Check for overflow when calculating on-disk attribute data size (HDFG…

…roup#2459)

* Remove duplicate code

Signed-off-by: Egbert Eich <eich@suse.com>

* Add test case for CVE-2021-37501

Bogus sizes in this test case causes the on-disk data size
calculation in H5O__attr_decode() to overflow so that the
calculated size becomes 0. This causes the read to overflow
and h5dump to segfault.
This test case was crafted, the test file was not directly
generated by HDF5.
Test case from:
https://github.com/ST4RF4LL/Something_Found/blob/main/HDF5_v1.13.0_h5dump_heap_overflow.md

release_docs/RELEASE.txt

@@ -198,6 +198,19 @@ Bug Fixes since HDF5-1.10.9 release
 ===================================
     Library
     -------
+    - Fix CVE-2021-37501 / GHSA-rfgw-5vq3-wrjf
+
+      Check for overflow when calculating on-disk attribute data size.
+
+      A bogus hdf5 file may contain dataspace messages with sizes
+      which lead to the on-disk data sizes to exceed what is addressable.
+      When calculating the size, make sure, the multiplication does not
+      overflow.
+      The test case was crafted in a way that the overflow caused the
+      size to be 0.
+
+      (EFE - 2023/02/11 GH-2458)
+
     - Fixed an issue with variable length attributes
 
       Previously, if a variable length attribute was held open while its file

src/H5Oattr.c

@@ -221,10 +221,6 @@ H5O_attr_decode(H5F_t *f, H5O_t *open_oh, unsigned H5_ATTR_UNUSED mesg_flags, un
     else
         p += attr->shared->ds_size;
 
-    /* Get the datatype's size */
-    if (0 == (dt_size = H5T_get_size(attr->shared->dt)))
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, NULL, "unable to get datatype size")
-
     /* Get the datatype & dataspace sizes */
     if (0 == (dt_size = H5T_get_size(attr->shared->dt)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, NULL, "unable to get datatype size")
@@ -234,6 +230,9 @@ H5O_attr_decode(H5F_t *f, H5O_t *open_oh, unsigned H5_ATTR_UNUSED mesg_flags, un
 
     /* Compute the size of the data */
     H5_CHECKED_ASSIGN(attr->shared->data_size, size_t, ds_size * (hsize_t)dt_size, hsize_t);
+    /* Check if multiplication has overflown */
+    if ((attr->shared->data_size / dt_size) != ds_size)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_OVERFLOW, NULL, "data size exceeds addressable range")
 
     /* Go get the data */
     if (attr->shared->data_size) {

tools/test/h5dump/CMakeTests.cmake

@@ -327,6 +327,7 @@
       ${HDF5_TOOLS_DIR}/testfiles/tCVE_2018_11206_fill_old.h5
       ${HDF5_TOOLS_DIR}/testfiles/tCVE_2018_11206_fill_new.h5
       ${HDF5_TOOLS_DIR}/testfiles/zerodim.h5
+      ${HDF5_TOOLS_DIR}/testfiles/tCVE-2021-37501_attr_decode.h5
   )
   set (HDF5_ERROR_REFERENCE_TEST_FILES
       ${PROJECT_SOURCE_DIR}/errfiles/filter_fail.err
@@ -1145,6 +1146,9 @@
   # test to verify HDFFV-10480: out of bounds read in H5O_fill_new[old]_decode
   ADD_H5_TEST (tCVE_2018_11206_fill_old 1 tCVE_2018_11206_fill_old.h5)
   ADD_H5_TEST (tCVE_2018_11206_fill_new 1 tCVE_2018_11206_fill_new.h5)
+  # test to verify fix for CVE-2021-37501: multiplication overflow in H5O__attr_decode()
+  # https://github.com/ST4RF4LL/Something_Found/blob/main/HDF5_v1.13.0_h5dump_heap_overflow.assets/poc
+  ADD_H5_TEST (tCVE-2021-37501_attr_decode 1 tCVE-2021-37501_attr_decode.h5)
 
 ##############################################################################
 ###    P L U G I N  T E S T S

tools/test/h5dump/testh5dump.sh.in

@@ -180,6 +180,7 @@ $SRC_H5DUMP_TESTFILES/tvlstr.h5
 $SRC_H5DUMP_TESTFILES/tvms.h5
 $SRC_H5DUMP_TESTFILES/tCVE_2018_11206_fill_old.h5
 $SRC_H5DUMP_TESTFILES/tCVE_2018_11206_fill_new.h5
+$SRC_H5DUMP_TESTFILES/tCVE-2021-37501_attr_decode.h5
 "
 
 LIST_OTHER_TEST_FILES="
@@ -1475,6 +1476,10 @@ TOOLTEST3 non_existing.ddl --enable-error-stack tgroup.h5 non_existing.h5
 TOOLTEST_FAIL tCVE_2018_11206_fill_old.h5
 TOOLTEST_FAIL tCVE_2018_11206_fill_new.h5
 
+# test to verify fix for CVE-2021-37501: multiplication overflow in H5O__attr_decode()
+# https://github.com/ST4RF4LL/Something_Found/blob/main/HDF5_v1.13.0_h5dump_heap_overflow.assets/poc
+TOOLTEST_FAIL tCVE-2021-37501_attr_decode.h5
+
 # Clean up temporary files/directories
 CLEAN_TESTFILES_AND_TESTDIR