view src/stream/ngx_stream_upstream_zone_module.c @ 7667:1ece2ac2555a

OCSP: fixed use-after-free on error. When validating second and further certificates, ssl callback could be called twice to report the error. After the first call client connection is terminated and its memory is released. Prior to the second call and in it released connection memory is accessed. Errors triggering this behavior: - failure to create the request - failure to start resolving OCSP responder name - failure to start connecting to the OCSP responder The fix is to rearrange the code to eliminate the second call.
author Roman Arutyunyan <arut@nginx.com>
date Mon, 15 Jun 2020 20:17:16 +0300
parents 3b1b81e248bc
children
line wrap: on
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/*
 * Copyright (C) Ruslan Ermilov
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_stream.h>


static char *ngx_stream_upstream_zone(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static ngx_int_t ngx_stream_upstream_init_zone(ngx_shm_zone_t *shm_zone,
    void *data);
static ngx_stream_upstream_rr_peers_t *ngx_stream_upstream_zone_copy_peers(
    ngx_slab_pool_t *shpool, ngx_stream_upstream_srv_conf_t *uscf);
static ngx_stream_upstream_rr_peer_t *ngx_stream_upstream_zone_copy_peer(
    ngx_stream_upstream_rr_peers_t *peers, ngx_stream_upstream_rr_peer_t *src);


static ngx_command_t  ngx_stream_upstream_zone_commands[] = {

    { ngx_string("zone"),
      NGX_STREAM_UPS_CONF|NGX_CONF_TAKE12,
      ngx_stream_upstream_zone,
      0,
      0,
      NULL },

      ngx_null_command
};


static ngx_stream_module_t  ngx_stream_upstream_zone_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_upstream_zone_module = {
    NGX_MODULE_V1,
    &ngx_stream_upstream_zone_module_ctx,  /* module context */
    ngx_stream_upstream_zone_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 char *
ngx_stream_upstream_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ssize_t                           size;
    ngx_str_t                        *value;
    ngx_stream_upstream_srv_conf_t   *uscf;
    ngx_stream_upstream_main_conf_t  *umcf;

    uscf = ngx_stream_conf_get_module_srv_conf(cf, ngx_stream_upstream_module);
    umcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_upstream_module);

    value = cf->args->elts;

    if (!value[1].len) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid zone name \"%V\"", &value[1]);
        return NGX_CONF_ERROR;
    }

    if (cf->args->nelts == 3) {
        size = ngx_parse_size(&value[2]);

        if (size == NGX_ERROR) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "invalid zone size \"%V\"", &value[2]);
            return NGX_CONF_ERROR;
        }

        if (size < (ssize_t) (8 * ngx_pagesize)) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "zone \"%V\" is too small", &value[1]);
            return NGX_CONF_ERROR;
        }

    } else {
        size = 0;
    }

    uscf->shm_zone = ngx_shared_memory_add(cf, &value[1], size,
                                           &ngx_stream_upstream_module);
    if (uscf->shm_zone == NULL) {
        return NGX_CONF_ERROR;
    }

    uscf->shm_zone->init = ngx_stream_upstream_init_zone;
    uscf->shm_zone->data = umcf;

    uscf->shm_zone->noreuse = 1;

    return NGX_CONF_OK;
}


static ngx_int_t
ngx_stream_upstream_init_zone(ngx_shm_zone_t *shm_zone, void *data)
{
    size_t                            len;
    ngx_uint_t                        i;
    ngx_slab_pool_t                  *shpool;
    ngx_stream_upstream_rr_peers_t   *peers, **peersp;
    ngx_stream_upstream_srv_conf_t   *uscf, **uscfp;
    ngx_stream_upstream_main_conf_t  *umcf;

    shpool = (ngx_slab_pool_t *) shm_zone->shm.addr;
    umcf = shm_zone->data;
    uscfp = umcf->upstreams.elts;

    if (shm_zone->shm.exists) {
        peers = shpool->data;

        for (i = 0; i < umcf->upstreams.nelts; i++) {
            uscf = uscfp[i];

            if (uscf->shm_zone != shm_zone) {
                continue;
            }

            uscf->peer.data = peers;
            peers = peers->zone_next;
        }

        return NGX_OK;
    }

    len = sizeof(" in upstream zone \"\"") + shm_zone->shm.name.len;

    shpool->log_ctx = ngx_slab_alloc(shpool, len);
    if (shpool->log_ctx == NULL) {
        return NGX_ERROR;
    }

    ngx_sprintf(shpool->log_ctx, " in upstream zone \"%V\"%Z",
                &shm_zone->shm.name);


    /* copy peers to shared memory */

    peersp = (ngx_stream_upstream_rr_peers_t **) (void *) &shpool->data;

    for (i = 0; i < umcf->upstreams.nelts; i++) {
        uscf = uscfp[i];

        if (uscf->shm_zone != shm_zone) {
            continue;
        }

        peers = ngx_stream_upstream_zone_copy_peers(shpool, uscf);
        if (peers == NULL) {
            return NGX_ERROR;
        }

        *peersp = peers;
        peersp = &peers->zone_next;
    }

    return NGX_OK;
}


static ngx_stream_upstream_rr_peers_t *
ngx_stream_upstream_zone_copy_peers(ngx_slab_pool_t *shpool,
    ngx_stream_upstream_srv_conf_t *uscf)
{
    ngx_str_t                       *name;
    ngx_stream_upstream_rr_peer_t   *peer, **peerp;
    ngx_stream_upstream_rr_peers_t  *peers, *backup;

    peers = ngx_slab_alloc(shpool, sizeof(ngx_stream_upstream_rr_peers_t));
    if (peers == NULL) {
        return NULL;
    }

    ngx_memcpy(peers, uscf->peer.data, sizeof(ngx_stream_upstream_rr_peers_t));

    name = ngx_slab_alloc(shpool, sizeof(ngx_str_t));
    if (name == NULL) {
        return NULL;
    }

    name->data = ngx_slab_alloc(shpool, peers->name->len);
    if (name->data == NULL) {
        return NULL;
    }

    ngx_memcpy(name->data, peers->name->data, peers->name->len);
    name->len = peers->name->len;

    peers->name = name;

    peers->shpool = shpool;

    for (peerp = &peers->peer; *peerp; peerp = &peer->next) {
        /* pool is unlocked */
        peer = ngx_stream_upstream_zone_copy_peer(peers, *peerp);
        if (peer == NULL) {
            return NULL;
        }

        *peerp = peer;
    }

    if (peers->next == NULL) {
        goto done;
    }

    backup = ngx_slab_alloc(shpool, sizeof(ngx_stream_upstream_rr_peers_t));
    if (backup == NULL) {
        return NULL;
    }

    ngx_memcpy(backup, peers->next, sizeof(ngx_stream_upstream_rr_peers_t));

    backup->name = name;

    backup->shpool = shpool;

    for (peerp = &backup->peer; *peerp; peerp = &peer->next) {
        /* pool is unlocked */
        peer = ngx_stream_upstream_zone_copy_peer(backup, *peerp);
        if (peer == NULL) {
            return NULL;
        }

        *peerp = peer;
    }

    peers->next = backup;

done:

    uscf->peer.data = peers;

    return peers;
}


static ngx_stream_upstream_rr_peer_t *
ngx_stream_upstream_zone_copy_peer(ngx_stream_upstream_rr_peers_t *peers,
    ngx_stream_upstream_rr_peer_t *src)
{
    ngx_slab_pool_t                *pool;
    ngx_stream_upstream_rr_peer_t  *dst;

    pool = peers->shpool;

    dst = ngx_slab_calloc_locked(pool, sizeof(ngx_stream_upstream_rr_peer_t));
    if (dst == NULL) {
        return NULL;
    }

    if (src) {
        ngx_memcpy(dst, src, sizeof(ngx_stream_upstream_rr_peer_t));
        dst->sockaddr = NULL;
        dst->name.data = NULL;
        dst->server.data = NULL;
    }

    dst->sockaddr = ngx_slab_calloc_locked(pool, sizeof(ngx_sockaddr_t));
    if (dst->sockaddr == NULL) {
        goto failed;
    }

    dst->name.data = ngx_slab_calloc_locked(pool, NGX_SOCKADDR_STRLEN);
    if (dst->name.data == NULL) {
        goto failed;
    }

    if (src) {
        ngx_memcpy(dst->sockaddr, src->sockaddr, src->socklen);
        ngx_memcpy(dst->name.data, src->name.data, src->name.len);

        dst->server.data = ngx_slab_alloc_locked(pool, src->server.len);
        if (dst->server.data == NULL) {
            goto failed;
        }

        ngx_memcpy(dst->server.data, src->server.data, src->server.len);
    }

    return dst;

failed:

    if (dst->server.data) {
        ngx_slab_free_locked(pool, dst->server.data);
    }

    if (dst->name.data) {
        ngx_slab_free_locked(pool, dst->name.data);
    }

    if (dst->sockaddr) {
        ngx_slab_free_locked(pool, dst->sockaddr);
    }

    ngx_slab_free_locked(pool, dst);

    return NULL;
}