Negative size buffers detection.
In the past, there were several security issues which resulted in
worker process memory disclosure due to buffers with negative size.
It looks reasonable to check for such buffers in various places,
much like we already check for zero size buffers.
While here, removed "#if 1 / #endif" around zero size buffer checks.
It looks highly unlikely that we'll disable these checks anytime soon.
diff --git a/src/core/ngx_output_chain.c b/src/core/ngx_output_chain.c
index 7f5dc78..5c3dbe8 100644
--- a/src/core/ngx_output_chain.c
+++ b/src/core/ngx_output_chain.c
@@ -126,6 +126,26 @@
continue;
}
+ if (bsize < 0) {
+
+ ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, 0,
+ "negative size buf in output "
+ "t:%d r:%d f:%d %p %p-%p %p %O-%O",
+ ctx->in->buf->temporary,
+ ctx->in->buf->recycled,
+ ctx->in->buf->in_file,
+ ctx->in->buf->start,
+ ctx->in->buf->pos,
+ ctx->in->buf->last,
+ ctx->in->buf->file,
+ ctx->in->buf->file_pos,
+ ctx->in->buf->file_last);
+
+ ngx_debug_point();
+
+ return NGX_ERROR;
+ }
+
if (ngx_output_chain_as_is(ctx, ctx->in->buf)) {
/* move the chain link to the output chain */
@@ -665,7 +685,6 @@
for (size = 0; in; in = in->next) {
-#if 1
if (ngx_buf_size(in->buf) == 0 && !ngx_buf_special(in->buf)) {
ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, 0,
@@ -685,7 +704,26 @@
continue;
}
-#endif
+
+ if (ngx_buf_size(in->buf) < 0) {
+
+ ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, 0,
+ "negative size buf in chain writer "
+ "t:%d r:%d f:%d %p %p-%p %p %O-%O",
+ in->buf->temporary,
+ in->buf->recycled,
+ in->buf->in_file,
+ in->buf->start,
+ in->buf->pos,
+ in->buf->last,
+ in->buf->file,
+ in->buf->file_pos,
+ in->buf->file_last);
+
+ ngx_debug_point();
+
+ return NGX_ERROR;
+ }
size += ngx_buf_size(in->buf);
@@ -709,7 +747,6 @@
for (cl = ctx->out; cl; cl = cl->next) {
-#if 1
if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) {
ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, 0,
@@ -729,7 +766,26 @@
continue;
}
-#endif
+
+ if (ngx_buf_size(cl->buf) < 0) {
+
+ ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, 0,
+ "negative size buf in chain writer "
+ "t:%d r:%d f:%d %p %p-%p %p %O-%O",
+ cl->buf->temporary,
+ cl->buf->recycled,
+ cl->buf->in_file,
+ cl->buf->start,
+ cl->buf->pos,
+ cl->buf->last,
+ cl->buf->file,
+ cl->buf->file_pos,
+ cl->buf->file_last);
+
+ ngx_debug_point();
+
+ return NGX_ERROR;
+ }
size += ngx_buf_size(cl->buf);
}
diff --git a/src/http/ngx_http_write_filter_module.c b/src/http/ngx_http_write_filter_module.c
index 0036231..3f18d76 100644
--- a/src/http/ngx_http_write_filter_module.c
+++ b/src/http/ngx_http_write_filter_module.c
@@ -80,7 +80,6 @@
cl->buf->file_pos,
cl->buf->file_last - cl->buf->file_pos);
-#if 1
if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) {
ngx_log_error(NGX_LOG_ALERT, c->log, 0,
"zero size buf in writer "
@@ -98,7 +97,24 @@
ngx_debug_point();
return NGX_ERROR;
}
-#endif
+
+ if (ngx_buf_size(cl->buf) < 0) {
+ ngx_log_error(NGX_LOG_ALERT, c->log, 0,
+ "negative size buf in writer "
+ "t:%d r:%d f:%d %p %p-%p %p %O-%O",
+ cl->buf->temporary,
+ cl->buf->recycled,
+ cl->buf->in_file,
+ cl->buf->start,
+ cl->buf->pos,
+ cl->buf->last,
+ cl->buf->file,
+ cl->buf->file_pos,
+ cl->buf->file_last);
+
+ ngx_debug_point();
+ return NGX_ERROR;
+ }
size += ngx_buf_size(cl->buf);
@@ -136,7 +152,6 @@
cl->buf->file_pos,
cl->buf->file_last - cl->buf->file_pos);
-#if 1
if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) {
ngx_log_error(NGX_LOG_ALERT, c->log, 0,
"zero size buf in writer "
@@ -154,7 +169,24 @@
ngx_debug_point();
return NGX_ERROR;
}
-#endif
+
+ if (ngx_buf_size(cl->buf) < 0) {
+ ngx_log_error(NGX_LOG_ALERT, c->log, 0,
+ "negative size buf in writer "
+ "t:%d r:%d f:%d %p %p-%p %p %O-%O",
+ cl->buf->temporary,
+ cl->buf->recycled,
+ cl->buf->in_file,
+ cl->buf->start,
+ cl->buf->pos,
+ cl->buf->last,
+ cl->buf->file,
+ cl->buf->file_pos,
+ cl->buf->file_last);
+
+ ngx_debug_point();
+ return NGX_ERROR;
+ }
size += ngx_buf_size(cl->buf);
diff --git a/src/stream/ngx_stream_write_filter_module.c b/src/stream/ngx_stream_write_filter_module.c
index 8fdcd37..24326c6 100644
--- a/src/stream/ngx_stream_write_filter_module.c
+++ b/src/stream/ngx_stream_write_filter_module.c
@@ -104,7 +104,6 @@
cl->buf->file_pos,
cl->buf->file_last - cl->buf->file_pos);
-#if 1
if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) {
ngx_log_error(NGX_LOG_ALERT, c->log, 0,
"zero size buf in writer "
@@ -122,7 +121,24 @@
ngx_debug_point();
return NGX_ERROR;
}
-#endif
+
+ if (ngx_buf_size(cl->buf) < 0) {
+ ngx_log_error(NGX_LOG_ALERT, c->log, 0,
+ "negative size buf in writer "
+ "t:%d r:%d f:%d %p %p-%p %p %O-%O",
+ cl->buf->temporary,
+ cl->buf->recycled,
+ cl->buf->in_file,
+ cl->buf->start,
+ cl->buf->pos,
+ cl->buf->last,
+ cl->buf->file,
+ cl->buf->file_pos,
+ cl->buf->file_last);
+
+ ngx_debug_point();
+ return NGX_ERROR;
+ }
size += ngx_buf_size(cl->buf);
@@ -160,7 +176,6 @@
cl->buf->file_pos,
cl->buf->file_last - cl->buf->file_pos);
-#if 1
if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) {
ngx_log_error(NGX_LOG_ALERT, c->log, 0,
"zero size buf in writer "
@@ -178,7 +193,24 @@
ngx_debug_point();
return NGX_ERROR;
}
-#endif
+
+ if (ngx_buf_size(cl->buf) < 0) {
+ ngx_log_error(NGX_LOG_ALERT, c->log, 0,
+ "negative size buf in writer "
+ "t:%d r:%d f:%d %p %p-%p %p %O-%O",
+ cl->buf->temporary,
+ cl->buf->recycled,
+ cl->buf->in_file,
+ cl->buf->start,
+ cl->buf->pos,
+ cl->buf->last,
+ cl->buf->file,
+ cl->buf->file_pos,
+ cl->buf->file_last);
+
+ ngx_debug_point();
+ return NGX_ERROR;
+ }
size += ngx_buf_size(cl->buf);
