[CASSANDRA-15373] validate value sizes in LegacyLayout

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 3.0.20, 3.11.6, 4.0-alpha3, 4.0
• Component/s: Legacy/Local Write-Read Paths
• Bug Category: Correctness - Unrecoverable Corruption / Loss
• Severity: Normal
• Complexity: Normal
• Discovered By: User Report
• Platform: All
• Since Version: 3.0.0

Source Control Link

https://github.com/apache/cassandra/commit/53f604dc1789a800dbcbc3c8aee77f8f36b8b5db

Test and Documentation Plan

circleci

• Assignee: Blake Eggleston Assign to me
• Reporter: Blake Eggleston

Authors

Blake Eggleston

Reviewers

Benedict Elliott Smith, Sam Tunnicliffe

• Created: 23/Oct/19 22:38
• Updated: 15/May/20 08:38
• Resolved: 06/Nov/19 20:14

Description

In 2.1, all values are serialized as variable length blobs, with a length prefix, followed by the actual value, even with fixed width types like int32. The 3.0 storage engine, on the other hand, omits the length prefix for fixed width types. Since the length of fixed width types are not validated on the 3.0 write path, writing data for a fixed width type from an incorrectly sized byte buffer will over or underflow the space allocated for it, corrupting the remainder of that partition or indexed region from being read. This is not discovered until we attempt to read the corrupted value. This patch updates LegacyLayout to throw a marshal exception if it encounters an unexpected value size for fixed size columns.

Issue Links

• relates to: CASSANDRA-15778 CorruptSSTableException after a 2.1 SSTable is upgraded to 3.0, failing reads