klibc - Mar 2020 - [klibc:update-dash] dash: [BUILTIN] Fixed argument parsing crash in test

Commit-ID:  f82f85d8be5ced5e6728792fea1a6dc089decf59
Gitweb:    
http://git.kernel.org/?p=libs/klibc/klibc.git;a=commit;h=f82f85d8be5ced5e6728792fea1a6dc089decf59
Author:     Herbert Xu <herbert at gondor.apana.org.au>
AuthorDate: Fri, 23 Aug 2013 21:58:55 +1000
Committer:  Ben Hutchings <ben at decadent.org.uk>
CommitDate: Sat, 28 Mar 2020 21:42:54 +0000

[klibc] dash: [BUILTIN] Fixed argument parsing crash in test

[ dash commit b34499f5c851d1a70db95b56bd02eff0329d4a1a ]

When nexpr gets an unexpected EOI, this may cause crashes further
up the call chain because we've advanced t_wp too far.  Fix it by
checking for EOI in nexpr and only advancing t_wp if we've got more
arguments.

Signed-off-by: Herbert Xu <herbert at gondor.apana.org.au>
Signed-off-by: Ben Hutchings <ben at decadent.org.uk>

---
 usr/dash/bltin/test.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/usr/dash/bltin/test.c b/usr/dash/bltin/test.c
index 90135e14..baa91a57 100644
--- a/usr/dash/bltin/test.c
+++ b/usr/dash/bltin/test.c
@@ -268,9 +268,13 @@ aexpr(enum token n)
 static int
 nexpr(enum token n)
 {
-	if (n == UNOT)
-		return !nexpr(t_lex(++t_wp));
-	return primary(n);
+	if (n != UNOT)
+		return primary(n);
+
+	n = t_lex(t_wp + 1);
+	if (n != EOI)
+		t_wp++;
+	return !nexpr(n);
 }
 
 static int