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fix buffer size check #44
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ghost
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Stebalien
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Apr 28, 2019
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Great catch! This is almost certainly the issue. On line 181, we reslice using fullLen. This works because it's still <= the capacity. However, it means that we read more than was asked into this resliced buffer and return the actual size read (which is greater than the size of the original buffer).
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Trying to trace the source of the bug in libp2p/go-mplex#43, I run across this erroneous check.
I don't think that's the source of the bug, but it's still a bug as it can overwrite the buffer past the slice boundary designated by the caller and perform an oversize read.
It also has similar characteristics to what we observe (an oversize read) so there is a (slim) hope that it will fix the issue.