3e4810484afix: fix zlib pointer alignment Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com> Co-authored-by: Shelley Vohr <shelley.vohr@gmail.com>
50 lines
2.3 KiB
Diff
50 lines
2.3 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
|
|
From: Jeroen Hofstee <jhofstee@victronenergy.com>
|
|
Date: Tue, 1 Apr 2025 20:09:31 +0000
|
|
Subject: zlib: fix pointer alignment
|
|
|
|
The function AllocForBrotli prefixes the allocated memory with its
|
|
size, and returns a pointer to the region after it. This pointer can
|
|
however no longer be suitably aligned. Correct this by allocating
|
|
the maximum of the the size of the size_t and the max alignment.
|
|
|
|
On Arm 32bits the size_t is 4 bytes long, but the alignment is 8 for
|
|
some NEON instructions. When Brotli is compiled with optimizations
|
|
enabled newer GCC versions will use the NEON instructions and trigger
|
|
a bus error killing node.
|
|
|
|
see https://github.com/google/brotli/issues/1159
|
|
|
|
diff --git a/src/node_zlib.cc b/src/node_zlib.cc
|
|
index 90307cd4984ae5aa55386f2980ad9cd540322dfd..6f12b5034d1a98da50c064cf2cfdf12fc88137eb 100644
|
|
--- a/src/node_zlib.cc
|
|
+++ b/src/node_zlib.cc
|
|
@@ -493,7 +493,8 @@ class CompressionStream : public AsyncWrap, public ThreadPoolWork {
|
|
}
|
|
|
|
static void* AllocForBrotli(void* data, size_t size) {
|
|
- size += sizeof(size_t);
|
|
+ constexpr size_t offset = std::max(sizeof(size_t), alignof(max_align_t));
|
|
+ size += offset;
|
|
CompressionStream* ctx = static_cast<CompressionStream*>(data);
|
|
char* memory = UncheckedMalloc(size);
|
|
if (memory == nullptr) [[unlikely]] {
|
|
@@ -502,7 +503,7 @@ class CompressionStream : public AsyncWrap, public ThreadPoolWork {
|
|
*reinterpret_cast<size_t*>(memory) = size;
|
|
ctx->unreported_allocations_.fetch_add(size,
|
|
std::memory_order_relaxed);
|
|
- return memory + sizeof(size_t);
|
|
+ return memory + offset;
|
|
}
|
|
|
|
static void FreeForZlib(void* data, void* pointer) {
|
|
@@ -510,7 +511,8 @@ class CompressionStream : public AsyncWrap, public ThreadPoolWork {
|
|
return;
|
|
}
|
|
CompressionStream* ctx = static_cast<CompressionStream*>(data);
|
|
- char* real_pointer = static_cast<char*>(pointer) - sizeof(size_t);
|
|
+ constexpr size_t offset = std::max(sizeof(size_t), alignof(max_align_t));
|
|
+ char* real_pointer = static_cast<char*>(pointer) - offset;
|
|
size_t real_size = *reinterpret_cast<size_t*>(real_pointer);
|
|
ctx->unreported_allocations_.fetch_sub(real_size,
|
|
std::memory_order_relaxed);
|