On 03/05/2018 05:58 PM, Nicolas Iooss wrote:
cil_tree_print_expr() calls cil_expr_to_string() in order to compute a
string expression into expr_str. If this function fails, expr_str is
left unitialized but its value is dereferenced with:
cil_log(CIL_INFO, "%s)", expr_str);
Prevent such an issue by checking cil_expr_to_string()'s return value
before using expr_str.
This issue has been found with clang's static analyzer.
Signed-off-by: Nicolas Iooss <nicolas.iooss@xxxxxxx>
Acked-by: James Carter <jwcart2@xxxxxxxxxxxxx>
---
libsepol/cil/src/cil_tree.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/libsepol/cil/src/cil_tree.c b/libsepol/cil/src/cil_tree.c
index d36401b41dba..b394a9d849df 100644
--- a/libsepol/cil/src/cil_tree.c
+++ b/libsepol/cil/src/cil_tree.c
@@ -503,15 +503,19 @@ exit:
void cil_tree_print_expr(struct cil_list *datum_expr, struct cil_list *str_expr)
{
char *expr_str;
+ int rc;
cil_log(CIL_INFO, "(");
if (datum_expr != NULL) {
- cil_expr_to_string(datum_expr, &expr_str);
+ rc = cil_expr_to_string(datum_expr, &expr_str);
} else {
- cil_expr_to_string(str_expr, &expr_str);
+ rc = cil_expr_to_string(str_expr, &expr_str);
+ }
+ if (rc < 0) {
+ cil_log(CIL_INFO, "ERROR)");
+ return;
}
-
cil_log(CIL_INFO, "%s)", expr_str);
free(expr_str);
}
--
James Carter <jwcart2@xxxxxxxxxxxxx>
National Security Agency
