build initramfs: uncontrolled LD_LIBRARY_PATH

dracut uses ldd when building an initramfs, but I cannot find where dracut controls LD_LIBRARY_PATH during the build. Thus I do not trust the results of ldd. The string "LD_LIBRARY_PATH" does not appear in the dracut source tree, there is no use of "env -i", dracut is not setuid, etc.

At a minimum, the built initramfs could fail to satisfy some DT_NEEDED entry during boot, leading to a crash. Some soname was satisfied by a library in a non-standard directory on the build-time LD_LIBRARY_PATH, and was copied into that non-standard directory of the initramfs, but is not findable using the boot-time (default standard) path list.

That might be the worst, because all users of the initramfs (namely:
booting only) do control LD_LIBRARY_PATH, so there might be "no possibility" of substituting an actual non-standard library. However, it would be safer to control LD_LIBRARY_PATH while building initramfs, or at least document why not.

good find!

index cf27b23..dfa71a1 100755
@@ -265,6 +265,7 @@ fi
 
 PATH=/sbin:/bin:/usr/sbin:/usr/bin
 export PATH
+unset LD_LIBRARY_PATH
 
 [[ $debug ]] && {
     export PS4='${BASH_SOURCE}@${LINENO}(${FUNCNAME[0]}): ';