Fuzz: limit input size (#7317)

We know that fuzzParseExpr and fuzzParseMetricSelector make use of heavy
things like regexes, which take a fairly big amount of memory.

OSS-Fuzz does not offer a proper way to increase the memory [1], therefore
we limit the input size [2].

[1] https://google.github.io/oss-fuzz/faq/#how-do-you-handle-timeouts-and-ooms
[2] https://google.github.io/oss-fuzz/getting-started/new-project-guide/#input-size

Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>
This commit is contained in:
Julien Pivotto 2020-05-31 09:42:56 +02:00 committed by GitHub
parent fdc49fae5b
commit 58c445e6ef
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@ -48,6 +48,11 @@ const (
fuzzInteresting = 1
fuzzMeh = 0
fuzzDiscard = -1
// Input size above which we know that Prometheus would consume too much
// memory. The recommended way to deal with it is check input size.
// https://google.github.io/oss-fuzz/getting-started/new-project-guide/#input-size
maxInputSize = 10240
)
func fuzzParseMetricWithContentType(in []byte, contentType string) int {
@ -84,6 +89,9 @@ func FuzzParseOpenMetric(in []byte) int {
// Fuzz the metric selector parser.
func FuzzParseMetricSelector(in []byte) int {
if len(in) > maxInputSize {
return fuzzMeh
}
_, err := parser.ParseMetricSelector(string(in))
if err == nil {
return fuzzInteresting
@ -94,6 +102,9 @@ func FuzzParseMetricSelector(in []byte) int {
// Fuzz the expression parser.
func FuzzParseExpr(in []byte) int {
if len(in) > maxInputSize {
return fuzzMeh
}
_, err := parser.ParseExpr(string(in))
if err == nil {
return fuzzInteresting