libavb: Update libavb to current AOSP master

Update libavb to commit 5fbb42a189aa in AOSP/master, because new version
has support for super partition [1], which we need for implementing
Android dynamic partitions. All changes from previous patches for libavb
in U-Boot are accounted for in this commit:
  - commit ecc6f6bea6a2 ("libavb: Handle wrong hashtree_error_mode in
                          avb_append_options()")
  - commit 897a1d947e7e ("libavb: Update SPDX tag style")
  - commit d8f9d2af96b3 ("avb2.0: add Android Verified Boot 2.0 library")

Tested on X15:

    ## Android Verified Boot 2.0 version 1.1.0
    read_is_device_unlocked not supported yet
    read_rollback_index not supported yet
    read_is_device_unlocked not supported yet
    Verification passed successfully
    AVB verification OK.

Unit test passes:

    $ ./test/py/test.py --bd sandbox --build -k test_avb

      test/py/tests/test_android/test_avb.py ss..s.

[1] https://android.googlesource.com/platform/external/avb/+/49936b4c0109411fdd38bd4ba3a32a01c40439a9

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Eugeniu Rosca <rosca.eugeniu@gmail.com>
Acked-by: Igor Opaniuk <igor.opaniuk@gmail.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/lib/libavb/avb_descriptor.c b/lib/libavb/avb_descriptor.c
index fb0b305f2c..9f03b9777a 100644
--- a/lib/libavb/avb_descriptor.c
+++ b/lib/libavb/avb_descriptor.c
@@ -72,7 +72,11 @@ bool avb_descriptor_foreach(const uint8_t* image_data,
     const AvbDescriptor* dh = (const AvbDescriptor*)p;
     avb_assert_aligned(dh);
     uint64_t nb_following = avb_be64toh(dh->num_bytes_following);
-    uint64_t nb_total = sizeof(AvbDescriptor) + nb_following;
+    uint64_t nb_total = 0;
+    if (!avb_safe_add(&nb_total, sizeof(AvbDescriptor), nb_following)) {
+      avb_error("Invalid descriptor length.\n");
+      goto out;
+    }
 
     if ((nb_total & 7) != 0) {
       avb_error("Invalid descriptor length.\n");
@@ -88,7 +92,10 @@ bool avb_descriptor_foreach(const uint8_t* image_data,
       goto out;
     }
 
-    p += nb_total;
+    if (!avb_safe_add_to((uint64_t*)(&p), nb_total)) {
+      avb_error("Invalid descriptor length.\n");
+      goto out;
+    }
   }
 
   ret = true;