fix: avoid SIGBUS when reading non-std series segment files (#24509) (#24520)

cmd/influxd/inspect/verify_seriesfile/verify_seriesfile.go

@@ -269,7 +269,7 @@ func (v verify) verifySegment(segmentPath string, ids map[uint64]IDData) (valid
 	v.Logger = v.Logger.With(zap.String("segment", segmentName))
 	v.Logger.Info("Verifying segment")
 
-	// Open up the segment and grab it's data.
+	// Open up the segment and grab its data.
 	segmentID, err := tsdb.ParseSeriesSegmentFilename(segmentName)
 	if err != nil {
 		return false, err
@@ -280,7 +280,8 @@ func (v verify) verifySegment(segmentPath string, ids map[uint64]IDData) (valid
 		return false, nil
 	}
 	defer segment.Close()
-	buf := newBuffer(segment.Data())
+	// Only walk the file as it exists, not the whole mapping which may be bigger than the file.
+	buf := newBuffer(segment.Data()[:segment.Size()])
 
 	defer func() {
 		if rec := recover(); rec != nil {

tsdb/series_file.go

@@ -366,9 +366,9 @@ func AppendSeriesKey(dst []byte, name []byte, tags models.Tags) []byte {
 }
 
 // ReadSeriesKey returns the series key from the beginning of the buffer.
-func ReadSeriesKey(data []byte) (key, remainder []byte) {
+func ReadSeriesKey(data []byte) (key []byte) {
 	sz, n := binary.Uvarint(data)
-	return data[:int(sz)+n], data[int(sz)+n:]
+	return data[:int(sz)+n]
 }
 
 func ReadSeriesKeyLen(data []byte) (sz int, remainder []byte) {

tsdb/series_partition.go

@@ -507,7 +507,7 @@ func (p *SeriesPartition) seriesKeyByOffset(offset int64) []byte {
 			continue
 		}
 
-		key, _ := ReadSeriesKey(segment.Slice(pos + SeriesEntryHeaderSize))
+		key := ReadSeriesKey(segment.Slice(pos + SeriesEntryHeaderSize))
 		return key
 	}
 

tsdb/series_segment.go

@@ -92,6 +92,12 @@ func CreateSeriesSegment(id uint16, path string) (*SeriesSegment, error) {
 // Open memory maps the data file at the file's path.
 func (s *SeriesSegment) Open() error {
 	if err := func() (err error) {
+		st, err := os.Stat(s.path)
+		if err != nil {
+			return fmt.Errorf("cannot stat %s: %w", s.path, err)
+		}
+		s.size = uint32(st.Size())
+
 		// Memory map file data.
 		if s.data, err = mmap.Map(s.path, int64(SeriesSegmentSize(s.id))); err != nil {
 			return err
@@ -120,14 +126,16 @@ func (s *SeriesSegment) Path() string { return s.path }
 // InitForWrite initializes a write handle for the segment.
 // This is only used for the last segment in the series file.
 func (s *SeriesSegment) InitForWrite() (err error) {
-	// Only calculate segment data size if writing.
-	for s.size = uint32(SeriesSegmentHeaderSize); s.size < uint32(len(s.data)); {
-		flag, _, _, sz := ReadSeriesEntry(s.data[s.size:])
+	// Only recalculate segment data size if writing.
+	var size uint32
+	for size = uint32(SeriesSegmentHeaderSize); size < s.size; {
+		flag, _, _, sz := ReadSeriesEntry(s.data[size:s.size])
 		if !IsValidSeriesEntryFlag(flag) {
 			break
 		}
-		s.size += uint32(sz)
+		size += uint32(sz)
 	}
+	s.size = size
 
 	// Open file handler for writing & seek to end of data.
 	if s.file, err = os.OpenFile(s.path, os.O_WRONLY|os.O_CREATE, 0666); err != nil {
@@ -243,8 +251,8 @@ func (s *SeriesSegment) MaxSeriesID() uint64 {
 
 // ForEachEntry executes fn for every entry in the segment.
 func (s *SeriesSegment) ForEachEntry(fn func(flag uint8, id uint64, offset int64, key []byte) error) error {
-	for pos := uint32(SeriesSegmentHeaderSize); pos < uint32(len(s.data)); {
-		flag, id, key, sz := ReadSeriesEntry(s.data[pos:])
+	for pos := uint32(SeriesSegmentHeaderSize); pos < s.size; {
+		flag, id, key, sz := ReadSeriesEntry(s.data[pos:s.size])
 		if !IsValidSeriesEntryFlag(flag) {
 			break
 		}
@@ -337,7 +345,7 @@ func ReadSeriesKeyFromSegments(a []*SeriesSegment, offset int64) []byte {
 		return nil
 	}
 	buf := segment.Slice(pos)
-	key, _ := ReadSeriesKey(buf)
+	key := ReadSeriesKey(buf)
 	return key
 }
 
@@ -416,16 +424,22 @@ func (hdr *SeriesSegmentHeader) WriteTo(w io.Writer) (n int64, err error) {
 }
 
 func ReadSeriesEntry(data []byte) (flag uint8, id uint64, key []byte, sz int64) {
+	if len(data) <= 0 {
+		return 0, 0, nil, 1
+	}
 	// If flag byte is zero then no more entries exist.
 	flag, data = uint8(data[0]), data[1:]
 	if !IsValidSeriesEntryFlag(flag) {
 		return 0, 0, nil, 1
 	}
 
+	if len(data) < 8 {
+		return 0, 0, nil, 1
+	}
 	id, data = binary.BigEndian.Uint64(data), data[8:]
 	switch flag {
 	case SeriesEntryInsertFlag:
-		key, _ = ReadSeriesKey(data)
+		key = ReadSeriesKey(data)
 	}
 	return flag, id, key, int64(SeriesEntryHeaderSize + len(key))
 }

tsdb/series_segment_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"os"
 	"path/filepath"
+	"strconv"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
@@ -139,44 +140,59 @@ func TestSeriesSegmentHeader(t *testing.T) {
 }
 
 func TestSeriesSegment_PartialWrite(t *testing.T) {
-	dir := t.TempDir()
+	for extraSegs := uint64(2000); extraSegs < 4000; extraSegs++ {
+		func() {
+			dir, cleanup := MustTempDir()
+			defer cleanup()
 
-	// Create a new initial segment (4mb) and initialize for writing.
-	segment, err := tsdb.CreateSeriesSegment(0, filepath.Join(dir, "0000"))
-	if err != nil {
-		t.Fatal(err)
-	} else if err := segment.InitForWrite(); err != nil {
-		t.Fatal(err)
-	}
-	defer segment.Close()
+			// Create a new initial segment (4mb) and initialize for writing.
+			segment, err := tsdb.CreateSeriesSegment(0, filepath.Join(dir, "0000"))
+			if err != nil {
+				t.Fatal(err)
+			} else if err := segment.InitForWrite(); err != nil {
+				t.Fatal(err)
+			}
+			defer segment.Close()
 
-	// Write two entries.
-	if _, err := segment.WriteLogEntry(tsdb.AppendSeriesEntry(nil, tsdb.SeriesEntryInsertFlag, 1, tsdb.AppendSeriesKey(nil, []byte("A"), nil))); err != nil {
-		t.Fatal(err)
-	} else if _, err := segment.WriteLogEntry(tsdb.AppendSeriesEntry(nil, tsdb.SeriesEntryInsertFlag, 2, tsdb.AppendSeriesKey(nil, []byte("B"), nil))); err != nil {
-		t.Fatal(err)
-	}
-	sz := segment.Size()
-	entrySize := len(tsdb.AppendSeriesEntry(nil, tsdb.SeriesEntryInsertFlag, 2, tsdb.AppendSeriesKey(nil, []byte("B"), nil)))
+			// Write two entries.
+			if _, err := segment.WriteLogEntry(tsdb.AppendSeriesEntry(nil, tsdb.SeriesEntryInsertFlag, 1, tsdb.AppendSeriesKey(nil, []byte("A"), nil))); err != nil {
+				t.Fatal(err)
+			}
 
-	// Close segment.
-	if err := segment.Close(); err != nil {
-		t.Fatal(err)
-	}
+			// Adding intermediary segments in between "A" and "B" is to try and induce a SIGBUS
+			// when the file truncation backs over a page.
+			for i := uint64(0); i < extraSegs; i++ {
+				if _, err := segment.WriteLogEntry(tsdb.AppendSeriesEntry(nil, tsdb.SeriesEntryInsertFlag, 1+i, tsdb.AppendSeriesKey(nil, []byte(strconv.Itoa(int(i))), nil))); err != nil {
+					t.Fatal(err)
+				}
+			}
 
-	// Truncate at each point and reopen.
-	for i := entrySize; i > 0; i-- {
-		if err := os.Truncate(filepath.Join(dir, "0000"), sz-int64(entrySize-i)); err != nil {
-			t.Fatal(err)
-		}
-		segment := tsdb.NewSeriesSegment(0, filepath.Join(dir, "0000"))
-		if err := segment.Open(); err != nil {
-			t.Fatal(err)
-		} else if err := segment.InitForWrite(); err != nil {
-			t.Fatal(err)
-		} else if err := segment.Close(); err != nil {
-			t.Fatal(err)
-		}
+			if _, err := segment.WriteLogEntry(tsdb.AppendSeriesEntry(nil, tsdb.SeriesEntryInsertFlag, 2+extraSegs, tsdb.AppendSeriesKey(nil, []byte("B"), nil))); err != nil {
+				t.Fatal(err)
+			}
+			sz := segment.Size()
+			entrySize := len(tsdb.AppendSeriesEntry(nil, tsdb.SeriesEntryInsertFlag, 2+extraSegs, tsdb.AppendSeriesKey(nil, []byte("B"), nil)))
+
+			// Close segment.
+			if err := segment.Close(); err != nil {
+				t.Fatal(err)
+			}
+
+			// Truncate at each point and reopen.
+			for i := entrySize; i > 0; i-- {
+				if err := os.Truncate(filepath.Join(dir, "0000"), sz-int64(entrySize-i)); err != nil {
+					t.Fatal(err)
+				}
+				segment := tsdb.NewSeriesSegment(0, filepath.Join(dir, "0000"))
+				if err := segment.Open(); err != nil {
+					t.Fatal(err)
+				} else if err := segment.InitForWrite(); err != nil {
+					t.Fatal(err)
+				} else if err := segment.Close(); err != nil {
+					t.Fatal(err)
+				}
+			}
+		}()
 	}
 }
 

tsdb/shard_test.go

@@ -2456,6 +2456,14 @@ func (sh *Shard) MustWritePointsString(s string) {
 	}
 }
 
+func MustTempDir() (string, func()) {
+	dir, err := os.MkdirTemp("", "shard-test")
+	if err != nil {
+		panic(fmt.Sprintf("failed to create temp dir: %v", err))
+	}
+	return dir, func() { os.RemoveAll(dir) }
+}
+
 type seriesIterator struct {
 	keys [][]byte
 }