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From: "zhangxiaoxu (A)" <zhangxiaoxu5@huawei.com>
To: <tao.lyu@epfl.ch>, Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: ChenXiaoSong <chenxiaosong2@huawei.com>,
	yanaijie <yanaijie@huawei.com>,
	"zhangyi (F)" <yi.zhang@huawei.com>,
	Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Question about CVE-2022-24448
Date: Tue, 8 Feb 2022 19:48:58 +0800	[thread overview]
Message-ID: <1bb42908-8f58-bf56-c2da-42739ee48d16@huawei.com> (raw)

Hi Trond and Tao,

I have some question about CVE-2022-24448[1].

It's description as:
   An issue was discovered in fs/nfs/dir.c in the Linux kernel before 5.16.5.
   If an application sets the O_DIRECTORY flag, and tries to open a regular
   file, nfs_atomic_open() performs a regular lookup. If a regular file is
   found, ENOTDIR should occur, but the server instead returns uninitialized
   data in the file descriptor.

It's fixed by ac795161c936 ("NFSv4: Handle case where the lookup of a directory fails")

When try to open a regular file with O_DIRECTORY flag,
it always return -ENOTDIR to userspace rather than a
valid file descriptor because the 'do_open' check the
dentry type.

My questions are:
1. which uninitialized data in the file description are returned from 'nfs_atomic_open'?
2. where use the uninitialized data?
3. which uninitialized data are returned from server?
4. is there a PoC reproducer or how to trigger it?


[1] https://nvd.nist.gov/vuln/detail/CVE-2022-24448

             reply	other threads:[~2022-02-08 11:51 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-08 11:48 zhangxiaoxu (A) [this message]
     [not found] ` <4e965ca75c4c4b70ac3322c39873d418@epfl.ch>
2022-02-09 11:28   ` Question about CVE-2022-24448 zhangxiaoxu (A)

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