Mercurial > hg > nginx
view src/stream/ngx_stream_split_clients_module.c @ 7094:c7d4017c8876
Secure link: fixed stack buffer overflow.
When secure link checksum has length of 23 or 24 bytes, decoded base64 value
could occupy 17 or 18 bytes which is more than 16 bytes previously allocated
for it on stack. The buffer overflow does not have any security implications
since only one local variable was corrupted and this variable was not used in
this case.
The fix is to increase buffer size up to 18 bytes. Useless buffer size
initialization is removed as well.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Tue, 22 Aug 2017 21:22:59 +0300 |
parents | 787dcc15b802 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> typedef struct { uint32_t percent; ngx_stream_variable_value_t value; } ngx_stream_split_clients_part_t; typedef struct { ngx_stream_complex_value_t value; ngx_array_t parts; } ngx_stream_split_clients_ctx_t; static char *ngx_conf_split_clients_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_stream_split_clients(ngx_conf_t *cf, ngx_command_t *dummy, void *conf); static ngx_command_t ngx_stream_split_clients_commands[] = { { ngx_string("split_clients"), NGX_STREAM_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_TAKE2, ngx_conf_split_clients_block, NGX_STREAM_MAIN_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_stream_module_t ngx_stream_split_clients_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL /* merge server configuration */ }; ngx_module_t ngx_stream_split_clients_module = { NGX_MODULE_V1, &ngx_stream_split_clients_module_ctx, /* module context */ ngx_stream_split_clients_commands, /* module directives */ NGX_STREAM_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_int_t ngx_stream_split_clients_variable(ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data) { ngx_stream_split_clients_ctx_t *ctx = (ngx_stream_split_clients_ctx_t *) data; uint32_t hash; ngx_str_t val; ngx_uint_t i; ngx_stream_split_clients_part_t *part; *v = ngx_stream_variable_null_value; if (ngx_stream_complex_value(s, &ctx->value, &val) != NGX_OK) { return NGX_OK; } hash = ngx_murmur_hash2(val.data, val.len); part = ctx->parts.elts; for (i = 0; i < ctx->parts.nelts; i++) { ngx_log_debug2(NGX_LOG_DEBUG_STREAM, s->connection->log, 0, "stream split: %uD %uD", hash, part[i].percent); if (hash < part[i].percent || part[i].percent == 0) { *v = part[i].value; return NGX_OK; } } return NGX_OK; } static char * ngx_conf_split_clients_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { char *rv; uint32_t sum, last; ngx_str_t *value, name; ngx_uint_t i; ngx_conf_t save; ngx_stream_variable_t *var; ngx_stream_split_clients_ctx_t *ctx; ngx_stream_split_clients_part_t *part; ngx_stream_compile_complex_value_t ccv; ctx = ngx_pcalloc(cf->pool, sizeof(ngx_stream_split_clients_ctx_t)); if (ctx == NULL) { return NGX_CONF_ERROR; } value = cf->args->elts; ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[1]; ccv.complex_value = &ctx->value; if (ngx_stream_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } name = value[2]; if (name.data[0] != '$') { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid variable name \"%V\"", &name); return NGX_CONF_ERROR; } name.len--; name.data++; var = ngx_stream_add_variable(cf, &name, NGX_STREAM_VAR_CHANGEABLE); if (var == NULL) { return NGX_CONF_ERROR; } var->get_handler = ngx_stream_split_clients_variable; var->data = (uintptr_t) ctx; if (ngx_array_init(&ctx->parts, cf->pool, 2, sizeof(ngx_stream_split_clients_part_t)) != NGX_OK) { return NGX_CONF_ERROR; } save = *cf; cf->ctx = ctx; cf->handler = ngx_stream_split_clients; cf->handler_conf = conf; rv = ngx_conf_parse(cf, NULL); *cf = save; if (rv != NGX_CONF_OK) { return rv; } sum = 0; last = 0; part = ctx->parts.elts; for (i = 0; i < ctx->parts.nelts; i++) { sum = part[i].percent ? sum + part[i].percent : 10000; if (sum > 10000) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "percent total is greater than 100%%"); return NGX_CONF_ERROR; } if (part[i].percent) { last += part[i].percent * (uint64_t) 0xffffffff / 10000; part[i].percent = last; } } return rv; } static char * ngx_stream_split_clients(ngx_conf_t *cf, ngx_command_t *dummy, void *conf) { ngx_int_t n; ngx_str_t *value; ngx_stream_split_clients_ctx_t *ctx; ngx_stream_split_clients_part_t *part; ctx = cf->ctx; value = cf->args->elts; part = ngx_array_push(&ctx->parts); if (part == NULL) { return NGX_CONF_ERROR; } if (value[0].len == 1 && value[0].data[0] == '*') { part->percent = 0; } else { if (value[0].len == 0 || value[0].data[value[0].len - 1] != '%') { goto invalid; } n = ngx_atofp(value[0].data, value[0].len - 1, 2); if (n == NGX_ERROR || n == 0) { goto invalid; } part->percent = (uint32_t) n; } part->value.len = value[1].len; part->value.valid = 1; part->value.no_cacheable = 0; part->value.not_found = 0; part->value.data = value[1].data; return NGX_CONF_OK; invalid: ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid percent value \"%V\"", &value[0]); return NGX_CONF_ERROR; }