time: Integer overflow in Date · golang/go#56909

2022-11-22T17:29:36.000Z

### What version of Go are you using (`go version`)? $ go version go version go1.19.3 linux/amd64 ### Does this issue reproduce with the latest release? Yes ### What operating system and processor architecture are you using (`go env`)? go env Output $ go env GO111MODULE="" GOARCH="amd64" GOBIN="" GOCACHE="/home/sylvain/.cache/go-build" GOENV="/home/sylvain/.config/go/env" GOEXE="" GOEXPERIMENT="" GOFLAGS="" GOHOSTARCH="amd64" GOHOSTOS="linux" GOINSECURE="" GOMODCACHE="/home/sylvain/go/pkg/mod" GONOPROXY="" GONOSUMDB="" GOOS="linux" GOPATH="/home/sylvain/go" GOPRIVATE="" GOPROXY="https://proxy.golang.org,direct" GOROOT="/usr/lib/go" GOSUMDB="sum.golang.org" GOTMPDIR="" GOTOOLDIR="/usr/lib/go/pkg/tool/linux_amd64" GOVCS="" GOVERSION="go1.19.3" GCCGO="gccgo" GOAMD64="v1" AR="ar" CC="gcc" CXX="g++" CGO_ENABLED="1" GOMOD="/dev/null" GOWORK="" CGO_CFLAGS="-g -O2" CGO_CPPFLAGS="" CGO_CXXFLAGS="-g -O2" CGO_FFLAGS="-g -O2" CGO_LDFLAGS="-g -O2" PKG_CONFIG="pkg-config" GOGCCFLAGS="-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build3696417096=/tmp/go-build -gno-record-gcc-switches" ### What did you do? The function `Date` of package `time` has an integer overflow. The year number is used to compute the number of days since epoch and then multiply be the number of second in a day: https://cs.opensource.google/go/go/+/refs/tags/go1.19.3:src/time/time.go;l=1496;drc=4b43b741710eb87cbae25f19cbde7eb733b08df1 without check. If the year number is above 549755813887 it overflows the number of second and the year number is negative. Proof of concept: https://go.dev/play/p/9dteWLSkjdn It seems to be related to the issue #20678 but the integer overflow is reached with values on 39 bits only. It allows to have date far in the future seeing in the past. ### What did you expect to see? A positive date and `true` as output or an error. ### What did you see instead? ```bash -34798235367-01-21 16:59:44 +0000 UTC false ```

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Description

What version of Go are you using (`go version`)?

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (`go env`)?

What did you do?

The function Date of package time has an integer overflow. The year number is used to compute the number of days since epoch and then multiply be the number of second in a day: https://cs.opensource.google/go/go/+/refs/tags/go1.19.3:src/time/time.go;l=1496;drc=4b43b741710eb87cbae25f19cbde7eb733b08df1 without check. If the year number is above 549755813887 it overflows the number of second and the year number is negative.

Proof of concept: https://go.dev/play/p/9dteWLSkjdn

It seems to be related to the issue #20678 but the integer overflow is reached with values on 39 bits only. It allows to have date far in the future seeing in the past.

What did you expect to see?

A positive date and true as output or an error.

What did you see instead?

-34798235367-01-21 16:59:44 +0000 UTC
false

Contributor guide

Research direction: Inspect the time.Date function and fix the integer overflow caused by large year values in second calculation.
Tech stack: go
Domain: backend
Issue type: Bug
Difficulty: 2
Estimated time: 1-3 hours
Activity status: Active
Clarity: Clear
Prerequisites: Go
Newbie friendliness: 65