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libchdr_chd: Fix potential unsigned multiplication overflow bugs #167

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Merged
rtissera merged 1 commit into from
Jul 19, 2026
Merged

libchdr_chd: Fix potential unsigned multiplication overflow bugs #167

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8 changes: 4 additions & 4 deletions src/libchdr_chd.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2005,14 +2005,14 @@ static chd_error hunk_read_into_memory(chd_file *chd, uint32_t hunknum, uint8_t
free(buf);
return err;
}
memcpy(dest, buf + unit_in_hunk * chd->header.unitbytes, (units_in_hunk - unit_in_hunk) * chd->header.unitbytes);
memcpy(dest, buf + (size_t)unit_in_hunk * chd->header.unitbytes, (size_t)(units_in_hunk - unit_in_hunk) * chd->header.unitbytes);
/* Read second half of hunk which contains blockoffs */
err = hunk_read_into_memory(chd->parent, (blockoffs / units_in_hunk) + 1, buf);
if (err != CHDERR_NONE) {
free(buf);
return err;
}
memcpy(dest + (units_in_hunk - unit_in_hunk) * chd->header.unitbytes, buf, unit_in_hunk * chd->header.unitbytes);
memcpy(dest + (size_t)(units_in_hunk - unit_in_hunk) * chd->header.unitbytes, buf, (size_t)unit_in_hunk * chd->header.unitbytes);
free(buf);
}
break;
Expand Down Expand Up @@ -2057,9 +2057,9 @@ static chd_error map_read(chd_file *chd)
entries = MAP_STACK_ENTRIES;

/* read that many */
if (!seek_and_read(chd, fileoffset, raw_map_entries, entries * entrysize))
if (!seek_and_read(chd, fileoffset, raw_map_entries, entries * (size_t)entrysize))
EARLY_EXIT(err = CHDERR_READ_ERROR);
fileoffset += entries * entrysize;
fileoffset += entries * (size_t)entrysize;

/* process that many */
if (entrysize == MAP_ENTRY_SIZE)
Expand Down