dracut-install: preserve extended attributes when copying files

Preserve extended attributes when copying files using dracut-install.

The copying of extended attributes avoids file execution denials when
the Linux Integrity Measurement's Appraisal mode is active. In that mode
executables need their file signatures copied. In particular, this patch
solves the problem that dependent libaries are not included in the
initramfs since the copied programs could not be executed due to missing
signatures. The following audit record shows the type of failure that
is now prevented:

type=INTEGRITY_DATA msg=audit(1477409025.492:30065): pid=922 uid=0
 auid=4294967295 ses=4294967295
 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
 op="appraise_data" cause="IMA-signature-required"
 comm="ld-linux-x86-64"
 name="/var/tmp/dracut.R6ySa4/initramfs/usr/bin/journalctl"
 dev="dm-0" ino=37136 res=0

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>

diff --git a/install/dracut-install.c b/install/dracut-install.c
index fe30bbac0c5c76d0f0a197b9164217c54e7a61fa..c0f1c17c774f54bf0e90957d577514e3763da65e 100644 (file)
--- a/install/dracut-install.c
+++ b/install/dracut-install.c
@@ -294,7 +294,7 @@ static int cp(const char *src, const char *dst)
  normal_copy:
         pid = fork();
         if (pid == 0) {
-                execlp("cp", "cp", "--reflink=auto", "--sparse=auto", "--preserve=mode,timestamps", "-fL", src, dst,
+                execlp("cp", "cp", "--reflink=auto", "--sparse=auto", "--preserve=mode,timestamps,xattr", "-fL", src, dst,
                        NULL);
                 _exit(EXIT_FAILURE);
         }
@@ -302,7 +302,7 @@ static int cp(const char *src, const char *dst)
         while (waitpid(pid, &ret, 0) < 0) {
                 if (errno != EINTR) {
                         ret = -1;
-                        log_error("Failed: cp --reflink=auto --sparse=auto --preserve=mode,timestamps -fL %s %s", src,
+                        log_error("Failed: cp --reflink=auto --sparse=auto --preserve=mode,timestamps,xattr -fL %s %s", src,
                                   dst);
                         break;
                 }