[gdal-dev] Grib2 Question

[Even Rouault]

On mardi 7 novembre 2017 13:51:30 CET Kurt Schwehr wrote:
> It's possible to cause massive allocations with a tiny corrupted grib file
> causing an out-of-memory.  I found that case with the llvm ASAN fuzzer.  If
> you have a specification that gives a more reasoned maximum or a better
> overall check, I'm listening.  I definitely think the sanity checking can
> be improved.  Mostly I just try to survive the g2clib code.  It doesn't
> come with tests and digging through GRIB specs to match up to g2clib source
> isn't my favorite thing to do.
> 
> https://github.com/OSGeo/gdal/commit/ae92f7fb8e32381124a37588d27b9af695afce2
> 0

I guess that if Roarke is asking the question he might have a dataset that breaks this limit ? If 
so, we might consider reverting that change, or making it more robust (which can be very 
tricky I know. Perhaps some heuristics with the file size ?), or just using it in fuzzing mode and 
not in production for now. And a pointer to such a dataset would be much appreciated.

(By the way: 2<<24 is IMHO an usual way of writing a limit. I confused it with 2^24 initially. So 
1 << 25 would perhaps be better. Or just in decimal form as it is completely arbitary and not 
related to a binary encoding)

Even

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