client/db/bolt: fix data corruption from reused buffers#561
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The returned byte slice from bbolt.(*Bucket).Get is not valid outside of the transaction where it is used. This change fixes several places where the []byte was used without copying it, resulting in corrupted data. Add the client/db/bolt.getCopy function to load a value and make a copy. If the loaded value is an empty slice, it returns nil. Thus, to identify a non-existent value, use Bucket.Get directly instead. getCopy covers most of the cases where we want to get the value in a slice that is safe to use outside of a transaction, and when we do not wish to load an empty non-nil slice when nil was actually stored. Notably, this fixes decodeOrderBucket, and possibly filteredMatches, makeWallet, and NotificationsN.
buck54321
approved these changes
Jul 23, 2020
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The returned byte slice from
bbolt.(*Bucket).Getis not valid outside ofthe transaction where it is used. This change fixes several places
where the
[]bytewas used outside of the transaction without copying it,resulting in mysteriously corrupted data, including
ChangeCoin.Add the
client/db/bolt.getCopyfunction to load a value and make a copy.If the loaded value is an empty slice, it returns nil. Thus, to
identify a non-existent value, use
Bucket.Getdirectly instead.getCopycovers most of the cases where we want to get the value into aslice that is safe to use outside of a transaction, and when we do not
wish to load an empty non-nil slice when nil was actually stored.
Notably, this fixes
decodeOrderBucket,DecodeMatchProof, andmakeWallet>DecodeWallet(keyB).Likely resolves the "
btc coin 0000000000000000000000000000000000000000000000000000000000000000:0 not found" issue reported in #531 (review). I reproduced the issue with a different but equally impossible coin id of00000000000000000000000000000000000000000000002a000000516b444b63:131074after starting dexc with an active match inTakerSwapCastand following that with new matches.