Mercurial > hg > nginx
diff src/http/ngx_http_write_filter_module.c @ 7401:a7ff19afbb14
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.
| author | Maxim Dounin <mdounin@mdounin.ru> |
|---|---|
| date | Mon, 26 Nov 2018 18:29:56 +0300 |
| parents | f01ab2dbcfdc |
| children | c19ca381b2e6 |
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--- a/src/http/ngx_http_write_filter_module.c +++ b/src/http/ngx_http_write_filter_module.c @@ -80,7 +80,6 @@ ngx_http_write_filter(ngx_http_request_t 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_http_write_filter(ngx_http_request_t 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 @@ ngx_http_write_filter(ngx_http_request_t 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_http_write_filter(ngx_http_request_t 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);