iconv: Accept redundant shift sequences in IBM1364 [BZ #26224]
Commit Message
From: Arjun Shankar <arjun@redhat.com>
The IBM1364, IBM1371, IBM1388, IBM1390 and IBM1399 character sets
share converter logic (iconvdata/ibm1364.c) which would reject
redundant shift sequences when processing input in these character
sets. This led to a hang in the iconv program (CVE-2020-27618).
This commit adjusts the converter to ignore redundant shift sequences
and adds test cases for iconv_prog hangs that would be triggered upon
their rejection. This brings the implementation in line with other
converters that also ignore redundant shift sequences (e.g. IBM930
etc., fixed in commit 692de4b3960d).
---
iconv/tst-iconv_prog.sh | 16 ++++++++++------
iconvdata/ibm1364.c | 14 ++------------
2 files changed, 12 insertions(+), 18 deletions(-)
Comments
* Arjun Shankar:
> From: Arjun Shankar <arjun@redhat.com>
>
> The IBM1364, IBM1371, IBM1388, IBM1390 and IBM1399 character sets
> share converter logic (iconvdata/ibm1364.c) which would reject
> redundant shift sequences when processing input in these character
> sets. This led to a hang in the iconv program (CVE-2020-27618).
>
> This commit adjusts the converter to ignore redundant shift sequences
> and adds test cases for iconv_prog hangs that would be triggered upon
> their rejection. This brings the implementation in line with other
> converters that also ignore redundant shift sequences (e.g. IBM930
> etc., fixed in commit 692de4b3960d).
Can you update the news file as well? Thanks.
Florian
@@ -102,12 +102,16 @@ hangarray=(
"\x00\x80;-c;IBM1161;UTF-8//TRANSLIT//IGNORE"
"\x00\xdb;-c;IBM1162;UTF-8//TRANSLIT//IGNORE"
"\x00\x70;-c;IBM12712;UTF-8//TRANSLIT//IGNORE"
-# These are known hangs that are yet to be fixed:
-# "\x00\x0f;-c;IBM1364;UTF-8"
-# "\x00\x0f;-c;IBM1371;UTF-8"
-# "\x00\x0f;-c;IBM1388;UTF-8"
-# "\x00\x0f;-c;IBM1390;UTF-8"
-# "\x00\x0f;-c;IBM1399;UTF-8"
+"\x00\x0f;-c;IBM1364;UTF-8"
+"\x0e\x0e;-c;IBM1364;UTF-8"
+"\x00\x0f;-c;IBM1371;UTF-8"
+"\x0e\x0e;-c;IBM1371;UTF-8"
+"\x00\x0f;-c;IBM1388;UTF-8"
+"\x0e\x0e;-c;IBM1388;UTF-8"
+"\x00\x0f;-c;IBM1390;UTF-8"
+"\x0e\x0e;-c;IBM1390;UTF-8"
+"\x00\x0f;-c;IBM1399;UTF-8"
+"\x0e\x0e;-c;IBM1399;UTF-8"
"\x00\x53;-c;IBM16804;UTF-8//TRANSLIT//IGNORE"
"\x00\x41;-c;IBM274;UTF-8//TRANSLIT//IGNORE"
"\x00\x41;-c;IBM275;UTF-8//TRANSLIT//IGNORE"
@@ -158,24 +158,14 @@ enum
\
if (__builtin_expect (ch, 0) == SO) \
{ \
- /* Shift OUT, change to DBCS converter. */ \
- if (curcs == db) \
- { \
- result = __GCONV_ILLEGAL_INPUT; \
- break; \
- } \
+ /* Shift OUT, change to DBCS converter (redundant escape okay). */ \
curcs = db; \
++inptr; \
continue; \
} \
if (__builtin_expect (ch, 0) == SI) \
{ \
- /* Shift IN, change to SBCS converter. */ \
- if (curcs == sb) \
- { \
- result = __GCONV_ILLEGAL_INPUT; \
- break; \
- } \
+ /* Shift IN, change to SBCS converter (redundant escape okay). */ \
curcs = sb; \
++inptr; \
continue; \