Enforce that no bytes remain for TransactionU16LenLimited read

dunxen · dunxen · commit 33e901a88f43 · 2023-05-09T08:37:58.000+02:00
diff --git a/lightning/src/util/ser.rs b/lightning/src/util/ser.rs
@@ -1384,7 +1384,12 @@ impl Readable for TransactionU16LenLimited {
 	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 		let len = <u16 as Readable>::read(r)?;
 		let mut tx_reader = FixedLengthReader::new(r, len as u64);
-		Ok(Self(Readable::read(&mut tx_reader)?))
+		let tx: Transaction = Readable::read(&mut tx_reader)?;
+		if tx_reader.bytes_remain() {
+			Err(DecodeError::BadLengthDescriptor)
+		} else {
+			Ok(Self(tx))
+		}
 	}
 }
 

Original file line number	Diff line number	Diff line change
`@@ -1384,7 +1384,12 @@ impl Readable for TransactionU16LenLimited {`
`1384`	`1384`	`fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {`
`1385`	`1385`	`let len = <u16 as Readable>::read(r)?;`
`1386`	`1386`	`let mut tx_reader = FixedLengthReader::new(r, len as u64);`
`1387`		`- Ok(Self(Readable::read(&mut tx_reader)?))`
	`1387`	`+ let tx: Transaction = Readable::read(&mut tx_reader)?;`
	`1388`	`+ if tx_reader.bytes_remain() {`
	`1389`	`+ Err(DecodeError::BadLengthDescriptor)`
	`1390`	`+ } else {`
	`1391`	`+ Ok(Self(tx))`
	`1392`	`+ }`
`1388`	`1393`	`}`
`1389`	`1394`	`}`
`1390`	`1395`