From 57d09d7dbfe6a5956c4c0828141a4cad59624549 Mon Sep 17 00:00:00 2001
From: Sheng Yong <shengyong1@huawei.com>
Date: Tue, 19 Nov 2019 17:46:48 +0800
Subject: [PATCH] f2fs: check if file namelen exceeds max value

mainline inclusion
from mainline-v5.1-rc1
commit 720db068634c91553a8e1d9a0fcd8c7050e06d2b
category: bugfix
bugzilla: 13690
CVE: CVE-2019-9445

-------------------------------------------------

Dentry bitmap is not enough to detect incorrect dentries. So this patch
also checks the namelen value of a dentry.

Signed-off-by: Gong Chen <gongchen4@huawei.com>
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Wei Fang <fangwei1@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 fs/f2fs/dir.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 36961c9b3163..f73c9e5ea936 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -812,7 +812,8 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
 
 		/* check memory boundary before moving forward */
 		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
-		if (unlikely(bit_pos > d->max)) {
+		if (unlikely(bit_pos > d->max ||
+				le16_to_cpu(de->name_len) > F2FS_NAME_LEN)) {
 			f2fs_msg(sbi->sb, KERN_WARNING,
 				"%s: corrupted namelen=%d, run fsck to fix.",
 				__func__, le16_to_cpu(de->name_len));
-- 
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