Messages in this thread | | | Date | Mon, 21 Jul 2003 21:31:44 +0200 | From | Ingo Oeser <> | Subject | Re: Suggestion for a new system call: convert file handle to a cookie for transfering file handles between processes.) |
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On Mon, Jul 21, 2003 at 01:27:06PM -0400, Jan Harkes wrote: > - Refcounting issues, a rogue application can quickle use up kernel > resources by requesting thousands of cookies, he isn't even limited by > per-process resource limits, as it is possible to open a file, grab a > cookie, and close the file. The only 'solution' you have is a timeout > on the cookie, possibly this could be extended by some scheme where > cookies are dropped more agressivly. But any such solution will either > not be sufficient to protect the system from resource exhaustion or > provide the opportunity for denial of service attacks.
Best of all: How big you make the number, doesn't matter: You can always guess such numbers as a local attacker. If not now, then in some years (want to recompile all existing applications then?).
cmsg(SCM_RIGHTS) is the much better solution, if you really have processes, which are neither a sibling nor a parent/child relationship.
And it's also ugly enough ;-)
Regards
Ingo Oeser - 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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