.IncRef()
+ }
ctx := initArgs.NewContext(proc.Kernel)
if initArgs.Filename == "" {
- // Get the full path to the filename from the PATH env variable.
- paths := fs.GetPath(initArgs.Envv)
- mns := initArgs.MountNamespace
- if mns == nil {
- mns = proc.Kernel.GlobalInit().Leader().MountNamespace()
- }
- f, err := mns.ResolveExecutablePath(ctx, initArgs.WorkingDirectory, initArgs.Argv[0], paths)
- if err != nil {
- return nil, 0, nil, fmt.Errorf("error finding executable %q in PATH %v: %v", initArgs.Argv[0], paths, err)
+ if kernel.VFS2Enabled {
+ // Get the full path to the filename from the PATH env variable.
+ if initArgs.MountNamespaceVFS2 == nil {
+ // Set initArgs so that 'ctx' returns the namespace.
+ //
+ // MountNamespaceVFS2 adds a reference to the namespace, which is
+ // transferred to the new process.
+ initArgs.MountNamespaceVFS2 = proc.Kernel.GlobalInit().Leader().MountNamespaceVFS2()
+ }
+
+ paths := fs.GetPath(initArgs.Envv)
+ vfsObj := proc.Kernel.VFS()
+ file, err := ResolveExecutablePath(ctx, vfsObj, initArgs.WorkingDirectory, initArgs.Argv[0], paths)
+ if err != nil {
+ return nil, 0, nil, fmt.Errorf("error finding executable %q in PATH %v: %v", initArgs.Argv[0], paths, err)
+ }
+ initArgs.File = fsbridge.NewVFSFile(file)
+ } else {
+ // Get the full path to the filename from the PATH env variable.
+ paths := fs.GetPath(initArgs.Envv)
+ if initArgs.MountNamespace == nil {
+ // Set initArgs so that 'ctx' returns the namespace.
+ initArgs.MountNamespace = proc.Kernel.GlobalInit().Leader().MountNamespace()
+
+ // initArgs must hold a reference on MountNamespace, which will
+ // be donated to the new process in CreateProcess.
+ initArgs.MountNamespaceVFS2.IncRef()
+ }
+ f, err := initArgs.MountNamespace.ResolveExecutablePath(ctx, initArgs.WorkingDirectory, initArgs.Argv[0], paths)
+ if err != nil {
+ return nil, 0, nil, fmt.Errorf("error finding executable %q in PATH %v: %v", initArgs.Argv[0], paths, err)
+ }
+ initArgs.Filename = f
}
- initArgs.Filename = f
}
mounter := fs.FileOwnerFromContext(ctx)
+ // TODO(gvisor.dev/issue/1623): Use host FD when supported in VFS2.
var ttyFile *fs.File
for appFD, hostFile := range args.FilePayload.Files {
var appFile *fs.File
@@ -411,3 +454,67 @@ func ttyName(tty *kernel.TTY) string {
}
return fmt.Sprintf("pts/%d", tty.Index)
}
+
+// ResolveExecutablePath resolves the given executable name given a set of
+// paths that might contain it.
+func ResolveExecutablePath(ctx context.Context, vfsObj *vfs.VirtualFilesystem, wd, name string, paths []string) (*vfs.FileDescription, error) {
+ root := vfs.RootFromContext(ctx)
+ defer root.DecRef()
+ creds := auth.CredentialsFromContext(ctx)
+
+ // Absolute paths can be used directly.
+ if path.IsAbs(name) {
+ return openExecutable(ctx, vfsObj, creds, root, name)
+ }
+
+ // Paths with '/' in them should be joined to the working directory, or
+ // to the root if working directory is not set.
+ if strings.IndexByte(name, '/') > 0 {
+ if len(wd) == 0 {
+ wd = "/"
+ }
+ if !path.IsAbs(wd) {
+ return nil, fmt.Errorf("working directory %q must be absolute", wd)
+ }
+ return openExecutable(ctx, vfsObj, creds, root, path.Join(wd, name))
+ }
+
+ // Otherwise, we must lookup the name in the paths, starting from the
+ // calling context's root directory.
+ for _, p := range paths {
+ if !path.IsAbs(p) {
+ // Relative paths aren't safe, no one should be using them.
+ log.Warningf("Skipping relative path %q in $PATH", p)
+ continue
+ }
+
+ binPath := path.Join(p, name)
+ f, err := openExecutable(ctx, vfsObj, creds, root, binPath)
+ if err != nil {
+ return nil, err
+ }
+ if f == nil {
+ continue // Not found/no access.
+ }
+ return f, nil
+ }
+ return nil, syserror.ENOENT
+}
+
+func openExecutable(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials, root vfs.VirtualDentry, path string) (*vfs.FileDescription, error) {
+ pop := vfs.PathOperation{
+ Root: root,
+ Start: root, // binPath is absolute, Start can be anything.
+ Path: fspath.Parse(path),
+ FollowFinalSymlink: true,
+ }
+ opts := &vfs.OpenOptions{
+ Flags: linux.O_RDONLY,
+ FileExec: true,
+ }
+ f, err := vfsObj.OpenAt(ctx, creds, &pop, opts)
+ if err == syserror.ENOENT || err == syserror.EACCES {
+ return nil, nil
+ }
+ return f, err
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 03:26:57 +0000