Bug 203938
| Summary: | makefs: Coverity CID 975345, 975346: No provisions for i/o error | ||
|---|---|---|---|
| Product: | Base System | Reporter: | scdbackup |
| Component: | bin | Assignee: | freebsd-bugs (Nobody) <bugs> |
| Status: | Open --- | ||
| Severity: | Affects Some People | CC: | emaste |
| Priority: | --- | ||
| Version: | CURRENT | ||
| Hardware: | Any | ||
| OS: | Any | ||
| See Also: | https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=203937 | ||
Bulk taking makefs bugs. Releasing bugs back to the pool. |
usr.sbin/makefs/cd9660/cd9660_debug.c CID 975346 (#1 of 2): Ignoring number of bytes read (CHECKED_RETURN) 3. check_return: fread(void * restrict, size_t, size_t, FILE * restrict) returns the number of bytes read, but it is ignored. 208 fread(((unsigned char*)&pttemp) + 8, 1, pttemp.length[0], fd); CID 975345 (#1 of 1): Ignoring number of bytes read (CHECKED_RETURN) 2. check_return: fread(void * restrict, size_t, size_t, FILE * restrict) returns the number of bytes read, but it is ignored. 238 fread(buf, 1, CD9660_SECTOR_SIZE, fd); --------------- Source analysis: Indeed one should check for complete read success. Just above the fread() calls, fseeko() failure leads to err(): 200 if (fseeko(fd, CD9660_SECTOR_SIZE * sector, SEEK_SET) == -1) 201 err(1, "fseeko"); 236 if (fseeko(fd, CD9660_SECTOR_SIZE * sector, SEEK_SET) == -1) 237 err(1, "fseeko"); --------------- Remedy proposal: One should distinguish between EOF and error. - fread(((unsigned char*)&pttemp) + 8, 1, pttemp.length[0], fd); + if (fread(((unsigned char*)&pttemp) + 8, 1, pttemp.length[0], + fd) != pttemp.length[0]) { + if (feof(fd)) + err(1, "EOF on fread"); + err(1, "Error on fread"); + } - fread(buf, 1, CD9660_SECTOR_SIZE, fd); + if (fread(buf, 1, CD9660_SECTOR_SIZE, fd) != + CD9660_SECTOR_SIZE) { + if (feof(fd)) + err(1, "EOF on fread"); + err(1, "Error on fread"); + }