Fuzz btrfsitem, and by consequence improve binstruct errors

15 files changed, 134 insertions, 47 deletions

diff --git a/lib/btrfs/btrfsitem/item_chunk.go b/lib/btrfs/btrfsitem/item_chunk.go
index 7197fb3..2ccc860 100644
--- a/lib/btrfs/btrfsitem/item_chunk.go
+++ b/lib/btrfs/btrfsitem/item_chunk.go
@@ -5,8 +5,6 @@
 package btrfsitem
 
 import (
-	"fmt"
-
 	"git.lukeshu.com/btrfs-progs-ng/lib/binstruct"
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsvol"
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/internal"
@@ -70,7 +68,7 @@ func (chunk *Chunk) UnmarshalBinary(dat []byte) (int, error) {
 		_n, err := binstruct.Unmarshal(dat[n:], &stripe)
 		n += _n
 		if err != nil {
-			return n, fmt.Errorf("%T.UnmarshalBinary: %w", *chunk, err)
+			return n, err
 		}
 		chunk.Stripes = append(chunk.Stripes, stripe)
 	}
@@ -87,7 +85,7 @@ func (chunk Chunk) MarshalBinary() ([]byte, error) {
 		_ret, err := binstruct.Marshal(stripe)
 		ret = append(ret, _ret...)
 		if err != nil {
-			return ret, fmt.Errorf("%T.MarshalBinary: %w", chunk, err)
+			return ret, err
 		}
 	}
 	return ret, nil
diff --git a/lib/btrfs/btrfsitem/item_dir.go b/lib/btrfs/btrfsitem/item_dir.go
index 859cd14..2fb2d41 100644
--- a/lib/btrfs/btrfsitem/item_dir.go
+++ b/lib/btrfs/btrfsitem/item_dir.go
@@ -9,47 +9,21 @@ import (
 	"hash/crc32"
 
 	"git.lukeshu.com/btrfs-progs-ng/lib/binstruct"
+	"git.lukeshu.com/btrfs-progs-ng/lib/binstruct/binutil"
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/internal"
 )
 
-// key.objectid = inode of directory containing this entry
-// key.offset =
-//    for DIR_ITEM and XATTR_ITEM = NameHash(name)
-//    for DIR_INDEX               = index id in the directory (starting at 2, because "." and "..")
-type DirEntries []DirEntry // DIR_ITEM=84 DIR_INDEX=96 XATTR_ITEM=24
+const MaxNameLen = 255
 
 func NameHash(dat []byte) uint64 {
 	return uint64(^crc32.Update(1, crc32.MakeTable(crc32.Castagnoli), dat))
 }
 
-func (o *DirEntries) UnmarshalBinary(dat []byte) (int, error) {
-	*o = nil
-	n := 0
-	for n < len(dat) {
-		var ref DirEntry
-		_n, err := binstruct.Unmarshal(dat, &ref)
-		n += _n
-		if err != nil {
-			return n, err
-		}
-		*o = append(*o, ref)
-	}
-	return n, nil
-}
-
-func (o DirEntries) MarshalBinary() ([]byte, error) {
-	var ret []byte
-	for _, ref := range o {
-		bs, err := binstruct.Marshal(ref)
-		ret = append(ret, bs...)
-		if err != nil {
-			return ret, err
-		}
-	}
-	return ret, nil
-}
-
-type DirEntry struct {
+// key.objectid = inode of directory containing this entry
+// key.offset =
+//    for DIR_ITEM and XATTR_ITEM = NameHash(name)
+//    for DIR_INDEX               = index id in the directory (starting at 2, because "." and "..")
+type DirEntry struct { // DIR_ITEM=84 DIR_INDEX=96 XATTR_ITEM=24
 	Location      internal.Key `bin:"off=0x0, siz=0x11"`
 	TransID       int64        `bin:"off=0x11, siz=8"`
 	DataLen       uint16       `bin:"off=0x19, siz=2"` // [ignored-when-writing]
@@ -61,10 +35,20 @@ type DirEntry struct {
 }
 
 func (o *DirEntry) UnmarshalBinary(dat []byte) (int, error) {
+	if err := binutil.NeedNBytes(dat, 0x1e); err != nil {
+		return 0, err
+	}
 	n, err := binstruct.UnmarshalWithoutInterface(dat, o)
 	if err != nil {
 		return n, err
 	}
+	if o.NameLen > MaxNameLen {
+		return 0, fmt.Errorf("maximum name len is %v, but .NameLen=%v",
+			MaxNameLen, o.NameLen)
+	}
+	if err := binutil.NeedNBytes(dat, 0x1e+int(o.DataLen)+int(o.NameLen)); err != nil {
+		return 0, err
+	}
 	o.Data = dat[n : n+int(o.DataLen)]
 	n += int(o.DataLen)
 	o.Name = dat[n : n+int(o.NameLen)]
diff --git a/lib/btrfs/btrfsitem/item_extent.go b/lib/btrfs/btrfsitem/item_extent.go
index 9257d2b..d49243d 100644
--- a/lib/btrfs/btrfsitem/item_extent.go
+++ b/lib/btrfs/btrfsitem/item_extent.go
@@ -74,8 +74,8 @@ type ExtentHeader struct {
 
 type TreeBlockInfo struct {
 	Key           internal.Key `bin:"off=0, siz=0x11"`
-	Level         uint8        `bin:"off=0x11, siz=0x8"`
-	binstruct.End `bin:"off=0x19"`
+	Level         uint8        `bin:"off=0x11, siz=0x1"`
+	binstruct.End `bin:"off=0x12"`
 }
 
 type ExtentFlags uint64
@@ -131,7 +131,7 @@ func (o *ExtentInlineRef) UnmarshalBinary(dat []byte) (int, error) {
 			return n, err
 		}
 	default:
-		return n, fmt.Errorf("btrfsitem.ExtentInlineRef.UnmarshalBinary: unexpected item type %v", o.Type)
+		return n, fmt.Errorf("unexpected item type %v", o.Type)
 	}
 	return n, nil
 }
@@ -163,7 +163,7 @@ func (o ExtentInlineRef) MarshalBinary() ([]byte, error) {
 			return dat, err
 		}
 	default:
-		return dat, fmt.Errorf("btrfsitem.ExtentInlineRef.MarshalBinary: unexpected item type %v", o.Type)
+		return dat, fmt.Errorf("unexpected item type %v", o.Type)
 	}
 	return dat, nil
 }
diff --git a/lib/btrfs/btrfsitem/item_extentcsum.go b/lib/btrfs/btrfsitem/item_extentcsum.go
index f9c546d..a945295 100644
--- a/lib/btrfs/btrfsitem/item_extentcsum.go
+++ b/lib/btrfs/btrfsitem/item_extentcsum.go
@@ -20,7 +20,7 @@ type ExtentCSum struct { // EXTENT_CSUM=128
 
 func (o *ExtentCSum) UnmarshalBinary(dat []byte) (int, error) {
 	if o.ChecksumSize == 0 {
-		return 0, fmt.Errorf("btrfs.ExtentCSum.UnmarshalBinary: .ChecksumSize must be set")
+		return 0, fmt.Errorf(".ChecksumSize must be set")
 	}
 	for len(dat) >= o.ChecksumSize {
 		var csum btrfssum.CSum
@@ -33,7 +33,7 @@ func (o *ExtentCSum) UnmarshalBinary(dat []byte) (int, error) {
 
 func (o ExtentCSum) MarshalBinary() ([]byte, error) {
 	if o.ChecksumSize == 0 {
-		return nil, fmt.Errorf("btrfs.ExtentCSum.MarshalBinary: .ChecksumSize must be set")
+		return nil, fmt.Errorf(".ChecksumSize must be set")
 	}
 	var dat []byte
 	for _, csum := range o.Sums {
diff --git a/lib/btrfs/btrfsitem/item_inoderef.go b/lib/btrfs/btrfsitem/item_inoderef.go
index e4edf4a..b1eaf1b 100644
--- a/lib/btrfs/btrfsitem/item_inoderef.go
+++ b/lib/btrfs/btrfsitem/item_inoderef.go
@@ -5,7 +5,10 @@
 package btrfsitem
 
 import (
+	"fmt"
+
 	"git.lukeshu.com/btrfs-progs-ng/lib/binstruct"
+	"git.lukeshu.com/btrfs-progs-ng/lib/binstruct/binutil"
 )
 
 // key.objectid = inode number of the file
@@ -18,10 +21,20 @@ type InodeRef struct { // INODE_REF=12
 }
 
 func (o *InodeRef) UnmarshalBinary(dat []byte) (int, error) {
+	if err := binutil.NeedNBytes(dat, 0xA); err != nil {
+		return 0, err
+	}
 	n, err := binstruct.UnmarshalWithoutInterface(dat, o)
 	if err != nil {
 		return n, err
 	}
+	if o.NameLen > MaxNameLen {
+		return 0, fmt.Errorf("maximum name len is %v, but .NameLen=%v",
+			MaxNameLen, o.NameLen)
+	}
+	if err := binutil.NeedNBytes(dat, 0xA+int(o.NameLen)); err != nil {
+		return 0, err
+	}
 	dat = dat[n:]
 	o.Name = dat[:o.NameLen]
 	n += int(o.NameLen)
diff --git a/lib/btrfs/btrfsitem/item_rootref.go b/lib/btrfs/btrfsitem/item_rootref.go
index 228ab55..1ee0ee4 100644
--- a/lib/btrfs/btrfsitem/item_rootref.go
+++ b/lib/btrfs/btrfsitem/item_rootref.go
@@ -5,7 +5,10 @@
 package btrfsitem
 
 import (
+	"fmt"
+
 	"git.lukeshu.com/btrfs-progs-ng/lib/binstruct"
+	"git.lukeshu.com/btrfs-progs-ng/lib/binstruct/binutil"
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/internal"
 )
 
@@ -18,10 +21,20 @@ type RootRef struct { // ROOT_REF=156 ROOT_BACKREF=144
 }
 
 func (o *RootRef) UnmarshalBinary(dat []byte) (int, error) {
+	if err := binutil.NeedNBytes(dat, 0x12); err != nil {
+		return 0, err
+	}
 	n, err := binstruct.UnmarshalWithoutInterface(dat, o)
 	if err != nil {
 		return n, err
 	}
+	if o.NameLen > MaxNameLen {
+		return 0, fmt.Errorf("maximum name len is %v, but .NameLen=%v",
+			MaxNameLen, o.NameLen)
+	}
+	if err := binutil.NeedNBytes(dat, 0x12+int(o.NameLen)); err != nil {
+		return 0, err
+	}
 	o.Name = dat[n : n+int(o.NameLen)]
 	n += int(o.NameLen)
 	return n, nil
diff --git a/lib/btrfs/btrfsitem/items_gen.go b/lib/btrfs/btrfsitem/items_gen.go
index 82743b0..8573967 100644
--- a/lib/btrfs/btrfsitem/items_gen.go
+++ b/lib/btrfs/btrfsitem/items_gen.go
@@ -47,8 +47,8 @@ var keytype2gotype = map[Type]reflect.Type{
 	CHUNK_ITEM_KEY:           reflect.TypeOf(Chunk{}),
 	DEV_EXTENT_KEY:           reflect.TypeOf(DevExtent{}),
 	DEV_ITEM_KEY:             reflect.TypeOf(Dev{}),
-	DIR_INDEX_KEY:            reflect.TypeOf(DirEntries{}),
-	DIR_ITEM_KEY:             reflect.TypeOf(DirEntries{}),
+	DIR_INDEX_KEY:            reflect.TypeOf(DirEntry{}),
+	DIR_ITEM_KEY:             reflect.TypeOf(DirEntry{}),
 	EXTENT_CSUM_KEY:          reflect.TypeOf(ExtentCSum{}),
 	EXTENT_DATA_KEY:          reflect.TypeOf(FileExtent{}),
 	EXTENT_DATA_REF_KEY:      reflect.TypeOf(ExtentDataRef{}),
@@ -70,7 +70,7 @@ var keytype2gotype = map[Type]reflect.Type{
 	TREE_BLOCK_REF_KEY:       reflect.TypeOf(Empty{}),
 	UUID_RECEIVED_SUBVOL_KEY: reflect.TypeOf(UUIDMap{}),
 	UUID_SUBVOL_KEY:          reflect.TypeOf(UUIDMap{}),
-	XATTR_ITEM_KEY:           reflect.TypeOf(DirEntries{}),
+	XATTR_ITEM_KEY:           reflect.TypeOf(DirEntry{}),
 }
 var untypedObjID2gotype = map[internal.ObjID]reflect.Type{
 	internal.FREE_SPACE_OBJECTID: reflect.TypeOf(FreeSpaceHeader{}),
@@ -81,7 +81,7 @@ func (Chunk) isItem()           {}
 func (Dev) isItem()             {}
 func (DevExtent) isItem()       {}
 func (DevStats) isItem()        {}
-func (DirEntries) isItem()      {}
+func (DirEntry) isItem()        {}
 func (Empty) isItem()           {}
 func (Extent) isItem()          {}
 func (ExtentCSum) isItem()      {}
diff --git a/lib/btrfs/btrfsitem/items_test.go b/lib/btrfs/btrfsitem/items_test.go
new file mode 100644
index 0000000..aba8ca2
--- /dev/null
+++ b/lib/btrfs/btrfsitem/items_test.go
@@ -0,0 +1,65 @@
+// Copyright (C) 2022  Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package btrfsitem_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"git.lukeshu.com/btrfs-progs-ng/lib/binstruct"
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsitem"
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfssum"
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/internal"
+)
+
+func FuzzRoundTrip(f *testing.F) {
+	keySize := binstruct.StaticSize(internal.Key{})
+	sumtypeSize := binstruct.StaticSize(btrfssum.CSumType(0))
+
+	f.Add(make([]byte, 256))
+
+	f.Fuzz(func(t *testing.T, inDat []byte) {
+		if len(inDat) < keySize+sumtypeSize {
+			t.Skip()
+		}
+		keyInDat, inDat := inDat[:keySize], inDat[keySize:]
+		sumtypeInDat, inDat := inDat[:sumtypeSize], inDat[sumtypeSize:]
+		itemInDat := inDat
+
+		// key
+
+		var key internal.Key
+		n, err := binstruct.Unmarshal(keyInDat, &key)
+		require.NoError(t, err, "binstruct.Unmarshal(dat, &key)")
+		require.Equal(t, keySize, n, "binstruct.Unmarshal(dat, &key)")
+
+		keyOutDat, err := binstruct.Marshal(key)
+		require.NoError(t, err, "binstruct.Marshal(key)")
+		require.Equal(t, keyInDat, keyOutDat, "binstruct.Marshal(key)")
+
+		// sumtype
+
+		var sumtype btrfssum.CSumType
+		n, err = binstruct.Unmarshal(sumtypeInDat, &sumtype)
+		require.NoError(t, err, "binstruct.Unmarshal(dat, &sumtype)")
+		require.Equal(t, sumtypeSize, n, "binstruct.Unmarshal(dat, &sumtype)")
+
+		sumtypeOutDat, err := binstruct.Marshal(sumtype)
+		require.NoError(t, err, "binstruct.Marshal(sumtype)")
+		require.Equal(t, sumtypeInDat, sumtypeOutDat, "binstruct.Marshal(sumtype)")
+
+		// item
+
+		t.Logf("key=%v sumtype=%v dat=%q", key, sumtype, itemInDat)
+
+		item := btrfsitem.UnmarshalItem(key, sumtype, itemInDat)
+		require.NotNil(t, item, "btrfsitem.UnmarshalItem")
+
+		itemOutDat, err := binstruct.Marshal(item)
+		require.NoError(t, err, "binstruct.Marshal(item)")
+		require.Equal(t, string(itemInDat), string(itemOutDat), "binstruct.Marshal(item)")
+	})
+}
diff --git a/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/12de190a2cae6f0c72854a75c03ce8488d9d0508a66fa4de0817264e458d2260 b/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/12de190a2cae6f0c72854a75c03ce8488d9d0508a66fa4de0817264e458d2260
new file mode 100644
index 0000000..6fb6f2c
--- /dev/null
+++ b/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/12de190a2cae6f0c72854a75c03ce8488d9d0508a66fa4de0817264e458d2260
@@ -0,0 +1,2 @@
+go test fuzz v1
+[]byte("00000000\x9c0000000000000000000000000000")
diff --git a/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/1ecbbb90e92add091b31e3c765955d76d06074ea5dca8f6b4ce523a640d50a2d b/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/1ecbbb90e92add091b31e3c765955d76d06074ea5dca8f6b4ce523a640d50a2d
new file mode 100644
index 0000000..5aa6619
--- /dev/null
+++ b/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/1ecbbb90e92add091b31e3c765955d76d06074ea5dca8f6b4ce523a640d50a2d
@@ -0,0 +1,2 @@
+go test fuzz v1
+[]byte("00000000\x180000000000")
diff --git a/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/2ae21a60c209d36ee27afa2b253c5f0ae7389c05837daa91500317cec5122f2e b/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/2ae21a60c209d36ee27afa2b253c5f0ae7389c05837daa91500317cec5122f2e
new file mode 100644
index 0000000..68454dd
--- /dev/null
+++ b/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/2ae21a60c209d36ee27afa2b253c5f0ae7389c05837daa91500317cec5122f2e
@@ -0,0 +1,2 @@
+go test fuzz v1
+[]byte("00000000\x800000000000")
diff --git a/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/7b05bfc61add24e74c86043bfd0dea657fa522bd2b161d6334effe624c847850 b/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/7b05bfc61add24e74c86043bfd0dea657fa522bd2b161d6334effe624c847850
new file mode 100644
index 0000000..2576860
--- /dev/null
+++ b/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/7b05bfc61add24e74c86043bfd0dea657fa522bd2b161d6334effe624c847850
@@ -0,0 +1,2 @@
+go test fuzz v1
+[]byte("00000000`00000000000000000000000000000000000\x00\x00\x00\x0000")
diff --git a/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/990f7eb92226efeef4491768fae2b9260529446c07a34b99d7e384b5dd847d93 b/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/990f7eb92226efeef4491768fae2b9260529446c07a34b99d7e384b5dd847d93
new file mode 100644
index 0000000..3f5d16a
--- /dev/null
+++ b/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/990f7eb92226efeef4491768fae2b9260529446c07a34b99d7e384b5dd847d93
@@ -0,0 +1,2 @@
+go test fuzz v1
+[]byte("00000000\xa80000000000000000000000000020000000")
diff --git a/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/aff8a82fa526d6a55b4e13d9320aee5f9413109bbab24e3b2269cdd6abb97fb7 b/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/aff8a82fa526d6a55b4e13d9320aee5f9413109bbab24e3b2269cdd6abb97fb7
new file mode 100644
index 0000000..b9c2ffe
--- /dev/null
+++ b/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/aff8a82fa526d6a55b4e13d9320aee5f9413109bbab24e3b2269cdd6abb97fb7
@@ -0,0 +1,2 @@
+go test fuzz v1
+[]byte("00000000`0000000000000000000000000000000000000000")
diff --git a/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/c9330e1640e459c9f623fc40d643eb42f727ed9b0b744c011a39a40552417cad b/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/c9330e1640e459c9f623fc40d643eb42f727ed9b0b744c011a39a40552417cad
new file mode 100644
index 0000000..c117858
--- /dev/null
+++ b/lib/btrfs/btrfsitem/testdata/fuzz/FuzzRoundTrip/c9330e1640e459c9f623fc40d643eb42f727ed9b0b744c011a39a40552417cad
@@ -0,0 +1,2 @@
+go test fuzz v1
+[]byte("00000000\f00000000000000000000")