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nil dereference panics prevention #566

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nil dereference panics prevention #566

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af9fc63
Svace static analyzer fix
Aug 21, 2025
dfb3de9
Merge branch 'go-ldap:master' into master
artemseleznev Sep 17, 2025
7235d32
Update control.go
artemseleznev Sep 17, 2025
310ad69
outofrange and nil dereference panics fix
artemseleznev Sep 18, 2025
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21 changes: 21 additions & 0 deletions v3/control.go
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Original file line number Diff line number Diff line change
Expand Up @@ -605,6 +605,9 @@ func DecodeControl(packet *ber.Packet) (Control, error) {
case ControlTypeManageDsaIT:
return NewControlManageDsaIT(Criticality), nil
case ControlTypePaging:
if value == nil {
return nil, fmt.Errorf("nil value for Control Type ControlTypePaging")
}
value.Description += " (Paging)"
c := new(ControlPaging)
if value.Value != nil {
Expand All @@ -625,6 +628,9 @@ func DecodeControl(packet *ber.Packet) (Control, error) {
value.Children[1].Value = c.Cookie
return c, nil
case ControlTypeBeheraPasswordPolicy:
if value == nil {
return nil, fmt.Errorf("nil value for Control Type ControlTypeBeheraPasswordPolicy")
}
value.Description += " (Password Policy - Behera)"
c := NewControlBeheraPasswordPolicy()
if value.Value != nil {
Expand Down Expand Up @@ -700,23 +706,35 @@ func DecodeControl(packet *ber.Packet) (Control, error) {
case ControlTypeServerSideSortingResult:
return NewControlServerSideSortingResult(value)
case ControlTypeDirSync:
if value == nil {
return nil, fmt.Errorf("nil value for Control Type ControlTypeDirSync")
}
value.Description += " (DirSync)"
return NewResponseControlDirSync(value)
case ControlTypeSyncState:
if value == nil {
return nil, fmt.Errorf("nil value for Control Type ControlTypeSyncState")
}
value.Description += " (Sync State)"
valueChildren, err := ber.DecodePacketErr(value.Data.Bytes())
if err != nil {
return nil, fmt.Errorf("failed to decode data bytes: %s", err)
}
return NewControlSyncState(valueChildren)
case ControlTypeSyncDone:
if value == nil {
return nil, fmt.Errorf("nil value for Control Type ControlTypeSyncDone")
}
value.Description += " (Sync Done)"
valueChildren, err := ber.DecodePacketErr(value.Data.Bytes())
if err != nil {
return nil, fmt.Errorf("failed to decode data bytes: %s", err)
}
return NewControlSyncDone(valueChildren)
case ControlTypeSyncInfo:
if value == nil {
return nil, fmt.Errorf("nil value for Control Type ControlTypeSyncInfo")
}
value.Description += " (Sync Info)"
valueChildren, err := ber.DecodePacketErr(value.Data.Bytes())
if err != nil {
Expand Down Expand Up @@ -911,6 +929,9 @@ func (c *ControlServerSideSorting) GetControlType() string {
}

func NewControlServerSideSorting(value *ber.Packet) (*ControlServerSideSorting, error) {
if value == nil || len(value.Children) < 2 {
return new(ControlServerSideSorting), nil
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This would satisfy your scanner, but would result in a faulty message due to the controlValue not having the necesarry fields for encoding the message.

ldap/v3/control.go

Lines 948 to 979 in 82fef14

func (c *ControlServerSideSorting) Encode() *ber.Packet {
packet := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Control")
control := ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, c.GetControlType(), "Control Type")
value := ber.Encode(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, nil, "Control Value")
seqs := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "SortKeyList")
for _, f := range c.SortKeys {
seq := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "")
seq.AppendChild(
ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, f.AttributeType, "attributeType"),
)
seq.AppendChild(
ber.NewString(ber.ClassContext, ber.TypePrimitive, 0, f.MatchingRule, "orderingRule"),
)
if f.Reverse {
seq.AppendChild(
ber.NewBoolean(ber.ClassContext, ber.TypePrimitive, 1, f.Reverse, "reverseOrder"),
)
}
seqs.AppendChild(seq)
}
value.AppendChild(seqs)
packet.AppendChild(control)
packet.AppendChild(value)
return packet
}

I suggest to disregard this particular change. The function is never called from a message processor but only by a developer.

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@artemseleznev artemseleznev Sep 22, 2025 •
edited
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@cpuschma thank you for your feedback!
Yes, I fix this because the scanner marked this code, but I also prefer not to get panics in my project:-)

Please let me know if my fixes are excess, or some of them (not only in NewControlServerSideSorting)

}
sortKeys := []*SortKey{}

val := value.Children[1].Children
Expand Down
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