Mercurial > hg > nginx
view src/http/v2/ngx_http_v2_encode.c @ 7566:571383f75a9a
Resolver: fixed possible use-after-free while resolving PTR.
Previously, if a response to the PTR request was cached, and ngx_resolver_dup()
failed to allocate memory for the resulting name, then the original node was
freed but left in expire_queue. A subsequent address resolving would end up
in a use-after-free memory access of the node either in ngx_resolver_expire()
or ngx_resolver_process_ptr(), when accessing it through expire_queue.
The fix is to leave the resolver node intact.
author | Sergey Kandaurov <pluknet@nginx.com> |
---|---|
date | Tue, 10 Sep 2019 15:42:34 +0300 |
parents | 87e9e4aabf1b |
children | 336084ff943b |
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/* * Copyright (C) Nginx, Inc. * Copyright (C) Valentin V. Bartenev */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> static u_char *ngx_http_v2_write_int(u_char *pos, ngx_uint_t prefix, ngx_uint_t value); u_char * ngx_http_v2_string_encode(u_char *dst, u_char *src, size_t len, u_char *tmp, ngx_uint_t lower) { size_t hlen; hlen = ngx_http_v2_huff_encode(src, len, tmp, lower); if (hlen > 0) { *dst = NGX_HTTP_V2_ENCODE_HUFF; dst = ngx_http_v2_write_int(dst, ngx_http_v2_prefix(7), hlen); return ngx_cpymem(dst, tmp, hlen); } *dst = NGX_HTTP_V2_ENCODE_RAW; dst = ngx_http_v2_write_int(dst, ngx_http_v2_prefix(7), len); if (lower) { ngx_strlow(dst, src, len); return dst + len; } return ngx_cpymem(dst, src, len); } static u_char * ngx_http_v2_write_int(u_char *pos, ngx_uint_t prefix, ngx_uint_t value) { if (value < prefix) { *pos++ |= value; return pos; } *pos++ |= prefix; value -= prefix; while (value >= 128) { *pos++ = value % 128 + 128; value /= 128; } *pos++ = (u_char) value; return pos; }