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From:   Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
To:     <richard@nod.at>
CC:     <chengzhihao1@huawei.com>, <linux-mtd@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <yusongping@huawei.com>,
        <artem.kuzin@huawei.com>
Subject: [PATCH] ubifs: fix possible dereference after free
Date:   Tue, 5 Sep 2023 18:12:22 +0800
Message-ID: <20230905101222.1725230-1-konstantin.meskhidze@huawei.com>
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Precedence: bulk

'old_idx' could be dereferenced after free via 'rb_link_node' function
call.

Fixes: b5fda08ef213 ("ubifs: Fix memleak when insert_old_idx() failed")
Co-developed-by: Ivanov Mikhail <ivanov.mikhail1@huawei-partners.com>
Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
---
 fs/ubifs/tnc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index 6b7d95b65f4b..f4728e65d1bd 100644
--- a/fs/ubifs/tnc.c
+++ b/fs/ubifs/tnc.c
@@ -64,8 +64,9 @@ static void do_insert_old_idx(struct ubifs_info *c,
 			p = &(*p)->rb_right;
 		else {
 			ubifs_err(c, "old idx added twice!");
 			kfree(old_idx);
+			return;
 		}
 	}
 	rb_link_node(&old_idx->rb, parent, p);
 	rb_insert_color(&old_idx->rb, &c->old_idx);
-- 
2.34.1