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authorMike Frysinger <vapier@gentoo.org>2009-10-18 05:11:45 (GMT)
committer Mike Frysinger <vapier@gentoo.org>2009-10-18 05:15:36 (GMT)
commit28736c36ca6a73864324296117ce26c9a23066dd (patch)
tree932f02ded50c8df7db9a7eea3063c2ed6c841fc1
parent69d9edc6f8387ed0ec4742a5de895b22b3910818 (diff)
downloadbusybox-28736c36ca6a73864324296117ce26c9a23066dd.tar.gz
busybox-28736c36ca6a73864324296117ce26c9a23066dd.tar.bz2
hush: handle empty execs
Sometimes variable expansions yield empty strings, and if they happen to be a command someone wants to run like `$foo`, then hush currently segfaults. So handle `` and $(). Signed-off-by: Mike Frysinger <vapier@gentoo.org>
-rw-r--r--shell/hush.c6
-rw-r--r--shell/hush_test/hush-psubst/emptytick.right14
-rwxr-xr-xshell/hush_test/hush-psubst/emptytick.tests16
3 files changed, 36 insertions, 0 deletions
diff --git a/shell/hush.c b/shell/hush.c
index 2d333d7..1d2826d 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -3895,6 +3895,12 @@ static NOINLINE int run_pipe(struct pipe *pi)
argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
}
+ /* if someone gives us an empty string: ``, $(), ... */
+ if (!argv_expanded[0]) {
+ debug_leave();
+ return 0;
+ }
+
x = find_builtin(argv_expanded[0]);
#if ENABLE_HUSH_FUNCTIONS
funcp = NULL;
diff --git a/shell/hush_test/hush-psubst/emptytick.right b/shell/hush_test/hush-psubst/emptytick.right
new file mode 100644
index 0000000..d4b70c5
--- /dev/null
+++ b/shell/hush_test/hush-psubst/emptytick.right
@@ -0,0 +1,14 @@
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
diff --git a/shell/hush_test/hush-psubst/emptytick.tests b/shell/hush_test/hush-psubst/emptytick.tests
new file mode 100755
index 0000000..af3a183
--- /dev/null
+++ b/shell/hush_test/hush-psubst/emptytick.tests
@@ -0,0 +1,16 @@
+true; ``; echo $?
+false; ``; echo $?
+true; `""`; echo $?
+false; `""`; echo $?
+true; ` `; echo $?
+false; ` `; echo $?
+
+true; $(); echo $?
+false; $(); echo $?
+true; $(""); echo $?
+false; $(""); echo $?
+true; $( ); echo $?
+false; $( ); echo $?
+
+true; exec ''; echo $?
+false; exec ''; echo $?