From 26a57486f013abff616be8345e542c15419f0759 Mon Sep 17 00:00:00 2001 From: Roman Arutyunyan Date: Fri, 1 Jun 2018 16:53:02 +0300 Subject: [PATCH] Events: fixed handling zero-length client address. On Linux recvmsg() syscall may return a zero-length client address when receiving a datagram from an unbound unix datagram socket. It is usually assumed that socket address has at least the sa_family member. Zero-length socket address caused buffer over-read in functions which receive socket address, for example ngx_sock_ntop(). Typically the over-read resulted in unexpected socket family followed by session close. Now a fake socket address is allocated instead of a zero-length client address. --- src/event/ngx_event_accept.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/event/ngx_event_accept.c b/src/event/ngx_event_accept.c index 775637090..7e9f742a0 100644 --- a/src/event/ngx_event_accept.c +++ b/src/event/ngx_event_accept.c @@ -448,6 +448,18 @@ ngx_event_recvmsg(ngx_event_t *ev) c->socklen = sizeof(ngx_sockaddr_t); } + if (c->socklen == 0) { + + /* + * on Linux recvmsg() returns zero msg_namelen + * when receiving packets from unbound AF_UNIX sockets + */ + + c->socklen = sizeof(struct sockaddr); + ngx_memzero(&sa, sizeof(struct sockaddr)); + sa.sockaddr.sa_family = ls->sockaddr->sa_family; + } + #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_active, 1); #endif