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authorHerbert Xu <herbert@gondor.apana.org.au>2014-10-02 08:26:06 +0800
committerHerbert Xu <herbert@gondor.apana.org.au>2014-10-02 08:26:06 +0800
commit6c3f73bc536082fec38bd36e6c8a121033c68835 (patch)
tree8b1676ccf4edfd5b5b191fc9b248fbebfad131f8 /src
parent[PARSER] Add nlprompt/nlnoprompt helpers (diff)
downloaddash-6c3f73bc536082fec38bd36e6c8a121033c68835.tar.gz
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[EVAL] Fix use-after-free in dotrap/evalstring
The function dotrap calls evalstring using the stored trap string.
If evalstring then unsets that exact trap string then we will end
up using freed memory.

This patch fixes it by making evalstring always duplicate the string
before using it.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'src')
-rw-r--r--src/eval.c3
-rw-r--r--src/histedit.c3
2 files changed, 4 insertions, 2 deletions
diff --git a/src/eval.c b/src/eval.c
index c7358a6..3cfa1e5 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -160,6 +160,7 @@ evalstring(char *s, int flags)
 	struct stackmark smark;
 	int status;
 
+	s = sstrdup(s);
 	setinputstring(s);
 	setstackmark(&smark);
 
@@ -171,7 +172,9 @@ evalstring(char *s, int flags)
 		if (evalskip)
 			break;
 	}
+	popstackmark(&smark);
 	popfile();
+	stunalloc(s);
 
 	return status;
 }
diff --git a/src/histedit.c b/src/histedit.c
index b27d629..94465d7 100644
--- a/src/histedit.c
+++ b/src/histedit.c
@@ -372,8 +372,7 @@ histcmd(int argc, char **argv)
 					out2str(s);
 				}
 
-				evalstring(strcpy(stalloc(strlen(s) + 1), s),
-					   0);
+				evalstring(s, 0);
 				if (displayhist && hist) {
 					/*
 					 *  XXX what about recursive and