From d6cbda49aaa5a5288b37741fd6bf5ced87742647 Mon Sep 17 00:00:00 2001
From: weishu <twsxtd@gmail.com>
Date: Wed, 27 Dec 2023 20:19:21 +0800
Subject: [PATCH] kernel: fix out of bound reading. close #1227

---
 kernel/allowlist.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/allowlist.c b/kernel/allowlist.c
index f1115eb5..2c32bbb5 100644
--- a/kernel/allowlist.c
+++ b/kernel/allowlist.c
@@ -458,7 +458,9 @@ void ksu_prune_allowlist(bool (*is_uid_valid)(uid_t, char *, void *), void *data
 			modified = true;
 			pr_info("prune uid: %d, package: %s\n", uid, package);
 			list_del(&np->list);
-			allow_list_bitmap[uid / BITS_PER_BYTE] &= ~(1 << (uid % BITS_PER_BYTE));
+			if (likely(uid <= BITMAP_UID_MAX)) {
+				allow_list_bitmap[uid / BITS_PER_BYTE] &= ~(1 << (uid % BITS_PER_BYTE));
+			}
 			remove_uid_from_arr(uid);
 			smp_mb();
 			kfree(np);