main/xen: security fixes (CVE-2013-1917,CVE-2013-1919,CVE-2013-1920,CVE-2013-1922)

CVE-2013-1917 / XSA-44
CVE-2013-1919 / XSA-46
CVE-2013-1920 / XSA-47
CVE-2013-1922 / XSA-48

Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>

1 files changed, 114 insertions, 0 deletions

diff --git a/main/xen/xsa48-4.2.patch b/main/xen/xsa48-4.2.patch
new file mode 100644
index 0000000000..998dbcb1d5
--- /dev/null
+++ b/main/xen/xsa48-4.2.patch
@@ -0,0 +1,114 @@
+Add -f FMT  / --format FMT arg to qemu-nbd
+
+From: "Daniel P. Berrange" <berrange@redhat.com>
+
+Currently the qemu-nbd program will auto-detect the format of
+any disk it is given. This behaviour is known to be insecure.
+For example, if qemu-nbd initially exposes a 'raw' file to an
+unprivileged app, and that app runs
+
+   'qemu-img create -f qcow2 -o backing_file=/etc/shadow /dev/nbd0'
+
+then the next time the app is started, the qemu-nbd will now
+detect it as a 'qcow2' file and expose /etc/shadow to the
+unprivileged app.
+
+The only way to avoid this is to explicitly tell qemu-nbd what
+disk format to use on the command line, completely disabling
+auto-detection. This patch adds a '-f' / '--format' arg for
+this purpose, mirroring what is already available via qemu-img
+and qemu commands.
+
+  qemu-nbd --format raw -p 9000 evil.img
+
+will now always use raw, regardless of what format 'evil.img'
+looks like it contains
+
+Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
+[Use errx, not err. - Paolo]
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
+
+[ This is a security issue, CVE-2013-1922 / XSA-48. ]
+
+diff --git a/qemu-nbd.c b/qemu-nbd.c
+index 291cba2..8fbe2cf 100644
+--- a/tools/qemu-xen/qemu-nbd.c
++++ b/tools/qemu-xen/qemu-nbd.c
+@@ -247,6 +247,7 @@ out:
+ int main(int argc, char **argv)
+ {
+     BlockDriverState *bs;
++    BlockDriver *drv;
+     off_t dev_offset = 0;
+     off_t offset = 0;
+     uint32_t nbdflags = 0;
+@@ -256,7 +257,7 @@ int main(int argc, char **argv)
+     struct sockaddr_in addr;
+     socklen_t addr_len = sizeof(addr);
+     off_t fd_size;
+-    const char *sopt = "hVb:o:p:rsnP:c:dvk:e:t";
++    const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:t";
+     struct option lopt[] = {
+         { "help", 0, NULL, 'h' },
+         { "version", 0, NULL, 'V' },
+@@ -271,6 +272,7 @@ int main(int argc, char **argv)
+         { "snapshot", 0, NULL, 's' },
+         { "nocache", 0, NULL, 'n' },
+         { "shared", 1, NULL, 'e' },
++        { "format", 1, NULL, 'f' },
+         { "persistent", 0, NULL, 't' },
+         { "verbose", 0, NULL, 'v' },
+         { NULL, 0, NULL, 0 }
+@@ -292,6 +294,7 @@ int main(int argc, char **argv)
+     int max_fd;
+     int persistent = 0;
+     pthread_t client_thread;
++    const char *fmt = NULL;
+ 
+     /* The client thread uses SIGTERM to interrupt the server.  A signal
+      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
+@@ -368,6 +371,9 @@ int main(int argc, char **argv)
+                 errx(EXIT_FAILURE, "Shared device number must be greater than 0\n");
+             }
+             break;
++        case 'f':
++            fmt = optarg;
++            break;
+ 	case 't':
+ 	    persistent = 1;
+ 	    break;
+@@ -478,9 +484,19 @@ int main(int argc, char **argv)
+     bdrv_init();
+     atexit(bdrv_close_all);
+ 
++    if (fmt) {
++        drv = bdrv_find_format(fmt);
++        if (!drv) {
++            errx(EXIT_FAILURE, "Unknown file format '%s'", fmt);
++        }
++    } else {
++        drv = NULL;
++    }
++
+     bs = bdrv_new("hda");
+     srcpath = argv[optind];
+-    if ((ret = bdrv_open(bs, srcpath, flags, NULL)) < 0) {
++    ret = bdrv_open(bs, srcpath, flags, drv);
++    if (ret < 0) {
+         errno = -ret;
+         err(EXIT_FAILURE, "Failed to bdrv_open '%s'", argv[optind]);
+     }
+diff --git a/qemu-nbd.texi b/qemu-nbd.texi
+index 44996cc..f56c68e 100644
+--- a/tools/qemu-xen/qemu-nbd.texi
++++ b/tools/qemu-xen/qemu-nbd.texi
+@@ -36,6 +36,8 @@ Export Qemu disk image using NBD protocol.
+   disconnect the specified device
+ @item -e, --shared=@var{num}
+   device can be shared by @var{num} clients (default @samp{1})
++@item -f, --format=@var{fmt}
++  force block driver for format @var{fmt} instead of auto-detecting
+ @item -t, --persistent
+   don't exit on the last connection
+ @item -v, --verbose