Mercurial > hg > nginx
view src/mail/ngx_mail_imap_module.c @ 9112:d59277dd3d8c
QUIC: fixed post-close use-after-free.
Previously, ngx_quic_close_connection() could be called in a way that QUIC
connection was accessed after the call. In most cases the connection is not
closed right away, but close timeout is scheduled. However, it's not always
the case. Also, if the close process started earlier for a different reason,
calling ngx_quic_close_connection() may actually close the connection. The
connection object should not be accessed after that.
Now, when possible, return statement is added to eliminate post-close connection
object access. In other places ngx_quic_close_connection() is substituted with
posting close event.
Also, the new way of closing connection in ngx_quic_stream_cleanup_handler()
fixes another problem in this function. Previously it passed stream connection
instead of QUIC connection to ngx_quic_close_connection(). This could result
in incomplete connection shutdown. One consequence of that could be that QUIC
streams were freed without shutting down their application contexts. This could
result in another use-after-free.
Found by Coverity (CID 1530402).
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Mon, 22 May 2023 15:59:42 +0400 |
parents | dc955d274130 |
children | 4538c1ffb0f8 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #include <ngx_mail.h> #include <ngx_mail_imap_module.h> static void *ngx_mail_imap_create_srv_conf(ngx_conf_t *cf); static char *ngx_mail_imap_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_str_t ngx_mail_imap_default_capabilities[] = { ngx_string("IMAP4"), ngx_string("IMAP4rev1"), ngx_string("UIDPLUS"), ngx_null_string }; static ngx_conf_bitmask_t ngx_mail_imap_auth_methods[] = { { ngx_string("plain"), NGX_MAIL_AUTH_PLAIN_ENABLED }, { ngx_string("login"), NGX_MAIL_AUTH_LOGIN_ENABLED }, { ngx_string("cram-md5"), NGX_MAIL_AUTH_CRAM_MD5_ENABLED }, { ngx_string("external"), NGX_MAIL_AUTH_EXTERNAL_ENABLED }, { ngx_null_string, 0 } }; static ngx_str_t ngx_mail_imap_auth_methods_names[] = { ngx_string("AUTH=PLAIN"), ngx_string("AUTH=LOGIN"), ngx_null_string, /* APOP */ ngx_string("AUTH=CRAM-MD5"), ngx_string("AUTH=EXTERNAL"), ngx_null_string /* NONE */ }; static ngx_mail_protocol_t ngx_mail_imap_protocol = { ngx_string("imap"), ngx_string("\x04imap"), { 143, 993, 0, 0 }, NGX_MAIL_IMAP_PROTOCOL, ngx_mail_imap_init_session, ngx_mail_imap_init_protocol, ngx_mail_imap_parse_command, ngx_mail_imap_auth_state, ngx_string("* BAD internal server error" CRLF), ngx_string("* BYE SSL certificate error" CRLF), ngx_string("* BYE No required SSL certificate" CRLF) }; static ngx_command_t ngx_mail_imap_commands[] = { { ngx_string("imap_client_buffer"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_size_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_imap_srv_conf_t, client_buffer_size), NULL }, { ngx_string("imap_capabilities"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE, ngx_mail_capabilities, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_imap_srv_conf_t, capabilities), NULL }, { ngx_string("imap_auth"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE, ngx_conf_set_bitmask_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_imap_srv_conf_t, auth_methods), &ngx_mail_imap_auth_methods }, ngx_null_command }; static ngx_mail_module_t ngx_mail_imap_module_ctx = { &ngx_mail_imap_protocol, /* protocol */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_mail_imap_create_srv_conf, /* create server configuration */ ngx_mail_imap_merge_srv_conf /* merge server configuration */ }; ngx_module_t ngx_mail_imap_module = { NGX_MODULE_V1, &ngx_mail_imap_module_ctx, /* module context */ ngx_mail_imap_commands, /* module directives */ NGX_MAIL_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 void * ngx_mail_imap_create_srv_conf(ngx_conf_t *cf) { ngx_mail_imap_srv_conf_t *iscf; iscf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_imap_srv_conf_t)); if (iscf == NULL) { return NULL; } iscf->client_buffer_size = NGX_CONF_UNSET_SIZE; if (ngx_array_init(&iscf->capabilities, cf->pool, 4, sizeof(ngx_str_t)) != NGX_OK) { return NULL; } return iscf; } static char * ngx_mail_imap_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_mail_imap_srv_conf_t *prev = parent; ngx_mail_imap_srv_conf_t *conf = child; u_char *p, *auth; size_t size; ngx_str_t *c, *d; ngx_uint_t i, m; ngx_conf_merge_size_value(conf->client_buffer_size, prev->client_buffer_size, (size_t) ngx_pagesize); ngx_conf_merge_bitmask_value(conf->auth_methods, prev->auth_methods, (NGX_CONF_BITMASK_SET |NGX_MAIL_AUTH_PLAIN_ENABLED)); if (conf->capabilities.nelts == 0) { conf->capabilities = prev->capabilities; } if (conf->capabilities.nelts == 0) { for (d = ngx_mail_imap_default_capabilities; d->len; d++) { c = ngx_array_push(&conf->capabilities); if (c == NULL) { return NGX_CONF_ERROR; } *c = *d; } } size = sizeof("* CAPABILITY" CRLF) - 1; c = conf->capabilities.elts; for (i = 0; i < conf->capabilities.nelts; i++) { size += 1 + c[i].len; } for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0; m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED; m <<= 1, i++) { if (m & conf->auth_methods) { size += 1 + ngx_mail_imap_auth_methods_names[i].len; } } p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->capability.len = size; conf->capability.data = p; p = ngx_cpymem(p, "* CAPABILITY", sizeof("* CAPABILITY") - 1); for (i = 0; i < conf->capabilities.nelts; i++) { *p++ = ' '; p = ngx_cpymem(p, c[i].data, c[i].len); } auth = p; for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0; m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED; m <<= 1, i++) { if (m & conf->auth_methods) { *p++ = ' '; p = ngx_cpymem(p, ngx_mail_imap_auth_methods_names[i].data, ngx_mail_imap_auth_methods_names[i].len); } } *p++ = CR; *p = LF; size += sizeof(" STARTTLS") - 1; p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->starttls_capability.len = size; conf->starttls_capability.data = p; p = ngx_cpymem(p, conf->capability.data, conf->capability.len - (sizeof(CRLF) - 1)); p = ngx_cpymem(p, " STARTTLS", sizeof(" STARTTLS") - 1); *p++ = CR; *p = LF; size = (auth - conf->capability.data) + sizeof(CRLF) - 1 + sizeof(" STARTTLS LOGINDISABLED") - 1; p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->starttls_only_capability.len = size; conf->starttls_only_capability.data = p; p = ngx_cpymem(p, conf->capability.data, auth - conf->capability.data); p = ngx_cpymem(p, " STARTTLS LOGINDISABLED", sizeof(" STARTTLS LOGINDISABLED") - 1); *p++ = CR; *p = LF; return NGX_CONF_OK; }