DAMemDataTable - TDAField.LoadFromStream cuts the blob value

Data Abstract
1

daSample.zip (52.3 KB)

Hello,
I have discovered a serious bug in the TDABlobStream implementation. If I try to write a blob binary value of a specific length, the value is cut (by one to five bytes) and the blob memory buffer is overrun. I have detected it on blob values containing Bin2Streamer’s data, causing the streamer to seriously malfunction (missing read size check).

I have prepared a small sample project to demonstrate the issue. The project just inserts one random value of the offending size. Later it checks for the insterted size. The overrun is not detected in most occasions.

Regard from Prague,
Jaroslav

2

Thanks, logged as bugs://80161

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pls update uDAMemDataset.pas: replace this line in two TDABlobStream.Write methods:

else if Temp.size + SizeOf(TBLOBRecord) < Cardinal(FPosition + Count) then begin

with

else if Temp.size < Cardinal(FPosition + Count) then begin
4

bugs://80161 got closed with status fixed.