crypto/internal/fips140/sha256: sporadic panics when calling "(crypto/x509).SystemCertPool()" #76169
Description
Go version
go1.25.3
Output of go env in your module/workspace:
This was observed on a prod system. `go version -m $BINARY_PATH` yields the following:
[BINARY_NAME]: go1.25.3
[.. REDACTED ..]
build -buildmode=exe
build -compiler=gc
build -ldflags="-w -s -X [REDACTED]"
build CGO_ENABLED=0
build GOARCH=arm64
build GOOS=linux
build GOARM64=v8.0
[.. REDACTED ..]What did you do?
We observed the following panic on one of our prod systems:
panic: runtime error: slice bounds out of range [3616445671586817383:64]
goroutine 1 [running]:
runtime/debug.Stack()
/usr/local/go/src/runtime/debug/stack.go:26 +0x5e
main.main.func1()
/go/src/[REDACTED]/main.go:306 +0x39
panic({0x1027e80?, 0xc0003817e8?})
/usr/local/go/src/runtime/panic.go:783 +0x132
crypto/internal/fips140/sha256.(*Digest).Write(0xc0005667f0, {0xc000229500?, 0x33c, 0x870?})
/usr/local/go/src/crypto/internal/fips140/sha256/sha256.go:176 +0x274
crypto/sha256.Sum224({0xc000229500, 0x33c, 0x348})
/usr/local/go/src/crypto/sha256/sha256.go:70 +0xa7
crypto/x509.(*CertPool).AppendCertsFromPEM(0xc0004ec360, {0xc000600000?, 0x0?, 0x10ac6c8?})
/usr/local/go/src/crypto/x509/cert_pool.go:239 +0x179
crypto/x509.loadSystemRoots()
/usr/local/go/src/crypto/x509/root_unix.go:72 +0x3a5
crypto/x509.initSystemRoots()
/usr/local/go/src/crypto/x509/root.go:40 +0x56
sync.(*Once).doSlow(0xc00012c1a8?, 0xc000022b10?)
/usr/local/go/src/sync/once.go:78 +0xac
sync.(*Once).Do(...)
/usr/local/go/src/sync/once.go:69
crypto/x509.systemRootsPool()
/usr/local/go/src/crypto/x509/root.go:31 +0x45
crypto/x509.SystemCertPool()
/usr/local/go/src/crypto/x509/cert_pool.go:118 +0x25
[REDACTED]/pkg/auth.TLSConfigFromFile({0x10ba74e?, 0x11}, {0x0, 0x0})
/go/src/[REDACTED]/pkg/auth/token.go:380 +0x66
main.main()
/go/src/[REDACTED]/main.go:532 +0x386c
Where [REDACTED]/pkg/auth/token.go includes the following:
import (
"crypto/x509"
)
cp, err := x509.SystemCertPool() // Line 380
We did not investigate this yet but the lower bound in slice bounds out of range [3616445671586817383:64] seems very incorrect.
The panic itself occurs here: https://github.com/golang/go/blob/go1.25.3/src/crypto/internal/fips140/sha256/sha256.go#L176
Find attached the system root store in use on that system (/etc/ssl/certs/ca-certificates.crt which was taken from arm64v8/debian:bookworm-slim):
ca-certificates.crt
What did you see happen?
See above.
What did you expect to see?
Panic should not occur.