On 02/27/2014 03:48 PM, Ken Werner wrote: > Hi, > > I noticed when using chroot's --userspec option the Gnulib's parse_user_spec > function gets called that leads the glibc to dlopen libnss_compat.so.2 > (probably getpwnam() that triggers the libc's NSS mechanism). Since > parse_user_spec is called after the chroot system call the new root directory > will be searched. I guess this means that the chroot utility attempts to > parse the user spec in the "guest" environment. Is this behavior intended? In > my case the chroot environment contains a libnss_compat.so.2 that's not > compatible and the chroot utility fails with: > > /usr/bin/chroot: relocation error: /lib/libnss_compat.so.2: symbol > _nss_files_parse_pwent, version GLIBC_2.0 not defined in file libc.so.6 with > link time reference > > As soon as I LD_PRELOAD libnss_compat.so.2 the "host" environment is used to > parse the user spec. If this is the intended behavior it would be better if > chroot calls the parse_user_spec prior issuing the chroot syscall. Any > thoughts? :)
This issue was noted previously with an explicit workaround: http://lists.gnu.org/archive/html/coreutils/2011-07/msg00057.html Then again with an implicit workaround: http://lists.gnu.org/archive/html/coreutils/2012-05/msg00018.html I had mentioned an amendment to that but there was no response. I'll look at a fix now to do: t_ids = parse_user_spec(); //outside chroot ids = parse_user_spec(); //inside chroot if (!ids) ids = t_ids; thanks, Pádraig.
