diff options
Diffstat (limited to 'src/net/textproto/reader.go')
| -rw-r--r-- | src/net/textproto/reader.go | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/src/net/textproto/reader.go b/src/net/textproto/reader.go index c1284fde25e..1ad4416ee18 100644 --- a/src/net/textproto/reader.go +++ b/src/net/textproto/reader.go @@ -483,12 +483,12 @@ var colon = []byte(":") // "Long-Key": {"Even Longer Value"}, // } func (r *Reader) ReadMIMEHeader() (MIMEHeader, error) { - return readMIMEHeader(r, math.MaxInt64) + return readMIMEHeader(r, math.MaxInt64, math.MaxInt64) } // readMIMEHeader is a version of ReadMIMEHeader which takes a limit on the header size. // It is called by the mime/multipart package. -func readMIMEHeader(r *Reader, lim int64) (MIMEHeader, error) { +func readMIMEHeader(r *Reader, maxMemory, maxHeaders int64) (MIMEHeader, error) { // Avoid lots of small slice allocations later by allocating one // large one ahead of time which we'll cut up into smaller // slices. If this isn't big enough later, we allocate small ones. @@ -506,7 +506,7 @@ func readMIMEHeader(r *Reader, lim int64) (MIMEHeader, error) { // Account for 400 bytes of overhead for the MIMEHeader, plus 200 bytes per entry. // Benchmarking map creation as of go1.20, a one-entry MIMEHeader is 416 bytes and large // MIMEHeaders average about 200 bytes per entry. - lim -= 400 + maxMemory -= 400 const mapEntryOverhead = 200 // The first line cannot start with a leading space. @@ -538,16 +538,21 @@ func readMIMEHeader(r *Reader, lim int64) (MIMEHeader, error) { continue } + maxHeaders-- + if maxHeaders < 0 { + return nil, errors.New("message too large") + } + // Skip initial spaces in value. value := string(bytes.TrimLeft(v, " \t")) vv := m[key] if vv == nil { - lim -= int64(len(key)) - lim -= mapEntryOverhead + maxMemory -= int64(len(key)) + maxMemory -= mapEntryOverhead } - lim -= int64(len(value)) - if lim < 0 { + maxMemory -= int64(len(value)) + if maxMemory < 0 { // TODO: This should be a distinguishable error (ErrMessageTooLarge) // to allow mime/multipart to detect it. return m, errors.New("message too large") |