From d8ae6c00a945aadc971cf2c33d9fb0ed31ebb5df Mon Sep 17 00:00:00 2001 From: Arjun Shankar Date: Wed, 4 Nov 2020 12:19:38 +0100 Subject: [PATCH] iconv: Accept redundant shift sequences in IBM1364 [BZ #26224] 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). Reviewed-by: Carlos O'Donell (cherry picked from commit 9a99c682144bdbd40792ebf822fe9264e0376fb5) --- NEWS | 6 ++++++ iconv/tst-iconv_prog.sh | 16 ++++++++++------ iconvdata/ibm1364.c | 14 ++------------ 3 files changed, 18 insertions(+), 18 deletions(-) diff --git a/NEWS b/NEWS index cc36b41dbaa..95d69cd07ee 100644 --- a/NEWS +++ b/NEWS @@ -92,6 +92,10 @@ Security related changes: corruption when they were passed a pseudo-zero argument. Reported by Guido Vranken / ForAllSecure Mayhem. + CVE-2020-27618: An infinite loop has been fixed in the iconv program when + invoked with input containing redundant shift sequences in the IBM1364, + IBM1371, IBM1388, IBM1390, or IBM1399 character sets. + The following bugs are resolved with this release: [6889] 'PWD' mentioned but not specified @@ -183,6 +187,8 @@ The following bugs are resolved with this release: [25423] Array overflow in backtrace on powerpc [25487] sinl() stack corruption from crafted input (CVE-2020-10029) [25620] libc: Signed comparison vulnerability in the ARMv7 memcpy() (CVE-2020-6096) + [26224] iconv hangs when converting some invalid inputs from several IBM + character sets (CVE-2020-27618) [26383] bind_textdomain_codeset doesn't accept //TRANSLIT anymore diff --git a/iconv/tst-iconv_prog.sh b/iconv/tst-iconv_prog.sh index 8298136b7f4..d8db7b335c1 100644 --- a/iconv/tst-iconv_prog.sh +++ b/iconv/tst-iconv_prog.sh @@ -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" diff --git a/iconvdata/ibm1364.c b/iconvdata/ibm1364.c index b833273aa83..27900c4307c 100644 --- a/iconvdata/ibm1364.c +++ b/iconvdata/ibm1364.c @@ -157,24 +157,14 @@ 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; \ -- 2.47.2