From 0925ae79a1b49ee3d63e542dd74acdb0c580c6c9 Mon Sep 17 00:00:00 2001
From: Yorhel <git@yorhel.nl>
Date: Wed, 19 Mar 2025 17:33:10 +0100
Subject: [PATCH] XS: Ensure created Perl strings are nul-terminated

Most of these are binary strings and shouldn't be interpreted as C
strings in the first place, but better be safe in case they are, anyway.
The lack of nul-termination of FU::Pg `$hex` strings was more likely to
be problematic.
---
 c/compress.c | 3 +++
 c/fdpass.c   | 1 +
 c/pgtypes.c  | 1 +
 3 files changed, 5 insertions(+)

diff --git a/c/compress.c b/c/compress.c
index 20a59be..da986a3 100644
--- a/c/compress.c
+++ b/c/compress.c
@@ -87,6 +87,7 @@ static SV *fugz_compress_ld(pTHX_ int level, const char *bytes, size_t inlen) {
     size_t len = libdeflate_gzip_compress(fugz_ld_ctx, bytes, inlen, SvPVX(out), outlen);
     if (!len) fu_confess("Libdeflate compression failed"); /* Shouldn't happen */
     SvCUR_set(out, len);
+    SvPVX(out)[len] = 0;
     return out;
 }
 
@@ -110,6 +111,7 @@ static SV *fugz_compress_zlib(pTHX_ int level, const char *bytes, size_t inlen)
     if ((r = deflate(&stream, 4)) != 1) fu_confess("Zlib compression failed (%d)", r);
 
     SvCUR_set(out, stream.total_out);
+    SvPVX(out)[stream.total_out] = 0;
     deflateEnd(&stream);
     return out;
 }
@@ -157,5 +159,6 @@ static SV *fubr_compress(pTHX_ IV level, SV *in) {
     if (!BrotliEncoderCompress(level, 22, BROTLI_MODE_GENERIC, inlen, bytes, &outlen, SvPVX(out)))
         fu_confess("Brotli compression failed");
     SvCUR_set(out, outlen);
+    SvPVX(out)[outlen] = 0;
     return out;
 }
diff --git a/c/fdpass.c b/c/fdpass.c
index 74a1229..ae4b141 100644
--- a/c/fdpass.c
+++ b/c/fdpass.c
@@ -71,6 +71,7 @@ static int fufdpass_recv(pTHX_ I32 ax, int socket, size_t len) {
     }
 
     SvCUR_set(buf, r);
+    SvPVX(buf)[r] = 0;
     ST(1) = buf;
     return 2;
 }
diff --git a/c/pgtypes.c b/c/pgtypes.c
index 6fb8835..b307cc0 100644
--- a/c/pgtypes.c
+++ b/c/pgtypes.c
@@ -166,6 +166,7 @@ RECVFN(hex) {
         *out++ = PL_hexdigit[(in[i] >> 4) & 0x0f];
         *out++ = PL_hexdigit[in[i] & 0x0f];
     }
+    *out = 0;
     SvCUR_set(r, len * 2);
     return r;
 }