diff options
| author | Dean Deng <deandeng@google.com> | 2019-10-29 10:03:18 -0700 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2019-10-29 10:04:39 -0700 |
| commit | 29273b03842a85bce8314799348231520ceb6e9c (patch) | |
| tree | 118b42eb7eb8ef0f6942ca75f1575de1fdf272ee /pkg/sentry/syscalls/linux | |
| parent | dbeaf9d4dbeea4cde670c3d07a78b56a45fa8f21 (diff) | |
Disallow execveat on interpreter scripts with fd opened with O_CLOEXEC.
When an interpreter script is opened with O_CLOEXEC and the resulting fd is
passed into execveat, an ENOENT error should occur (the script would otherwise
be inaccessible to the interpreter). This matches the actual behavior of
Linux's execveat.
PiperOrigin-RevId: 277306680
Diffstat (limited to 'pkg/sentry/syscalls/linux')
| -rw-r--r-- | pkg/sentry/syscalls/linux/sys_thread.go | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/pkg/sentry/syscalls/linux/sys_thread.go b/pkg/sentry/syscalls/linux/sys_thread.go index 2476f8858..4115116ff 100644 --- a/pkg/sentry/syscalls/linux/sys_thread.go +++ b/pkg/sentry/syscalls/linux/sys_thread.go @@ -120,6 +120,7 @@ func execveat(t *kernel.Task, dirFD int32, pathnameAddr, argvAddr, envvAddr user var wd *fs.Dirent var executable *fs.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 @@ -127,11 +128,12 @@ 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() + closeOnExec = fdFlags.CloseOnExec if atEmptyPath && len(pathname) == 0 { executable = f @@ -157,6 +159,7 @@ func execveat(t *kernel.Task, dirFD int32, pathnameAddr, argvAddr, envvAddr user ResolveFinal: resolveFinal, Filename: pathname, File: executable, + CloseOnExec: closeOnExec, Argv: argv, Envv: envv, Features: t.Arch().FeatureSet(), |