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.

1 files changed, 88 insertions, 0 deletions

diff --git a/gnu/packages/patches/qemu-CVE-2018-16872.patch b/gnu/packages/patches/qemu-CVE-2018-16872.patch
new file mode 100644
index 0000000000..094e823ee4
--- /dev/null
+++ b/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
+