This is a note to let you know that I've just added the patch titled
kconfig: don't crash on NULL expressions in expr_eq()
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kconfig-don-t-crash-on-null-expressions-in-expr_eq.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ced83f23c29e8ebc67158136c52203a30805c832
Author: Thomas Hebb <tommyhebb@xxxxxxxxx>
Date: Mon Dec 9 00:19:17 2019 -0800
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 <tommyhebb@xxxxxxxxx>
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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) {
