When init struct utf8cursor *u8c in utf8ncursor(), we need check um is
valid.
Reported-and-tested-by: syzbot+9cf75dc581fb4307d6dd@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: b81427939590 ("ext4: remove redundant checks of s_encoding")
Signed-off-by: Edward AD <twuufnxlz@xxxxxxxxx>
---
fs/unicode/utf8-norm.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/fs/unicode/utf8-norm.c b/fs/unicode/utf8-norm.c
index 768f8ab448b8..906b639b2f38 100644
--- a/fs/unicode/utf8-norm.c
+++ b/fs/unicode/utf8-norm.c
@@ -422,6 +422,10 @@ int utf8ncursor(struct utf8cursor *u8c, const struct unicode_map *um,
{
if (!s)
return -1;
+
+ if (IS_ERR_OR_NULL(um))
+ return -1;
+
u8c->um = um;
u8c->n = n;
u8c->s = s;
--
2.25.1
