diff options
author | gVisor bot <gvisor-bot@google.com> | 2020-05-29 23:38:33 +0000 |
---|---|---|
committer | gVisor bot <gvisor-bot@google.com> | 2020-05-29 23:38:33 +0000 |
commit | 61a2e099bdf83463ec0055e1f82a4b483adee0eb (patch) | |
tree | 63527db3ccb38e4c3fb9594d7c9a6bb0b844ffc2 | |
parent | 1ca003b78a6e1c633f5112b58f4ec81cf445afdf (diff) | |
parent | 93edb36cbb653f8415d5c813e40ef21fed123417 (diff) |
Merge release-20200522.0-43-g93edb36c (automated)
-rw-r--r-- | pkg/abi/linux/linux_abi_autogen_unsafe.go | 6 | ||||
-rw-r--r-- | pkg/sentry/control/proc.go | 68 | ||||
-rw-r--r-- | pkg/sentry/fs/mounts.go | 72 | ||||
-rw-r--r-- | pkg/sentry/fs/user/path.go | 169 | ||||
-rw-r--r-- | pkg/sentry/fs/user/user.go | 2 | ||||
-rw-r--r-- | runsc/boot/fs.go | 14 | ||||
-rw-r--r-- | runsc/boot/vfs.go | 76 |
7 files changed, 201 insertions, 206 deletions
diff --git a/pkg/abi/linux/linux_abi_autogen_unsafe.go b/pkg/abi/linux/linux_abi_autogen_unsafe.go index fe2419912..6bf2e1a64 100644 --- a/pkg/abi/linux/linux_abi_autogen_unsafe.go +++ b/pkg/abi/linux/linux_abi_autogen_unsafe.go @@ -124,12 +124,12 @@ func (s *Statx) UnmarshalBytes(src []byte) { // Packed implements marshal.Marshallable.Packed. //go:nosplit func (s *Statx) Packed() bool { - return s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() + return s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() } // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. func (s *Statx) MarshalUnsafe(dst []byte) { - if s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() { + if s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() { safecopy.CopyIn(dst, unsafe.Pointer(s)) } else { s.MarshalBytes(dst) @@ -178,7 +178,7 @@ func (s *Statx) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) { // CopyIn implements marshal.Marshallable.CopyIn. //go:nosplit func (s *Statx) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) { - if !s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() { + if !s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() { // Type Statx doesn't have a packed layout in memory, fall back to UnmarshalBytes. buf := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay. length, err := task.CopyInBytes(addr, buf) // escapes: okay. diff --git a/pkg/sentry/control/proc.go b/pkg/sentry/control/proc.go index 2ed17ee09..8767430b7 100644 --- a/pkg/sentry/control/proc.go +++ b/pkg/sentry/control/proc.go @@ -18,7 +18,6 @@ import ( "bytes" "encoding/json" "fmt" - "path" "sort" "strings" "text/tabwriter" @@ -28,10 +27,10 @@ import ( "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/fdimport" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/host" + "gvisor.dev/gvisor/pkg/sentry/fs/user" "gvisor.dev/gvisor/pkg/sentry/fsbridge" hostvfs2 "gvisor.dev/gvisor/pkg/sentry/fsimpl/host" "gvisor.dev/gvisor/pkg/sentry/kernel" @@ -190,17 +189,12 @@ func (proc *Proc) execAsync(args *ExecArgs) (*kernel.ThreadGroup, kernel.ThreadI // 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) + file, err := getExecutableFD(ctx, creds, proc.Kernel.VFS(), initArgs.MountNamespaceVFS2, initArgs.Envv, initArgs.WorkingDirectory, initArgs.Argv[0]) if err != nil { - return nil, 0, nil, nil, fmt.Errorf("error finding executable %q in PATH %v: %v", initArgs.Argv[0], paths, err) + return nil, 0, nil, nil, fmt.Errorf("error finding executable %q in environment %v: %v", initArgs.Argv[0], initArgs.Envv, 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() @@ -209,9 +203,9 @@ func (proc *Proc) execAsync(args *ExecArgs) (*kernel.ThreadGroup, kernel.ThreadI // be donated to the new process in CreateProcess. initArgs.MountNamespace.IncRef() } - f, err := initArgs.MountNamespace.ResolveExecutablePath(ctx, initArgs.WorkingDirectory, initArgs.Argv[0], paths) + f, err := user.ResolveExecutablePath(ctx, creds, initArgs.MountNamespace, initArgs.Envv, initArgs.WorkingDirectory, initArgs.Argv[0]) if err != nil { - return nil, 0, nil, nil, fmt.Errorf("error finding executable %q in PATH %v: %v", initArgs.Argv[0], paths, err) + return nil, 0, nil, nil, fmt.Errorf("error finding executable %q in PATH %v: %v", initArgs.Argv[0], initArgs.Envv, err) } initArgs.Filename = f } @@ -429,53 +423,17 @@ 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)) +// getExecutableFD resolves the given executable name and returns a +// vfs.FileDescription for the executable file. +func getExecutableFD(ctx context.Context, creds *auth.Credentials, vfsObj *vfs.VirtualFilesystem, mns *vfs.MountNamespace, envv []string, wd, name string) (*vfs.FileDescription, error) { + path, err := user.ResolveExecutablePathVFS2(ctx, creds, mns, envv, wd, name) + if err != nil { + return nil, err } - // 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 -} + root := vfs.RootFromContext(ctx) + defer root.DecRef() -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. diff --git a/pkg/sentry/fs/mounts.go b/pkg/sentry/fs/mounts.go index b414ddaee..3f2bd0e87 100644 --- a/pkg/sentry/fs/mounts.go +++ b/pkg/sentry/fs/mounts.go @@ -17,13 +17,9 @@ package fs import ( "fmt" "math" - "path" - "strings" "syscall" - "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/refs" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sync" @@ -625,71 +621,3 @@ func (mns *MountNamespace) SyncAll(ctx context.Context) { defer mns.mu.Unlock() mns.root.SyncAll(ctx) } - -// ResolveExecutablePath resolves the given executable name given a set of -// paths that might contain it. -func (mns *MountNamespace) ResolveExecutablePath(ctx context.Context, wd, name string, paths []string) (string, error) { - // Absolute paths can be used directly. - if path.IsAbs(name) { - return name, nil - } - - // 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 wd == "" { - wd = "/" - } - if !path.IsAbs(wd) { - return "", fmt.Errorf("working directory %q must be absolute", wd) - } - return path.Join(wd, name), nil - } - - // Otherwise, We must lookup the name in the paths, starting from the - // calling context's root directory. - root := RootFromContext(ctx) - if root == nil { - // Caller has no root. Don't bother traversing anything. - return "", syserror.ENOENT - } - defer root.DecRef() - for _, p := range paths { - binPath := path.Join(p, name) - traversals := uint(linux.MaxSymlinkTraversals) - d, err := mns.FindInode(ctx, root, nil, binPath, &traversals) - if err == syserror.ENOENT || err == syserror.EACCES { - // Didn't find it here. - continue - } - if err != nil { - return "", err - } - defer d.DecRef() - - // Check that it is a regular file. - if !IsRegular(d.Inode.StableAttr) { - continue - } - - // Check whether we can read and execute the found file. - if err := d.Inode.CheckPermission(ctx, PermMask{Read: true, Execute: true}); err != nil { - log.Infof("Found executable at %q, but user cannot execute it: %v", binPath, err) - continue - } - return path.Join("/", p, name), nil - } - return "", syserror.ENOENT -} - -// GetPath returns the PATH as a slice of strings given the environment -// variables. -func GetPath(env []string) []string { - const prefix = "PATH=" - for _, e := range env { - if strings.HasPrefix(e, prefix) { - return strings.Split(strings.TrimPrefix(e, prefix), ":") - } - } - return nil -} diff --git a/pkg/sentry/fs/user/path.go b/pkg/sentry/fs/user/path.go new file mode 100644 index 000000000..fbd4547a7 --- /dev/null +++ b/pkg/sentry/fs/user/path.go @@ -0,0 +1,169 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package user + +import ( + "fmt" + "path" + "strings" + + "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/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserror" +) + +// ResolveExecutablePath resolves the given executable name given the working +// dir and environment. +func ResolveExecutablePath(ctx context.Context, creds *auth.Credentials, mns *fs.MountNamespace, envv []string, wd, name string) (string, error) { + // Absolute paths can be used directly. + if path.IsAbs(name) { + return name, nil + } + + // 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 wd == "" { + wd = "/" + } + if !path.IsAbs(wd) { + return "", fmt.Errorf("working directory %q must be absolute", wd) + } + return path.Join(wd, name), nil + } + + // Otherwise, We must lookup the name in the paths, starting from the + // calling context's root directory. + paths := getPath(envv) + + root := fs.RootFromContext(ctx) + if root == nil { + // Caller has no root. Don't bother traversing anything. + return "", syserror.ENOENT + } + defer root.DecRef() + 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) + traversals := uint(linux.MaxSymlinkTraversals) + d, err := mns.FindInode(ctx, root, nil, binPath, &traversals) + if err == syserror.ENOENT || err == syserror.EACCES { + // Didn't find it here. + continue + } + if err != nil { + return "", err + } + defer d.DecRef() + + // Check that it is a regular file. + if !fs.IsRegular(d.Inode.StableAttr) { + continue + } + + // Check whether we can read and execute the found file. + if err := d.Inode.CheckPermission(ctx, fs.PermMask{Read: true, Execute: true}); err != nil { + log.Infof("Found executable at %q, but user cannot execute it: %v", binPath, err) + continue + } + return path.Join("/", p, name), nil + } + + // Couldn't find it. + return "", syserror.ENOENT +} + +// ResolveExecutablePathVFS2 resolves the given executable name given the +// working dir and environment. +func ResolveExecutablePathVFS2(ctx context.Context, creds *auth.Credentials, mns *vfs.MountNamespace, envv []string, wd, name string) (string, error) { + // Absolute paths can be used directly. + if path.IsAbs(name) { + return name, nil + } + + // 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 wd == "" { + wd = "/" + } + if !path.IsAbs(wd) { + return "", fmt.Errorf("working directory %q must be absolute", wd) + } + return path.Join(wd, name), nil + } + + // Otherwise, We must lookup the name in the paths, starting from the + // calling context's root directory. + paths := getPath(envv) + + root := mns.Root() + defer root.DecRef() + 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) + pop := &vfs.PathOperation{ + Root: root, + Start: root, + Path: fspath.Parse(binPath), + FollowFinalSymlink: true, + } + opts := &vfs.OpenOptions{ + FileExec: true, + Flags: linux.O_RDONLY, + } + dentry, err := root.Mount().Filesystem().VirtualFilesystem().OpenAt(ctx, creds, pop, opts) + if err == syserror.ENOENT || err == syserror.EACCES { + // Didn't find it here. + continue + } + if err != nil { + return "", err + } + dentry.DecRef() + + return binPath, nil + } + + // Couldn't find it. + return "", syserror.ENOENT +} + +// getPath returns the PATH as a slice of strings given the environment +// variables. +func getPath(env []string) []string { + const prefix = "PATH=" + for _, e := range env { + if strings.HasPrefix(e, prefix) { + return strings.Split(strings.TrimPrefix(e, prefix), ":") + } + } + return nil +} diff --git a/pkg/sentry/fs/user/user.go b/pkg/sentry/fs/user/user.go index fe7f67c00..f4d525523 100644 --- a/pkg/sentry/fs/user/user.go +++ b/pkg/sentry/fs/user/user.go @@ -12,6 +12,8 @@ // See the License for the specific language governing permissions and // limitations under the License. +// Package user contains methods for resolving filesystem paths based on the +// user and their environment. package user import ( diff --git a/runsc/boot/fs.go b/runsc/boot/fs.go index 9cd4f97da..52f8344ca 100644 --- a/runsc/boot/fs.go +++ b/runsc/boot/fs.go @@ -37,6 +37,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/gofer" "gvisor.dev/gvisor/pkg/sentry/fs/ramfs" + "gvisor.dev/gvisor/pkg/sentry/fs/user" "gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts" "gvisor.dev/gvisor/pkg/sentry/fsimpl/devtmpfs" gofervfs2 "gvisor.dev/gvisor/pkg/sentry/fsimpl/gofer" @@ -291,17 +292,10 @@ func setupContainerFS(ctx context.Context, conf *Config, mntr *containerMounter, // Set namespace here so that it can be found in ctx. procArgs.MountNamespace = mns - return setExecutablePath(ctx, procArgs) -} - -// setExecutablePath sets the procArgs.Filename by searching the PATH for an -// executable matching the procArgs.Argv[0]. -func setExecutablePath(ctx context.Context, procArgs *kernel.CreateProcessArgs) error { - paths := fs.GetPath(procArgs.Envv) - exe := procArgs.Argv[0] - f, err := procArgs.MountNamespace.ResolveExecutablePath(ctx, procArgs.WorkingDirectory, exe, paths) + // Resolve the executable path from working dir and environment. + f, err := user.ResolveExecutablePath(ctx, procArgs.Credentials, procArgs.MountNamespace, procArgs.Envv, procArgs.WorkingDirectory, procArgs.Argv[0]) if err != nil { - return fmt.Errorf("searching for executable %q, cwd: %q, $PATH=%q: %v", exe, procArgs.WorkingDirectory, strings.Join(paths, ":"), err) + return fmt.Errorf("searching for executable %q, cwd: %q, envv: %q: %v", procArgs.Argv[0], procArgs.WorkingDirectory, procArgs.Envv, err) } procArgs.Filename = f return nil diff --git a/runsc/boot/vfs.go b/runsc/boot/vfs.go index fefeeff58..f48e6b0f1 100644 --- a/runsc/boot/vfs.go +++ b/runsc/boot/vfs.go @@ -22,22 +22,21 @@ import ( specs "github.com/opencontainers/runtime-spec/specs-go" "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/devices/memdev" - "gvisor.dev/gvisor/pkg/sentry/fs" + "gvisor.dev/gvisor/pkg/sentry/fs/user" "gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts" "gvisor.dev/gvisor/pkg/sentry/fsimpl/devtmpfs" "gvisor.dev/gvisor/pkg/sentry/fsimpl/gofer" "gvisor.dev/gvisor/pkg/sentry/fsimpl/proc" "gvisor.dev/gvisor/pkg/sentry/fsimpl/sys" "gvisor.dev/gvisor/pkg/sentry/fsimpl/tmpfs" - "gvisor.dev/gvisor/pkg/syserror" - - "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserror" ) func registerFilesystems(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials) error { @@ -95,69 +94,14 @@ func setupContainerVFS2(ctx context.Context, conf *Config, mntr *containerMounte return fmt.Errorf("failed to setupFS: %w", err) } procArgs.MountNamespaceVFS2 = mns - return setExecutablePathVFS2(ctx, procArgs) -} - -func setExecutablePathVFS2(ctx context.Context, procArgs *kernel.CreateProcessArgs) error { - exe := procArgs.Argv[0] - // Absolute paths can be used directly. - if path.IsAbs(exe) { - procArgs.Filename = exe - return nil - } - - // Paths with '/' in them should be joined to the working directory, or - // to the root if working directory is not set. - if strings.IndexByte(exe, '/') > 0 { - if !path.IsAbs(procArgs.WorkingDirectory) { - return fmt.Errorf("working directory %q must be absolute", procArgs.WorkingDirectory) - } - procArgs.Filename = path.Join(procArgs.WorkingDirectory, exe) - return nil - } - - // Paths with a '/' are relative to the CWD. - if strings.IndexByte(exe, '/') > 0 { - procArgs.Filename = path.Join(procArgs.WorkingDirectory, exe) - return nil - } - - // Otherwise, We must lookup the name in the paths, starting from the - // root directory. - root := procArgs.MountNamespaceVFS2.Root() - defer root.DecRef() - - paths := fs.GetPath(procArgs.Envv) - creds := procArgs.Credentials - - for _, p := range paths { - binPath := path.Join(p, exe) - pop := &vfs.PathOperation{ - Root: root, - Start: root, - Path: fspath.Parse(binPath), - FollowFinalSymlink: true, - } - opts := &vfs.OpenOptions{ - FileExec: true, - Flags: linux.O_RDONLY, - } - dentry, err := root.Mount().Filesystem().VirtualFilesystem().OpenAt(ctx, creds, pop, opts) - if err == syserror.ENOENT || err == syserror.EACCES { - // Didn't find it here. - continue - } - if err != nil { - return err - } - dentry.DecRef() - - procArgs.Filename = binPath - return nil + // Resolve the executable path from working dir and environment. + f, err := user.ResolveExecutablePathVFS2(ctx, procArgs.Credentials, procArgs.MountNamespaceVFS2, procArgs.Envv, procArgs.WorkingDirectory, procArgs.Argv[0]) + if err != nil { + return fmt.Errorf("searching for executable %q, cwd: %q, envv: %q: %v", procArgs.Argv[0], procArgs.WorkingDirectory, procArgs.Envv, err) } - - return fmt.Errorf("executable %q not found in $PATH=%q", exe, strings.Join(paths, ":")) + procArgs.Filename = f + return nil } func (c *containerMounter) setupVFS2(ctx context.Context, conf *Config, procArgs *kernel.CreateProcessArgs) (*vfs.MountNamespace, error) { |