| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 29/62] kconfig: dont crash on NULL expressions in expr_eq() | Date | Sat, 11 Jan 2020 10:50:11 +0100 |
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From: Thomas Hebb <tommyhebb@gmail.com>
[ 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 <tommyhebb@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- 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
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