diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/buffer.c | 26 | ||||
| -rw-r--r-- | src/buffer.h | 3 |
2 files changed, 22 insertions, 7 deletions
diff --git a/src/buffer.c b/src/buffer.c index 8fb2652..d39828e 100644 --- a/src/buffer.c +++ b/src/buffer.c @@ -15,7 +15,7 @@ unsigned char cmark_strbuf__initbuf[1]; #define ENSURE_SIZE(b, d) \ - if ((d) > b->asize) \ + if ((d) >= b->asize) \ cmark_strbuf_grow(b, (d)); \ #ifndef MIN @@ -33,11 +33,16 @@ void cmark_strbuf_init(cmark_strbuf *buf, bufsize_t initial_size) cmark_strbuf_grow(buf, initial_size); } +void cmark_strbuf_overflow_err() { + fprintf(stderr, "String buffer overflow"); + abort(); +} + void cmark_strbuf_grow(cmark_strbuf *buf, bufsize_t target_size) { unsigned char *new_ptr; - if (target_size <= buf->asize) + if (target_size < buf->asize) return; if (buf->asize == 0) { @@ -50,12 +55,20 @@ void cmark_strbuf_grow(cmark_strbuf *buf, bufsize_t target_size) * complexity on append operations. */ size_t new_size = (size_t)target_size + (size_t)target_size / 2; + /* Account for terminating null byte. */ + new_size += 1; + /* round allocation up to multiple of 8 */ new_size = (new_size + 7) & ~7; if (new_size < (size_t)target_size /* Integer overflow. */ || new_size > BUFSIZE_MAX /* Truncation overflow. */ ) { + if (target_size >= BUFSIZE_MAX) { + /* No space for terminating null byte. */ + cmark_strbuf_overflow_err(); + return; /* unreachable */ + } /* Oversize by the maximum possible amount. */ new_size = BUFSIZE_MAX; } @@ -105,8 +118,7 @@ void cmark_strbuf_set(cmark_strbuf *buf, const unsigned char *data, bufsize_t le cmark_strbuf_clear(buf); } else { if (data != buf->ptr) { - // TODO: Check for overflow. - ENSURE_SIZE(buf, len + 1); + ENSURE_SIZE(buf, len); memmove(buf->ptr, data, len); } buf->size = len; @@ -123,7 +135,7 @@ void cmark_strbuf_sets(cmark_strbuf *buf, const char *string) void cmark_strbuf_putc(cmark_strbuf *buf, int c) { // TODO: Check for overflow. - ENSURE_SIZE(buf, buf->size + 2); + ENSURE_SIZE(buf, buf->size + 1); buf->ptr[buf->size++] = c; buf->ptr[buf->size] = '\0'; } @@ -134,7 +146,7 @@ void cmark_strbuf_put(cmark_strbuf *buf, const unsigned char *data, bufsize_t le return; // TODO: Check for overflow. - ENSURE_SIZE(buf, buf->size + len + 1); + ENSURE_SIZE(buf, buf->size + len); memmove(buf->ptr + buf->size, data, len); buf->size += len; buf->ptr[buf->size] = '\0'; @@ -182,7 +194,7 @@ void cmark_strbuf_vprintf(cmark_strbuf *buf, const char *format, va_list ap) } // TODO: Check for overflow. - ENSURE_SIZE(buf, buf->size + len + 1); + ENSURE_SIZE(buf, buf->size + len); } } diff --git a/src/buffer.h b/src/buffer.h index 99e6feb..526276d 100644 --- a/src/buffer.h +++ b/src/buffer.h @@ -72,6 +72,9 @@ void cmark_strbuf_trim(cmark_strbuf *buf); void cmark_strbuf_normalize_whitespace(cmark_strbuf *s); void cmark_strbuf_unescape(cmark_strbuf *s); +/* Print error and abort. */ +void cmark_strbuf_overflow_err(void); + #ifdef __cplusplus } #endif |