diff options
| author | Steven Luo <steven+qemu@steven676.net> | 2016-04-06 22:04:32 -0700 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2016-04-07 10:27:42 +0200 |
| commit | bfb1ac14029ee72b19296109fba880c0551755d5 (patch) | |
| tree | 270d62cb3221dc7f5353f8e7d5198ec1d98fb295 | |
| parent | b5ab677189b93efa4eaa921f42b21dc008247184 (diff) | |
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 <steven+qemu@steven676.net>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
| -rw-r--r-- | slirp/slirp.c | 12 | ||||
| -rw-r--r-- | slirp/socket.c | 17 | ||||
| -rw-r--r-- | slirp/socket.h | 2 |
3 files changed, 23 insertions, 8 deletions
diff --git a/slirp/slirp.c b/slirp/slirp.c index fef526c5ad..9f4bea3d3b 100644 --- a/slirp/slirp.c +++ b/slirp/slirp.c @@ -534,7 +534,12 @@ void slirp_pollfds_poll(GArray *pollfds, int select_error) * test for G_IO_IN below if this succeeds */ if (revents & G_IO_PRI) { - sorecvoob(so); + ret = sorecvoob(so); + if (ret < 0) { + /* Socket error might have resulted in the socket being + * removed, do not try to do anything more with it. */ + continue; + } } /* * Check sockets for reading @@ -553,6 +558,11 @@ void slirp_pollfds_poll(GArray *pollfds, int select_error) if (ret > 0) { tcp_output(sototcpcb(so)); } + if (ret < 0) { + /* Socket error might have resulted in the socket being + * removed, do not try to do anything more with it. */ + continue; + } } /* 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; } /* diff --git a/slirp/socket.h b/slirp/socket.h index e9c9b053dc..7dca506973 100644 --- a/slirp/socket.h +++ b/slirp/socket.h @@ -127,7 +127,7 @@ struct socket *solookup(struct socket **, struct socket *, struct socket *socreate(Slirp *); void sofree(struct socket *); int soread(struct socket *); -void sorecvoob(struct socket *); +int sorecvoob(struct socket *); int sosendoob(struct socket *); int sowrite(struct socket *); void sorecvfrom(struct socket *); |