Messages in this thread | | | Date | Wed, 1 Jun 2005 22:39:33 +0200 | From | Willy Tarreau <> | Subject | Re: Suggestion on "int len" sanity |
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On Wed, Jun 01, 2005 at 09:06:33AM +0200, XIAO Gang wrote: > > I would like to make a security suggestion. > > There are many length variables in the kernel, locally declared as "len" > or "length", either as "int", "unsigned int" or "size_t". However, > declaring a length as "int" leads easily to an erroneous situation, as > the author (or even a code checker) might make the implicite hypothesis > that the length is positive, so that it is enough to make a sanity check > of the kind > > if (length > limit) ERROR; > > which is not enough. > > On the other hand, when a variable is named "len" or "length", it is > usually used for length and never should go negative. So could I suggest > that the declarations of these variables to be uniformized to "size_t", > via a gradual but sysmatic cleanup?
Probably true for most cases, but be careful of code which would use -1 to report some errors if such thing exists.
Willy
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