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From: Michael Forney <mforney@mforney.org>
To: musl@lists.openwall.com
Subject: [PATCH] mbsrtowcs: Fix bug when wn is a multiple of 4
Date: Fri, 27 Sep 2013 01:54:42 -0700	[thread overview]
Message-ID: <1380272082-13878-1-git-send-email-mforney@mforney.org> (raw)

If wn becomes 0 after processing a chunk of 4, mbsrtowcs currently
continues on, wrapping wn around to -1, causing the rest of the string
to be processed.

This resulted in buffer overruns if there was only space in ws for wn
wide characters.
---
Hi,

I found this bug while tracking down a SIGSEGV in bash when globbing a large
pattern.

 src/multibyte/mbsrtowcs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/multibyte/mbsrtowcs.c b/src/multibyte/mbsrtowcs.c
index b9bbc33..c5a30de 100644
--- a/src/multibyte/mbsrtowcs.c
+++ b/src/multibyte/mbsrtowcs.c
@@ -66,6 +66,7 @@ resume0:
 				*ws++ = *s++;
 				wn -= 4;
 			}
+			if (!wn) continue;
 		}
 		if (*s-1u < 0x7f) {
 			*ws++ = *s++;
-- 
1.8.4



             reply	other threads:[~2013-09-27  8:54 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-27  8:54 Michael Forney [this message]
2013-09-27 15:28 ` Rich Felker
2013-09-27 15:56   ` Rich Felker
2013-09-27 22:43     ` Michael Forney

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