From bfb1ac14029ee72b19296109fba880c0551755d5 Mon Sep 17 00:00:00 2001 From: Steven Luo Date: Wed, 6 Apr 2016 22:04:32 -0700 Subject: slirp: avoid use-after-free in slirp_pollfds_poll() if soread() returns an error Samuel Thibault pointed out that it's possible that slirp_pollfds_poll() will try to use a socket even after soread() returns an error, resulting in an use-after-free if the socket was removed while handling the error. Avoid this by refusing to continue to work with the socket in this case. Signed-off-by: Steven Luo Signed-off-by: Samuel Thibault --- slirp/socket.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'slirp/socket.c') diff --git a/slirp/socket.c b/slirp/socket.c index b836c42b8e..7f022a6769 100644 --- a/slirp/socket.c +++ b/slirp/socket.c @@ -260,10 +260,11 @@ err: * so when OOB data arrives, we soread() it and everything * in the send buffer is sent as urgent data */ -void +int sorecvoob(struct socket *so) { struct tcpcb *tp = sototcpcb(so); + int ret; DEBUG_CALL("sorecvoob"); DEBUG_ARG("so = %p", so); @@ -276,11 +277,15 @@ sorecvoob(struct socket *so) * urgent data, or the read() doesn't return all the * urgent data. */ - soread(so); - tp->snd_up = tp->snd_una + so->so_snd.sb_cc; - tp->t_force = 1; - tcp_output(tp); - tp->t_force = 0; + ret = soread(so); + if (ret > 0) { + tp->snd_up = tp->snd_una + so->so_snd.sb_cc; + tp->t_force = 1; + tcp_output(tp); + tp->t_force = 0; + } + + return ret; } /* -- cgit v1.2.3