Messages in this thread | | | Date | Fri, 30 Sep 2011 09:59:41 +0300 | Subject | Re: [PATCH] kernel/groups.c: Minor bugfix for overflow in binary search | From | Pekka Enberg <> |
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On Thu, Sep 29, 2011 at 9:39 PM, Josh Zimmerman <jzimmerm@andrew.cmu.edu> wrote: >> Fixed possible unsigned int overflow bug. (2 + 2^(32) - 1)/2 results in overflow; 2 + (2^(32)-1-2)/2 does not.
On Fri, Sep 30, 2011 at 8:44 AM, Linus Torvalds <torvalds@linux-foundation.org> wrote: > We can't have that many groups anyway, so the overflow is pretty theoretical. > > The max should be NGROUPS_MAX, afaik (65536) and other places have > lower limits (ie sunrpc/nfs). And if some place doesn't limit it > correctly, we have bigger problems than this (the whole allocation and > CPU use issues)
The code site could be converted to lib/bsearch.c::bsearch(), AFAICT. That'd take care of the theoretical overflow too.
Pekka
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