osmocom
/
wireshark
11
0
Fork 1
Code Issues Pull Requests Projects Releases Wiki Activity

proto: fix proto_item_add_bitmask_tree with zero length 

packet-frame.c calls proto_item_add_bitmask_tree with a zero length, be
sure not to trigger undefined behavior (right shift by 64). Observed
with the capture from Bug 15247.

Change-Id: I5b5b7f920a37365295603be7b915f51b39d99faf
Fixes: v2.1.0rc0-1776-gb9fb2ceb88 ("Add heuristic dissectors for the variable part of COTP CR and CC PDUs.")
Reviewed-on: https://code.wireshark.org/review/34108
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Tested-by: Petri Dish Buildbot
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
This commit is contained in:
Peter Wu 2019-07-28 17:58:53 +01:00
parent 53ecc16079
commit 77b6160696
1 changed files with 9 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
epan/proto.c
View File

@ -11027,8 +11027,7 @@ proto_item_add_bitmask_tree(proto_item *item, tvbuff_t *tvb, const int offset,
gboolean use_parent_tree,
proto_tree* tree, guint64 value)
{
guint bitshift;
guint64 available_bits = 0;
guint64 available_bits = G_MAXUINT64;
guint64 tmpval;
header_field_info *hf;
guint32 integer32;
@ -11036,8 +11035,14 @@ proto_item_add_bitmask_tree(proto_item *item, tvbuff_t *tvb, const int offset,
if (len < 0 || len > 8)
g_assert_not_reached();
bitshift = (8 - (guint)len)*8;
available_bits = G_GUINT64_CONSTANT(0xFFFFFFFFFFFFFFFF) >> bitshift;
/**
* packet-frame.c uses len=0 since the value is taken from the packet
* metadata, not the packet bytes. In that case, assume that all bits
* in the provided value are valid.
*/
if (len > 0) {
available_bits >>= (8 - (guint)len)*8;
}
if (use_parent_tree == FALSE)
tree = proto_item_add_subtree(item, ett);