virt-aa-helper: resolve file symlinks

In a recent change b932ed69: "virt-aa-helper: resolve yet to be created
paths" several cases with symlinks in paths were fixed, but it regressed
cases where the file being last element of the path was the actual link.

In the case of the last element being the symlink realpath can (and shall)
be called on the full path that was passed.

Examples would be zfs/lvm block devices like:
 <disk type='block' device='disk'>
    <driver name='qemu' type='raw'/>
    <source dev='/dev/mapper/testlvm-testvol1'/>
    <target dev='vdd' bus='virtio'/>
 </disk>
With the target being:
 /dev/mapper/testlvm-testvol1 -> ../dm-0

That currently is rendered as
 "/dev/mapper/testlvm-testvol1" rwk,
but instead should be (and is with the fix):
 "/dev/dm-0" rwk,

Fixes: b932ed69: "virt-aa-helper: resolve yet to be created paths"
Fixes: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1756394
Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>

diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c
index 992bd44a03458ea7fb9d0264e1c566b6a2fb116c..456cfce5e84db72ed808e2e2520c0d1db8799a11 100644 (file)
--- a/src/security/virt-aa-helper.c
+++ b/src/security/virt-aa-helper.c
@@ -777,7 +777,7 @@ vah_add_path(virBufferPtr buf, const char *path, const char *perms, bool recursi
      * 3. re-combine the realpath with the remaining suffix
      * Note: A totally non existent path is used as-is
      */
-     if ((pathdir = mdir_name(path)) == NULL)
+     if (VIR_STRDUP_QUIET(pathdir, path) < 0)
          goto cleanup;
      while (!virFileExists(pathdir)) {
          if ((pathtmp = mdir_name(pathdir)) == NULL)