Messages in this thread | | | From | "Albert D. Cahalan" <> | Subject | Re: more thoughts on a new jail() system call | Date | Thu, 18 Jul 2002 23:06:06 -0400 (EDT) |
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>> sys_olduname) - P > > I'd argue that this should be restricted, on general > principles. (General principle: A jailed process shouldn't > be able to learn anything about the host it's running on.)
Learning this info is easy enough without a syscall. You only cause trouble for legit usage.
>> sys_getcwd) C >> sys_ustat) J - Do we want a jailed process getting this info? >> sys_statfs) NOT SURE - should a jail process be able to get info on system? >> sys_fstatfs) same as statfs >> sys_sysfs) J - info on local system? > > It's probably not critical, but I'd argue that these should > be denied, on general principles, unless there is some > reason to think it will be very useful. getcwd() is probably > the most critical to deny, as it can give away detailed > information in some cases. > > (General principle: If you're in a jail, you shouldn't be > able to learn any information about where that jail resides > on the filesystem.)
No, sys_getcwd will return info based on your current root. After chroot and all, your "/" is the top of your jail.
>> sys_setsid) NOT SURE - no clue what this really does > > I think it's probably ok, but I'm not 100% sure, either.
Yes it's OK. It's needed for job control.
>> sys_syslog) NOT SURE (probably jailed away) > > sys_syslog touches a global shared resource, hence > should probably be denied to jailed processes.
It's got to be redirected.
>> sys_vhangup) NOT SURE - Should be fine, right? > > Seems ok to me.
Have fun with devpts.
>> sys_getsid) NOT SURE - whats it for? > > You shouldn't be able to call getsid() on some other > process outside the jail. Also, calling getsid() on > yourself might reveal information about your parent, > like getppid() or getpgid() (minor).
Your parent ought to be 1. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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