diff options
author | Darren Tucker <dtucker@zip.com.au> | 2010-01-08 17:08:00 +1100 |
---|---|---|
committer | Darren Tucker <dtucker@zip.com.au> | 2010-01-08 17:08:00 +1100 |
commit | 876045b0fb273ee11b02c535833b076c875253dc (patch) | |
tree | 372ba1e8310e20e1874a5aac76ed3a7194aec9cb /channels.c | |
parent | 6e7fe1c01b8a69099ffc42e653cc478509e84781 (diff) |
- markus@cvs.openbsd.org 2009/11/11 21:37:03
[channels.c channels.h]
fix race condition in x11/agent channel allocation: don't read after
the end of the select read/write fdset and make sure a reused FD
is not touched before the pre-handlers are called.
with and ok djm@
Diffstat (limited to 'channels.c')
-rw-r--r-- | channels.c | 26 |
1 files changed, 11 insertions, 15 deletions
@@ -1,4 +1,4 @@ -/* $OpenBSD: channels.c,v 1.298 2009/11/10 04:30:44 dtucker Exp $ */ +/* $OpenBSD: channels.c,v 1.299 2009/11/11 21:37:03 markus Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -331,6 +331,7 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd, c->output_filter = NULL; c->filter_ctx = NULL; c->filter_cleanup = NULL; + c->delayed = 1; /* prevent call to channel_post handler */ TAILQ_INIT(&c->status_confirms); debug("channel %d: new [%s]", found, remote_name); return c; @@ -1228,7 +1229,6 @@ channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset) int ret; have = buffer_len(&c->input); - c->delayed = 0; debug2("channel %d: pre_dynamic: have %d", c->self, have); /* buffer_dump(&c->input); */ /* check if the fixed size part of the packet is in buffer. */ @@ -1432,16 +1432,8 @@ channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset) if (c->path != NULL) nc->path = xstrdup(c->path); - if (nextstate == SSH_CHANNEL_DYNAMIC) { - /* - * do not call the channel_post handler until - * this flag has been reset by a pre-handler. - * otherwise the FD_ISSET calls might overflow - */ - nc->delayed = 1; - } else { + if (nextstate != SSH_CHANNEL_DYNAMIC) port_open_helper(nc, rtype); - } } } @@ -1786,8 +1778,6 @@ channel_check_window(Channel *c) static void channel_post_open(Channel *c, fd_set *readset, fd_set *writeset) { - if (c->delayed) - return; channel_handle_rfd(c, readset, writeset); channel_handle_wfd(c, readset, writeset); if (!compat20) @@ -1919,17 +1909,23 @@ static void channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset) { static int did_init = 0; - u_int i; + u_int i, oalloc; Channel *c; if (!did_init) { channel_handler_init(); did_init = 1; } - for (i = 0; i < channels_alloc; i++) { + for (i = 0, oalloc = channels_alloc; i < oalloc; i++) { c = channels[i]; if (c == NULL) continue; + if (c->delayed) { + if (ftab == channel_pre) + c->delayed = 0; + else + continue; + } if (ftab[c->type] != NULL) (*ftab[c->type])(c, readset, writeset); channel_garbage_collect(c); |