Messages in this thread | | | Date | 19 Dec 2007 20:33:55 -0500 | From | linux@horizon ... | Subject | Re: RFC: permit link(2) to work across --bind mounts ? |
| |
> Why does link(2) not support hard-linking across bind mount points > of the same underlying filesystem ?
Whenever we get mount -r --bind working properly (which I use to place copies of necessary shared libraries inside chroot jails while allowing page cache sharing), this feature would break security.
mkdir /usr/lib/libs.jail for i in $LIST_OF_LIBRARIES; do ln /usr/lib/$i /usr/lib/libs.jail/$i done mount -r /usr/lib/libs.jail /jail/lib chown prisoner /usr/log/jail mount /usr/log/jail /jail/usr/log chrootuid /jail prisoner /bin/untrusted &
Although protections should be enough, but I'd rather avoid having the prisoner link /jail/lib/libfoo.so (write returns EROFS) to /jail/usr/log where it's potentially writeable.
| |