From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35615) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gK33L-0004DP-PK for qemu-devel@nongnu.org; Tue, 06 Nov 2018 10:14:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gK33E-0004mJ-7U for qemu-devel@nongnu.org; Tue, 06 Nov 2018 10:14:03 -0500 Received: from orth.archaic.org.uk ([2001:8b0:1d0::2]:52316) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gK33D-0004AK-Sy for qemu-devel@nongnu.org; Tue, 06 Nov 2018 10:13:56 -0500 From: Peter Maydell Date: Tue, 6 Nov 2018 15:13:20 +0000 Message-Id: <20181106151323.16154-2-peter.maydell@linaro.org> In-Reply-To: <20181106151323.16154-1-peter.maydell@linaro.org> References: <20181106151323.16154-1-peter.maydell@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PATCH for-3.1 1/4] slirp: Don't pass possibly -1 fd to send() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: patches@linaro.org, Samuel Thibault , Jan Kiszka Coverity complains (CID 1005726) that we might pass -1 as the fd argument to send() in slirp_send(), because we previously checked for "so->s == -1 && so->extra". The case of "so->s == -1 but so->extra NULL" should not in theory happen, but it is hard to guarantee because various places in the code do so->s = qemu_socket(...) and so will end up with so->s == -1 on failure, and not all the paths which call that always throw away the socket in that case (eg tcp_fconnect()). So just check specifically for the condition and fail slirp_send(). Signed-off-by: Peter Maydell --- This is to some extent just placating Coverity. --- slirp/slirp.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/slirp/slirp.c b/slirp/slirp.c index 51de41fc021..3c3c03b22f7 100644 --- a/slirp/slirp.c +++ b/slirp/slirp.c @@ -1091,6 +1091,17 @@ ssize_t slirp_send(struct socket *so, const void *buf, size_t len, int flags) return len; } + if (so->s == -1) { + /* + * This should in theory not happen but it is hard to be + * sure because some code paths will end up with so->s == -1 + * on a failure but don't dispose of the struct socket. + * Check specifically, so we don't pass -1 to send(). + */ + errno = EBADF; + return -1; + } + return send(so->s, buf, len, flags); } -- 2.19.1