diff options
Diffstat (limited to 'vendor/gopkg.in/yaml.v2/decode.go')
| -rw-r--r-- | vendor/gopkg.in/yaml.v2/decode.go | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/vendor/gopkg.in/yaml.v2/decode.go b/vendor/gopkg.in/yaml.v2/decode.go index 91679b5b4..531087655 100644 --- a/vendor/gopkg.in/yaml.v2/decode.go +++ b/vendor/gopkg.in/yaml.v2/decode.go @@ -318,12 +318,37 @@ func (d *decoder) prepare(n *node, out reflect.Value) (newout reflect.Value, unm return out, false, false } +const ( + // 400,000 decode operations is ~500kb of dense object declarations, or ~5kb of dense object declarations with 10000% alias expansion + alias_ratio_range_low = 400000 + // 4,000,000 decode operations is ~5MB of dense object declarations, or ~4.5MB of dense object declarations with 10% alias expansion + alias_ratio_range_high = 4000000 + // alias_ratio_range is the range over which we scale allowed alias ratios + alias_ratio_range = float64(alias_ratio_range_high - alias_ratio_range_low) +) + +func allowedAliasRatio(decodeCount int) float64 { + switch { + case decodeCount <= alias_ratio_range_low: + // allow 99% to come from alias expansion for small-to-medium documents + return 0.99 + case decodeCount >= alias_ratio_range_high: + // allow 10% to come from alias expansion for very large documents + return 0.10 + default: + // scale smoothly from 99% down to 10% over the range. + // this maps to 396,000 - 400,000 allowed alias-driven decodes over the range. + // 400,000 decode operations is ~100MB of allocations in worst-case scenarios (single-item maps). + return 0.99 - 0.89*(float64(decodeCount-alias_ratio_range_low)/alias_ratio_range) + } +} + func (d *decoder) unmarshal(n *node, out reflect.Value) (good bool) { d.decodeCount++ if d.aliasDepth > 0 { d.aliasCount++ } - if d.aliasCount > 100 && d.decodeCount > 1000 && float64(d.aliasCount)/float64(d.decodeCount) > 0.99 { + if d.aliasCount > 100 && d.decodeCount > 1000 && float64(d.aliasCount)/float64(d.decodeCount) > allowedAliasRatio(d.decodeCount) { failf("document contains excessive aliasing") } switch n.kind { |