Bound PKG entry table allocation

PKG file_count was used for vector allocation before validating
that the encrypted package data contained the entry table. Limit the
count and require the entry table to fit in the declared data region
before allocating.

Author: acts-1631

rpcs3/Crypto/unpkg.cpp

@@ -121,9 +121,9 @@ bool package_reader::read_header()
 		return false;
 	}
 
-	if (u64{umax} / sizeof(PKGEntry) < u64(m_header.file_count))
+	if (m_header.file_count > PKG_MAX_FILE_COUNT || u64(m_header.file_count) > u64(m_header.data_size) / sizeof(PKGEntry))
 	{
-		pkg_log.error("PKG file count is too large! (0x%x)", m_header.file_count);
+		pkg_log.error("PKG file count is invalid! (count=0x%x, data_size=0x%llx)", m_header.file_count, m_header.data_size);
 		return false;
 	}
 

rpcs3/Crypto/unpkg.h

@@ -14,6 +14,7 @@ enum : u32
 {
 	PKG_HEADER_SIZE  = 0xC0, // sizeof(pkg_header) + sizeof(pkg_unk_checksum)
 	PKG_HEADER_SIZE2 = 0x280,
+	PKG_MAX_FILE_COUNT = 1'000'000,
 	PKG_MAX_FILENAME_SIZE = 256,
 };