gnu: QEMU: Fix CVE-2018-16872 and CVE-2019-6778.

* gnu/packages/patches/qemu-CVE-2018-16872.patch,
gnu/packages/patches/qemu-CVE-2019-6778.patch: New files.
* gnu/local.mk (dist_patch_DATA): Add them.
* gnu/packages/virtualization.scm (qemu)[source]: Use them.

gnu/local.mk

@@ -1186,6 +1186,8 @@ dist_patch_DATA =						\
   %D%/packages/patches/python-unittest2-remove-argparse.patch	\
   %D%/packages/patches/python-waitress-fix-tests.patch		\
   %D%/packages/patches/qemu-glibc-2.27.patch 			\
+  %D%/packages/patches/qemu-CVE-2018-16872.patch 		\
+  %D%/packages/patches/qemu-CVE-2019-6778.patch 		\
   %D%/packages/patches/qt4-ldflags.patch			\
   %D%/packages/patches/qtbase-use-TZDIR.patch			\
   %D%/packages/patches/qtscript-disable-tests.patch		\

gnu/packages/patches/qemu-CVE-2018-16872.patch

@@ -0,0 +1,88 @@
+Fixes CVE-2018-16872:
+
+https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-16872
+
+Patch copied from upstream source repository:
+
+https://git.qemu.org/?p=qemu.git;a=commitdiff;h=bab9df35ce73d1c8e19a37e2737717ea1c984dc1
+
+From bab9df35ce73d1c8e19a37e2737717ea1c984dc1 Mon Sep 17 00:00:00 2001
+From: Gerd Hoffmann <kraxel@redhat.com>
+Date: Thu, 13 Dec 2018 13:25:11 +0100
+Subject: [PATCH] usb-mtp: use O_NOFOLLOW and O_CLOEXEC.
+
+Open files and directories with O_NOFOLLOW to avoid symlinks attacks.
+While being at it also add O_CLOEXEC.
+
+usb-mtp only handles regular files and directories and ignores
+everything else, so users should not see a difference.
+
+Because qemu ignores symlinks, carrying out a successful symlink attack
+requires swapping an existing file or directory below rootdir for a
+symlink and winning the race against the inotify notification to qemu.
+
+Fixes: CVE-2018-16872
+Cc: Prasad J Pandit <ppandit@redhat.com>
+Cc: Bandan Das <bsd@redhat.com>
+Reported-by: Michael Hanselmann <public@hansmi.ch>
+Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
+Reviewed-by: Michael Hanselmann <public@hansmi.ch>
+Message-id: 20181213122511.13853-1-kraxel@redhat.com
+---
+ hw/usb/dev-mtp.c | 13 +++++++++----
+ 1 file changed, 9 insertions(+), 4 deletions(-)
+
+diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c
+index 100b7171f4..36c43b8c20 100644
+--- a/hw/usb/dev-mtp.c
++++ b/hw/usb/dev-mtp.c
+@@ -653,13 +653,18 @@ static void usb_mtp_object_readdir(MTPState *s, MTPObject *o)
+ {
+     struct dirent *entry;
+     DIR *dir;
++    int fd;
+ 
+     if (o->have_children) {
+         return;
+     }
+     o->have_children = true;
+ 
+-    dir = opendir(o->path);
++    fd = open(o->path, O_DIRECTORY | O_CLOEXEC | O_NOFOLLOW);
++    if (fd < 0) {
++        return;
++    }
++    dir = fdopendir(fd);
+     if (!dir) {
+         return;
+     }
+@@ -1007,7 +1012,7 @@ static MTPData *usb_mtp_get_object(MTPState *s, MTPControl *c,
+ 
+     trace_usb_mtp_op_get_object(s->dev.addr, o->handle, o->path);
+ 
+-    d->fd = open(o->path, O_RDONLY);
++    d->fd = open(o->path, O_RDONLY | O_CLOEXEC | O_NOFOLLOW);
+     if (d->fd == -1) {
+         usb_mtp_data_free(d);
+         return NULL;
+@@ -1031,7 +1036,7 @@ static MTPData *usb_mtp_get_partial_object(MTPState *s, MTPControl *c,
+                                         c->argv[1], c->argv[2]);
+ 
+     d = usb_mtp_data_alloc(c);
+-    d->fd = open(o->path, O_RDONLY);
++    d->fd = open(o->path, O_RDONLY | O_CLOEXEC | O_NOFOLLOW);
+     if (d->fd == -1) {
+         usb_mtp_data_free(d);
+         return NULL;
+@@ -1658,7 +1663,7 @@ static void usb_mtp_write_data(MTPState *s)
+                                  0, 0, 0, 0);
+             goto done;
+         }
+-        d->fd = open(path, O_CREAT | O_WRONLY, mask);
++        d->fd = open(path, O_CREAT | O_WRONLY | O_CLOEXEC | O_NOFOLLOW, mask);
+         if (d->fd == -1) {
+             usb_mtp_queue_result(s, RES_STORE_FULL, d->trans,
+                                  0, 0, 0, 0);
+-- 
+2.20.1
+

gnu/packages/patches/qemu-CVE-2019-6778.patch

@@ -0,0 +1,43 @@
+Fixes CVE-2019-6778:
+
+https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-6778
+
+Patch copied from upstream source repository:
+
+https://git.qemu.org/?p=qemu.git;a=commitdiff;h=a7104eda7dab99d0cdbd3595c211864cba415905
+
+From a7104eda7dab99d0cdbd3595c211864cba415905 Mon Sep 17 00:00:00 2001
+From: Prasad J Pandit <pjp@fedoraproject.org>
+Date: Sun, 13 Jan 2019 23:29:48 +0530
+Subject: [PATCH] slirp: check data length while emulating ident function
+
+While emulating identification protocol, tcp_emu() does not check
+available space in the 'sc_rcv->sb_data' buffer. It could lead to
+heap buffer overflow issue. Add check to avoid it.
+
+Reported-by: Kira <864786842@qq.com>
+Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
+Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
+---
+ slirp/tcp_subr.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/slirp/tcp_subr.c b/slirp/tcp_subr.c
+index 4a9a5b5edc..23a841f26e 100644
+--- a/slirp/tcp_subr.c
++++ b/slirp/tcp_subr.c
+@@ -634,6 +634,11 @@ tcp_emu(struct socket *so, struct mbuf *m)
+ 			socklen_t addrlen = sizeof(struct sockaddr_in);
+ 			struct sbuf *so_rcv = &so->so_rcv;
+ 
++			if (m->m_len > so_rcv->sb_datalen
++					- (so_rcv->sb_wptr - so_rcv->sb_data)) {
++			    return 1;
++			}
++
+ 			memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
+ 			so_rcv->sb_wptr += m->m_len;
+ 			so_rcv->sb_rptr += m->m_len;
+-- 
+2.20.1
+

gnu/packages/virtualization.scm

@@ -110,6 +110,8 @@ (define-public qemu
              (method url-fetch)
              (uri (string-append "https://download.qemu.org/qemu-"
                                  version ".tar.xz"))
+             (patches (search-patches "qemu-CVE-2018-16872.patch"
+                                      "qemu-CVE-2019-6778.patch"))
              (sha256
               (base32
                "1z5bd5nfyjvhfi1s95labc82y4hjdjjkdabw931362ls0zghh1ba"))))