Bug 176250

Summary: [libc] [patch] euc locale input modifies data
Product: Base System Reporter: J.R. Oldroyd <fbsd>
Component: binAssignee: Baptiste Daroussin <bapt>
Status: Closed FIXED    
Severity: Affects Only Me CC: theraven, yuripv
Priority: Normal    
Version: 9.1-RELEASE   
Hardware: Any   
OS: Any   
Attachments:
Description Flags
file.diff none

Description J.R. Oldroyd 2013-02-18 17:10:00 UTC 
When reading an invalid multibyte data sequence while set to an euc locale,
e.g., ja_JP.eucJP, the src/lib/libc/locale/euc.c code will modify the bytes
read to ensure that the 0x8080 or 0x808080 bits are set.  This has the
effect of silently returning data other than that which was in the input.
There is then no way of detecting that the input sequence was invalid.

The correct behavior is to test that those bits are set, return the data
if they are, but return EILSEQ if not.

Fix is applicable to 10-current and 9-stable.  Please MFC.

How-To-Repeat: 1. Create test file containing invalid euc multibyte characters such as:
	0xa440 0xac4f 0xb36f 0xcf20
2. Set locale to, e.g., ja_JP.eucJP.
3. Read characters from file using getwc().  Observe that what's read is:
	0xa4c0 0xaccf 0xb3ef 0xcfa0
Comment 1 David Chisnall freebsd_committer freebsd_triage 2015-10-08 16:29:31 UTC 
The change looks fine to me, but I'd like the opinion of someone familiar with the character set in question.
Comment 2 Eitan Adler freebsd_committer freebsd_triage 2018-05-28 19:49:00 UTC 
batch change:

For bugs that match the following
-  Status Is In progress 
AND
- Untouched since 2018-01-01.
AND
- Affects Base System OR Documentation

DO:

Reset to open status.


Note:
I did a quick pass but if you are getting this email it might be worthwhile to double check to see if this bug ought to be closed.
Comment 3 Yuri Pankov freebsd_committer freebsd_triage 2018-11-17 00:11:39 UTC 
lib/libc/locale/euc.c was revamped in base r286459, and the problem is no longer there.