Messages in this thread | | | Date | Wed, 14 Oct 1998 06:49:02 -0500 | From | Mitchell Blank Jr <> | Subject | Re: 2.2 imminent.. /proc security fix? |
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Chris Wedgwood wrote: > > The fix stops someone holding open "/proc/<pid>/*" files, letting > > the process exit, then waiting for "pid" to be re-used, gaining > > read access to semi-sensitive info. > > My preferred fix to this, not possible in 2.2.x time is to make uid_t > 32-bit (although this only buys us time... no doubt DaveM or someone > will have a sparc-something that can wrap that is a couple of years).
A 32-bit uid_t would be great for lots of reasons... it's not unthinkable that in the near future people will want to be able to run 80,000 processes on their large servers. I believe Solaris 2.7 is supposed to include this.
As for the /proc/PID/* problem is to just check permissions on each read (I believe this is also done in the lastest 2.0's). The long term solution would be to have a 64 bit process number that is used internally in procfs. We shouldn't try to just garauntee that the PID itself won't be reused - it gets hairy if in the future we want to move to random PIDs (like OpenBSD) or some other scheme.
-Mitch
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