Merge remote-tracking branch 'remotes/philmd-gitlab/tags/sdcard-CVE-2020-13253-pull-request' into staging

Fix CVE-2020-13253

By using invalidated address, guest can do out-of-bounds accesses.
These patches fix the issue by only allowing SD card image sizes
power of 2, and not switching to SEND_DATA state when the address
is invalid (out of range).

This issue was found using QEMU fuzzing mode (using --enable-fuzzing,
see docs/devel/fuzzing.txt) and reported by Alexander Bulekov.

Reproducer:
  https://bugs.launchpad.net/qemu/+bug/1880822/comments/1

CI jobs results:
. https://cirrus-ci.com/build/5157142548185088
. https://gitlab.com/philmd/qemu/-/pipelines/166381731
. https://travis-ci.org/github/philmd/qemu/builds/707956535

# gpg: Signature made Tue 14 Jul 2020 14:54:44 BST
# gpg:                using RSA key FAABE75E12917221DCFD6BB2E3E32C2CDEADC0DE
# gpg: Good signature from "Philippe Mathieu-Daudé (F4BUG) <f4bug@amsat.org>" [full]
# Primary key fingerprint: FAAB E75E 1291 7221 DCFD  6BB2 E3E3 2C2C DEAD C0DE

* remotes/philmd-gitlab/tags/sdcard-CVE-2020-13253-pull-request:
  hw/sd/sdcard: Do not switch to ReceivingData if address is invalid
  hw/sd/sdcard: Update coding style to make checkpatch.pl happy
  hw/sd/sdcard: Do not allow invalid SD card sizes
  hw/sd/sdcard: Simplify realize() a bit
  hw/sd/sdcard: Restrict Class 6 commands to SCSD cards
  tests/acceptance/boot_linux: Expand SD card image to power of 2
  tests/acceptance/boot_linux: Tag tests using a SD card with 'device:sd'
  docs/orangepi: Add instructions for resizing SD image to power of two
  MAINTAINERS: Cc qemu-block mailing list

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 25 insertions, 9 deletions

diff --git a/tests/acceptance/boot_linux_console.py b/tests/acceptance/boot_linux_console.py
index 3d02519660..67c3b2f3d1 100644
--- a/tests/acceptance/boot_linux_console.py
+++ b/tests/acceptance/boot_linux_console.py
@@ -28,6 +28,22 @@ try:
 except CmdNotFoundError:
     P7ZIP_AVAILABLE = False
 
+"""
+Round up to next power of 2
+"""
+def pow2ceil(x):
+    return 1 if x == 0 else 2**(x - 1).bit_length()
+
+"""
+Expand file size to next power of 2
+"""
+def image_pow2ceil_expand(path):
+        size = os.path.getsize(path)
+        size_aligned = pow2ceil(size)
+        if size != size_aligned:
+            with open(path, 'ab+') as fd:
+                fd.truncate(size_aligned)
+
 class LinuxKernelTest(Test):
     KERNEL_COMMON_COMMAND_LINE = 'printk.time=0 '
 
@@ -620,6 +636,7 @@ class BootLinuxConsole(LinuxKernelTest):
         """
         :avocado: tags=arch:arm
         :avocado: tags=machine:orangepi-pc
+        :avocado: tags=device:sd
         """
         deb_url = ('https://apt.armbian.com/pool/main/l/'
                    'linux-4.20.7-sunxi/linux-image-dev-sunxi_5.75_armhf.deb')
@@ -635,6 +652,7 @@ class BootLinuxConsole(LinuxKernelTest):
         rootfs_path_xz = self.fetch_asset(rootfs_url, asset_hash=rootfs_hash)
         rootfs_path = os.path.join(self.workdir, 'rootfs.cpio')
         archive.lzma_uncompress(rootfs_path_xz, rootfs_path)
+        image_pow2ceil_expand(rootfs_path)
 
         self.vm.set_console()
         kernel_command_line = (self.KERNEL_COMMON_COMMAND_LINE +
@@ -669,9 +687,10 @@ class BootLinuxConsole(LinuxKernelTest):
         """
         :avocado: tags=arch:arm
         :avocado: tags=machine:orangepi-pc
+        :avocado: tags=device:sd
         """
 
-        # This test download a 196MB compressed image and expand it to 932MB...
+        # This test download a 196MB compressed image and expand it to 1GB
         image_url = ('https://dl.armbian.com/orangepipc/archive/'
                      'Armbian_19.11.3_Orangepipc_bionic_current_5.3.9.7z')
         image_hash = '196a8ffb72b0123d92cea4a070894813d305c71e'
@@ -679,6 +698,7 @@ class BootLinuxConsole(LinuxKernelTest):
         image_name = 'Armbian_19.11.3_Orangepipc_bionic_current_5.3.9.img'
         image_path = os.path.join(self.workdir, image_name)
         process.run("7z e -o%s %s" % (self.workdir, image_path_7z))
+        image_pow2ceil_expand(image_path)
 
         self.vm.set_console()
         self.vm.add_args('-drive', 'file=' + image_path + ',if=sd,format=raw',
@@ -710,8 +730,9 @@ class BootLinuxConsole(LinuxKernelTest):
         """
         :avocado: tags=arch:arm
         :avocado: tags=machine:orangepi-pc
+        :avocado: tags=device:sd
         """
-        # This test download a 304MB compressed image and expand it to 1.3GB...
+        # This test download a 304MB compressed image and expand it to 2GB
         deb_url = ('http://snapshot.debian.org/archive/debian/'
                    '20200108T145233Z/pool/main/u/u-boot/'
                    'u-boot-sunxi_2020.01%2Bdfsg-1_armhf.deb')
@@ -728,8 +749,9 @@ class BootLinuxConsole(LinuxKernelTest):
         image_hash = '2babb29d36d8360adcb39c09e31060945259917a'
         image_path_gz = self.fetch_asset(image_url, asset_hash=image_hash)
         image_path = os.path.join(self.workdir, 'armv7.img')
-        image_drive_args = 'if=sd,format=raw,snapshot=on,file=' + image_path
         archive.gzip_uncompress(image_path_gz, image_path)
+        image_pow2ceil_expand(image_path)
+        image_drive_args = 'if=sd,format=raw,snapshot=on,file=' + image_path
 
         # dd if=u-boot-sunxi-with-spl.bin of=armv7.img bs=1K seek=8 conv=notrunc
         with open(uboot_path, 'rb') as f_in:
@@ -737,12 +759,6 @@ class BootLinuxConsole(LinuxKernelTest):
                 f_out.seek(8 * 1024)
                 shutil.copyfileobj(f_in, f_out)
 
-                # Extend image, to avoid that NetBSD thinks the partition
-                # inside the image is larger than device size itself
-                f_out.seek(0, 2)
-                f_out.seek(64 * 1024 * 1024, 1)
-                f_out.write(bytearray([0x00]))
-
         self.vm.set_console()
         self.vm.add_args('-nic', 'user',
                          '-drive', image_drive_args,