From f6165d23e400fb0108ec477c06ce09ef69d9b2a5 Mon Sep 17 00:00:00 2001
From: Alexander Alashkin <alexander.alashkin@cesanta.com>
Date: Wed, 16 Nov 2016 18:24:12 +0100
Subject: [PATCH] Fix stack overflow in mg_hexdump
PUBLISHED_FROM=5025692f3f4593b3ea38af51f8f49e1ac4df6b88
---
mongoose.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/mongoose.c b/mongoose.c
index fef0251b1..39902172a 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -8888,6 +8888,11 @@ struct mg_connection *mg_connect_ws(struct mg_mgr *mgr,
/* Amalgamated: #include "mongoose/src/internal.h" */
/* Amalgamated: #include "mongoose/src/util.h" */
+/* For platforms with limited libc */
+#ifndef MAX
+#define MAX(a,b) ((a) > (b)? (a): (b))
+#endif
+
const char *mg_skip(const char *s, const char *end, const char *delims,
struct mg_str *v) {
v->p = s;
@@ -9056,19 +9061,19 @@ int mg_hexdump(const void *buf, int len, char *dst, int dst_len) {
for (i = 0; i < len; i++) {
idx = i % 16;
if (idx == 0) {
- if (i > 0) n += snprintf(dst + n, dst_len - n, " %s\n", ascii);
- n += snprintf(dst + n, dst_len - n, "%04x ", i);
+ if (i > 0) n += snprintf(dst + n, MAX(dst_len - n, 0), " %s\n", ascii);
+ n += snprintf(dst + n, MAX(dst_len - n, 0), "%04x ", i);
}
if (dst_len - n < 0) {
return n;
}
- n += snprintf(dst + n, dst_len - n, " %02x", p[i]);
+ n += snprintf(dst + n, MAX(dst_len - n, 0), " %02x", p[i]);
ascii[idx] = p[i] < 0x20 || p[i] > 0x7e ? '.' : p[i];
ascii[idx + 1] = '\0';
}
- while (i++ % 16) n += snprintf(dst + n, dst_len - n, "%s", " ");
- n += snprintf(dst + n, dst_len - n, " %s\n\n", ascii);
+ while (i++ % 16) n += snprintf(dst + n, MAX(dst_len - n, 0), "%s", " ");
+ n += snprintf(dst + n, MAX(dst_len - n, 0), " %s\n\n", ascii);
return n;
}
--
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