diff options
| -rw-r--r-- | src/crypto/subtle/xor_generic.go | 8 | ||||
| -rw-r--r-- | test/fixedbugs/issue59334.go | 18 |
2 files changed, 25 insertions, 1 deletions
diff --git a/src/crypto/subtle/xor_generic.go b/src/crypto/subtle/xor_generic.go index 482fcf9b4b..7dc89e315b 100644 --- a/src/crypto/subtle/xor_generic.go +++ b/src/crypto/subtle/xor_generic.go @@ -46,7 +46,13 @@ func aligned(dst, x, y *byte) bool { // words returns a []uintptr pointing at the same data as x, // with any trailing partial word removed. func words(x []byte) []uintptr { - return unsafe.Slice((*uintptr)(unsafe.Pointer(&x[0])), uintptr(len(x))/wordSize) + n := uintptr(len(x)) / wordSize + if n == 0 { + // Avoid creating a *uintptr that refers to data smaller than a uintptr; + // see issue 59334. + return nil + } + return unsafe.Slice((*uintptr)(unsafe.Pointer(&x[0])), n) } func xorLoop[T byte | uintptr](dst, x, y []T) { diff --git a/test/fixedbugs/issue59334.go b/test/fixedbugs/issue59334.go new file mode 100644 index 0000000000..06c12cf92f --- /dev/null +++ b/test/fixedbugs/issue59334.go @@ -0,0 +1,18 @@ +// run -tags=purego -gcflags=all=-d=checkptr + +// Copyright 2023 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package main + +import "crypto/subtle" + +func main() { + dst := make([]byte, 5) + src := make([]byte, 5) + for _, n := range []int{1024, 2048} { // just to make the size non-constant + b := make([]byte, n) + subtle.XORBytes(dst, src, b[n-5:]) + } +} |