From 16b9c5c49b4131a63f1e108b23ba2399c241fd87 Mon Sep 17 00:00:00 2001 From: Thomas Hebb Date: Mon, 9 Dec 2019 00:19:17 -0800 Subject: [PATCH] kconfig: don't crash on NULL expressions in expr_eq() [ Upstream commit 272a72103012862e3a24ea06635253ead0b6e808 ] NULL expressions are taken to always be true, as implemented by the expr_is_yes() macro and by several other functions in expr.c. As such, they ought to be valid inputs to expr_eq(), which compares two expressions. Signed-off-by: Thomas Hebb Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin --- scripts/kconfig/expr.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/scripts/kconfig/expr.c b/scripts/kconfig/expr.c index ed29bad1f03a..96420b620963 100644 --- a/scripts/kconfig/expr.c +++ b/scripts/kconfig/expr.c @@ -201,6 +201,13 @@ static int expr_eq(struct expr *e1, struct expr *e2) { int res, old_count; + /* + * A NULL expr is taken to be yes, but there's also a different way to + * represent yes. expr_is_yes() checks for either representation. + */ + if (!e1 || !e2) + return expr_is_yes(e1) && expr_is_yes(e2); + if (e1->type != e2->type) return 0; switch (e1->type) { -- 2.20.1