diff options
Diffstat (limited to 'pkg/sentry/vfs')
-rwxr-xr-x | pkg/sentry/vfs/options.go | 5 | ||||
-rwxr-xr-x | pkg/sentry/vfs/permissions.go | 19 | ||||
-rwxr-xr-x | pkg/sentry/vfs/vfs.go | 19 |
3 files changed, 36 insertions, 7 deletions
diff --git a/pkg/sentry/vfs/options.go b/pkg/sentry/vfs/options.go index b7774bf28..fdf8be157 100755 --- a/pkg/sentry/vfs/options.go +++ b/pkg/sentry/vfs/options.go @@ -72,6 +72,11 @@ type OpenOptions struct { // If FilesystemImpl.OpenAt() creates a file, Mode is the file mode for the // created file. Mode linux.FileMode + + // FileExec is set when the file is being opened to be executed. + // VirtualFilesystem.OpenAt() checks that the caller has execute permissions + // on the file, and that the file is a regular file. + FileExec bool } // ReadOptions contains options to FileDescription.PRead(), diff --git a/pkg/sentry/vfs/permissions.go b/pkg/sentry/vfs/permissions.go index f664581f4..8e250998a 100755 --- a/pkg/sentry/vfs/permissions.go +++ b/pkg/sentry/vfs/permissions.go @@ -103,17 +103,22 @@ func GenericCheckPermissions(creds *auth.Credentials, ats AccessTypes, isDir boo // AccessTypesForOpenFlags returns MayRead|MayWrite in this case. // // Use May{Read,Write}FileWithOpenFlags() for these checks instead. -func AccessTypesForOpenFlags(flags uint32) AccessTypes { - switch flags & linux.O_ACCMODE { +func AccessTypesForOpenFlags(opts *OpenOptions) AccessTypes { + ats := AccessTypes(0) + if opts.FileExec { + ats |= MayExec + } + + switch opts.Flags & linux.O_ACCMODE { case linux.O_RDONLY: - if flags&linux.O_TRUNC != 0 { - return MayRead | MayWrite + if opts.Flags&linux.O_TRUNC != 0 { + return ats | MayRead | MayWrite } - return MayRead + return ats | MayRead case linux.O_WRONLY: - return MayWrite + return ats | MayWrite default: - return MayRead | MayWrite + return ats | MayRead | MayWrite } } diff --git a/pkg/sentry/vfs/vfs.go b/pkg/sentry/vfs/vfs.go index 908c69f91..9629afee9 100755 --- a/pkg/sentry/vfs/vfs.go +++ b/pkg/sentry/vfs/vfs.go @@ -379,6 +379,25 @@ func (vfs *VirtualFilesystem) OpenAt(ctx context.Context, creds *auth.Credential fd, err := rp.mount.fs.impl.OpenAt(ctx, rp, *opts) if err == nil { vfs.putResolvingPath(rp) + + // TODO(gvisor.dev/issue/1193): Move inside fsimpl to avoid another call + // to FileDescription.Stat(). + if opts.FileExec { + // Only a regular file can be executed. + stat, err := fd.Stat(ctx, StatOptions{Mask: linux.STATX_TYPE}) + if err != nil { + return nil, err + } + if stat.Mask&linux.STATX_TYPE != 0 { + // This shouldn't happen, but if type can't be retrieved, file can't + // be executed. + return nil, syserror.EACCES + } + if linux.FileMode(stat.Mode).FileType() != linux.ModeRegular { + return nil, syserror.EACCES + } + } + return fd, nil } if !rp.handleError(err) { |