[PATCH 4.19 10/84] f2fs: check if file namelen exceeds max value

Greg Kroah-Hartman
2020-01-16T23:40:08Z

From: Sheng Yong <shengyong1@huawei.com>

commit 720db068634c91553a8e1d9a0fcd8c7050e06d2b upstream.

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: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/f2fs/dir.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -808,7 +808,8 @@ int f2fs_fill_dentries(struct dir_contex

/* 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));