Unchecked errors are especially pernicious in operating system file management code. Transient or permanent hardware failures are inevitable, and error-management bugs at the file system layer can cause silent, unrecoverable data corruption. We propose an interprocedural static analysis that tracks errors as they propagate through file system code. Our implementation detects overwritten, out-ofscope, and unsaved unchecked errors. Analysis of four widely-used Linux file system implementations (CIFS, ext3, IBM JFS and ReiserFS), a relatively new file system implementation (ext4), and shared virtual file system (VFS) code uncovers 312 error propagation bugs. Our flow- and context-sensitive approach produces more precise results than related techniques while providing better diagnostic information, including possible execution paths that demonstrate each bug found. Categories and Subject Descriptors D.2.4 [Software Engineering]: Software/Program Verification—formal methods, reli...
Cindy Rubio-González, Haryadi S. Gunawi, Be