Mercurial > hg > nginx
view src/event/ngx_event_acceptex.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 | bcd442b585f0 |
children | fdc3d40979b0 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> static void ngx_close_posted_connection(ngx_connection_t *c); void ngx_event_acceptex(ngx_event_t *rev) { ngx_listening_t *ls; ngx_connection_t *c; c = rev->data; ls = c->listening; c->log->handler = ngx_accept_log_error; ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "AcceptEx: %d", c->fd); if (rev->ovlp.error) { ngx_log_error(NGX_LOG_CRIT, c->log, rev->ovlp.error, "AcceptEx() %V failed", &ls->addr_text); return; } /* SO_UPDATE_ACCEPT_CONTEXT is required for shutdown() to work */ if (setsockopt(c->fd, SOL_SOCKET, SO_UPDATE_ACCEPT_CONTEXT, (char *) &ls->fd, sizeof(ngx_socket_t)) == -1) { ngx_log_error(NGX_LOG_CRIT, c->log, ngx_socket_errno, "setsockopt(SO_UPDATE_ACCEPT_CONTEXT) failed for %V", &c->addr_text); /* TODO: close socket */ return; } ngx_getacceptexsockaddrs(c->buffer->pos, ls->post_accept_buffer_size, ls->socklen + 16, ls->socklen + 16, &c->local_sockaddr, &c->local_socklen, &c->sockaddr, &c->socklen); if (ls->post_accept_buffer_size) { c->buffer->last += rev->available; c->buffer->end = c->buffer->start + ls->post_accept_buffer_size; } else { c->buffer = NULL; } if (ls->addr_ntop) { c->addr_text.data = ngx_pnalloc(c->pool, ls->addr_text_max_len); if (c->addr_text.data == NULL) { /* TODO: close socket */ return; } c->addr_text.len = ngx_sock_ntop(c->sockaddr, c->socklen, c->addr_text.data, ls->addr_text_max_len, 0); if (c->addr_text.len == 0) { /* TODO: close socket */ return; } } ngx_event_post_acceptex(ls, 1); c->number = ngx_atomic_fetch_add(ngx_connection_counter, 1); ls->handler(c); return; } ngx_int_t ngx_event_post_acceptex(ngx_listening_t *ls, ngx_uint_t n) { u_long rcvd; ngx_err_t err; ngx_log_t *log; ngx_uint_t i; ngx_event_t *rev, *wev; ngx_socket_t s; ngx_connection_t *c; for (i = 0; i < n; i++) { /* TODO: look up reused sockets */ s = ngx_socket(ls->sockaddr->sa_family, ls->type, 0); ngx_log_debug1(NGX_LOG_DEBUG_EVENT, &ls->log, 0, ngx_socket_n " s:%d", s); if (s == (ngx_socket_t) -1) { ngx_log_error(NGX_LOG_ALERT, &ls->log, ngx_socket_errno, ngx_socket_n " failed"); return NGX_ERROR; } c = ngx_get_connection(s, &ls->log); if (c == NULL) { return NGX_ERROR; } c->pool = ngx_create_pool(ls->pool_size, &ls->log); if (c->pool == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } log = ngx_palloc(c->pool, sizeof(ngx_log_t)); if (log == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } c->buffer = ngx_create_temp_buf(c->pool, ls->post_accept_buffer_size + 2 * (ls->socklen + 16)); if (c->buffer == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } c->local_sockaddr = ngx_palloc(c->pool, ls->socklen); if (c->local_sockaddr == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } c->sockaddr = ngx_palloc(c->pool, ls->socklen); if (c->sockaddr == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } *log = ls->log; c->log = log; c->recv = ngx_recv; c->send = ngx_send; c->recv_chain = ngx_recv_chain; c->send_chain = ngx_send_chain; c->listening = ls; rev = c->read; wev = c->write; rev->ovlp.event = rev; wev->ovlp.event = wev; rev->handler = ngx_event_acceptex; rev->ready = 1; wev->ready = 1; rev->log = c->log; wev->log = c->log; if (ngx_add_event(rev, 0, NGX_IOCP_IO) == NGX_ERROR) { ngx_close_posted_connection(c); return NGX_ERROR; } if (ngx_acceptex(ls->fd, s, c->buffer->pos, ls->post_accept_buffer_size, ls->socklen + 16, ls->socklen + 16, &rcvd, (LPOVERLAPPED) &rev->ovlp) == 0) { err = ngx_socket_errno; if (err != WSA_IO_PENDING) { ngx_log_error(NGX_LOG_ALERT, &ls->log, err, "AcceptEx() %V failed", &ls->addr_text); ngx_close_posted_connection(c); return NGX_ERROR; } } } return NGX_OK; } static void ngx_close_posted_connection(ngx_connection_t *c) { ngx_socket_t fd; ngx_free_connection(c); fd = c->fd; c->fd = (ngx_socket_t) -1; if (ngx_close_socket(fd) == -1) { ngx_log_error(NGX_LOG_ALERT, c->log, ngx_socket_errno, ngx_close_socket_n " failed"); } if (c->pool) { ngx_destroy_pool(c->pool); } } u_char * ngx_acceptex_log_error(ngx_log_t *log, u_char *buf, size_t len) { return ngx_snprintf(buf, len, " while posting AcceptEx() on %V", log->data); }