diff options
Diffstat (limited to 'pkg/sentry/syscalls/linux/sys_thread.go')
| -rw-r--r-- | pkg/sentry/syscalls/linux/sys_thread.go | 43 |
1 files changed, 20 insertions, 23 deletions
diff --git a/pkg/sentry/syscalls/linux/sys_thread.go b/pkg/sentry/syscalls/linux/sys_thread.go index 2476f8858..2d16e4933 100644 --- a/pkg/sentry/syscalls/linux/sys_thread.go +++ b/pkg/sentry/syscalls/linux/sys_thread.go @@ -21,11 +21,12 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" + "gvisor.dev/gvisor/pkg/sentry/fsbridge" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/sched" "gvisor.dev/gvisor/pkg/sentry/loader" - "gvisor.dev/gvisor/pkg/sentry/usermem" "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/usermem" ) const ( @@ -116,10 +117,11 @@ func execveat(t *kernel.Task, dirFD int32, pathnameAddr, argvAddr, envvAddr user resolveFinal := flags&linux.AT_SYMLINK_NOFOLLOW == 0 root := t.FSContext().RootDirectory() - defer root.DecRef() + defer root.DecRef(t) var wd *fs.Dirent - var executable *fs.File + var executable fsbridge.File + var closeOnExec bool if dirFD == linux.AT_FDCWD || path.IsAbs(pathname) { // Even if the pathname is absolute, we may still need the wd // for interpreter scripts if the path of the interpreter is @@ -127,14 +129,23 @@ func execveat(t *kernel.Task, dirFD int32, pathnameAddr, argvAddr, envvAddr user wd = t.FSContext().WorkingDirectory() } else { // Need to extract the given FD. - f := t.GetFile(dirFD) + f, fdFlags := t.FDTable().Get(dirFD) if f == nil { return 0, nil, syserror.EBADF } - defer f.DecRef() + defer f.DecRef(t) + closeOnExec = fdFlags.CloseOnExec if atEmptyPath && len(pathname) == 0 { - executable = f + // TODO(gvisor.dev/issue/160): Linux requires only execute permission, + // not read. However, our backing filesystems may prevent us from reading + // the file without read permission. Additionally, a task with a + // non-readable executable has additional constraints on access via + // ptrace and procfs. + if err := f.Dirent.Inode.CheckPermission(t, fs.PermMask{Read: true, Execute: true}); err != nil { + return 0, nil, err + } + executable = fsbridge.NewFSFile(f) } else { wd = f.Dirent wd.IncRef() @@ -144,19 +155,18 @@ func execveat(t *kernel.Task, dirFD int32, pathnameAddr, argvAddr, envvAddr user } } if wd != nil { - defer wd.DecRef() + defer wd.DecRef(t) } // Load the new TaskContext. remainingTraversals := uint(linux.MaxSymlinkTraversals) loadArgs := loader.LoadArgs{ - Mounts: t.MountNamespace(), - Root: root, - WorkingDirectory: wd, + Opener: fsbridge.NewFSLookup(t.MountNamespace(), root, wd), RemainingTraversals: &remainingTraversals, ResolveFinal: resolveFinal, Filename: pathname, File: executable, + CloseOnExec: closeOnExec, Argv: argv, Envv: envv, Features: t.Arch().FeatureSet(), @@ -217,19 +227,6 @@ func clone(t *kernel.Task, flags int, stack usermem.Addr, parentTID usermem.Addr return uintptr(ntid), ctrl, err } -// Clone implements linux syscall clone(2). -// sys_clone has so many flavors. We implement the default one in linux 3.11 -// x86_64: -// sys_clone(clone_flags, newsp, parent_tidptr, child_tidptr, tls_val) -func Clone(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { - flags := int(args[0].Int()) - stack := args[1].Pointer() - parentTID := args[2].Pointer() - childTID := args[3].Pointer() - tls := args[4].Pointer() - return clone(t, flags, stack, parentTID, childTID, tls) -} - // Fork implements Linux syscall fork(2). func Fork(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { // "A call to fork() is equivalent to a call to clone(2) specifying flags |