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changeset 359:a3e674fade6c

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From Jeffrey Morlan: pst_parse_block misreads Table Contexts (aka "type 2") with a multi-block Row Matrix ("ind2"). Rows are never split between blocks - every block except the last has padding at the end which should be ignored. I've only seen this affect the recipients table, but presumably it could affect attachments too. This was causing out-of-bounds memory ranges to be returned from pst_getBlockOffset and later access; patch fixes both the table reading issue and adds a missing bounds check to pst_getBlockOffset (so as not to risk a segfault if the PST is corrupted).
author Carl Byington <carl@five-ten-sg.com>
date Wed, 06 Jul 2016 10:20:12 -0700
parents 6abc3054cba2
children 26c48ea9d896
files src/libpst.c
diffstat 1 files changed, 11 insertions(+), 2 deletions(-) [+]
line wrap: on
line diff
--- a/src/libpst.c	Wed Jul 06 10:19:01 2016 -0700
+++ b/src/libpst.c	Wed Jul 06 10:20:12 2016 -0700
@@ -1405,6 +1405,8 @@
     char*    to_ptr;
     char*    ind2_end = NULL;
     char*    ind2_ptr = NULL;
+    char*    ind2_block_start = NULL;
+    size_t   ind2_max_block_size = pf->do_read64 ? 0x1FF0 : 0x1FF4;
     pst_x_attrib_ll *mapptr;
     pst_block_hdr    block_hdr;
     pst_table3_rec   table3_rec;  //for type 3 (0x0101) blocks
@@ -1601,6 +1603,7 @@
                 return NULL;
             }
             ind2_ptr = block_offset6.from;
+            ind2_block_start = ind2_ptr;
             ind2_end = block_offset6.to;
         }
         else {
@@ -1832,6 +1835,12 @@
         }
         DEBUG_INFO(("increasing ind2_ptr by %i [%#x] bytes. Was %#x, Now %#x\n", rec_size, rec_size, ind2_ptr, ind2_ptr+rec_size));
         ind2_ptr += rec_size;
+        // ind2 rows do not get split between blocks. See PST spec, 2.3.4.4 "Row Matrix".
+        if (ind2_ptr + rec_size > ind2_block_start + ind2_max_block_size) {
+            ind2_block_start += ind2_max_block_size;
+            DEBUG_INFO(("advancing ind2_ptr to next block. Was %#x, Now %#x\n", ind2_ptr, ind2_block_start));
+            ind2_ptr = ind2_block_start;
+        }
     }
     freeall(&subblocks, &block_offset1, &block_offset2, &block_offset3, &block_offset4, &block_offset5, &block_offset6, &block_offset7);
     DEBUG_RET();
@@ -3601,8 +3610,8 @@
     LE16_CPU(p->from);
     LE16_CPU(p->to);
     DEBUG_WARN(("get block offset finds from=%i(%#x), to=%i(%#x)\n", p->from, p->from, p->to, p->to));
-    if (p->from > p->to) {
-        DEBUG_WARN(("get block offset from > to\n"));
+    if (p->from > p->to || p->to > read_size) {
+        DEBUG_WARN(("get block offset bad range\n"));
         DEBUG_RET();
         return 0;
     }