ash: fix use-after-free in bash pattern substitution
function old new delta
subevalvar 1566 1564 -2
Signed-off-by: Sören Tempel <soeren@soeren-tempel.net>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash.c b/shell/ash.c
index 105edd4..55c1034 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -7357,6 +7357,13 @@
idx = loc;
}
+ /* The STPUTC invocations above may resize and move the
+ * stack via realloc(3). Since repl is a pointer into the
+ * stack, we need to reconstruct it relative to stackblock().
+ */
+ if (slash_pos >= 0)
+ repl = (char *)stackblock() + strloc + slash_pos + 1;
+
//bb_error_msg("repl:'%s'", repl);
for (loc = (char*)repl; *loc; loc++) {
char *restart_detect = stackblock();