From: William Bowling Date: Fri, 1 Mar 2019 21:45:56 +0000 Subject: slirp: check sscanf result when emulating ident MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When emulating ident in tcp_emu, if the strchr checks passed but the sscanf check failed, two uninitialized variables would be copied and sent in the reply, so move this code inside the if(sscanf()) clause. Signed-off-by: William Bowling Cc: qemu-stable@nongnu.org Cc: secalert@redhat.com Message-Id: <1551476756-25749-1-git-send-email-will@wbowling.info> Signed-off-by: Samuel Thibault Reviewed-by: Philippe Mathieu-Daudé (cherry picked from commit d3222975c7d6cda9e25809dea05241188457b113) [BR: BSC#1129622 CVE-2019-9824 To pass our checkpatch check, I changed the patch to use spaces, not tabs, as in the initially proposed] Signed-off-by: Bruce Rogers --- slirp/tcp_subr.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/slirp/tcp_subr.c b/slirp/tcp_subr.c index 7a23ce738c..a6fd8626a8 100644 --- a/slirp/tcp_subr.c +++ b/slirp/tcp_subr.c @@ -661,12 +661,12 @@ tcp_emu(struct socket *so, struct mbuf *m) break; } } + so_rcv->sb_cc = snprintf(so_rcv->sb_data, + so_rcv->sb_datalen, + "%d,%d\r\n", n1, n2); + so_rcv->sb_rptr = so_rcv->sb_data; + so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc; } - so_rcv->sb_cc = snprintf(so_rcv->sb_data, - so_rcv->sb_datalen, - "%d,%d\r\n", n1, n2); - so_rcv->sb_rptr = so_rcv->sb_data; - so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc; } m_free(m); return 0;