From: Tejun Heo <tj@kernel.org>
To: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Zefan Li <lizefan@huawei.com>,
syzbot <syzbot+87b93137e0280beaeba1@syzkaller.appspotmail.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk
Subject: Re: WARNING: lock held when returning to user space in grab_super
Date: Wed, 2 Jan 2019 08:55:28 -0800 [thread overview]
Message-ID: <20190102165528.GT2509588@devbig004.ftw2.facebook.com> (raw)
In-Reply-To: <19260f8b-d831-9a9a-5315-1f4353dadc9b@i-love.sakura.ne.jp>
On Thu, Jan 03, 2019 at 01:49:55AM +0900, Tetsuo Handa wrote:
> kernfs_node_dentry() calls lookup_one_len_unlocked() which involves
> memory allocation, and memory allocation fault injection made
> lookup_one_len_unlocked() fail, and thus kernfs_node_dentry() failed.
> What's strange?
So, kernfs_node_dentry() is called on the root kn, which should
trigger "if (!kn->parent) return dentry" in kernfs_node_dentry(), so
it shouldn't reach lookup_on_len_unlocked(). Oh I see. This is the
namespaced mount path, so kn can be non-root. Will fix it.
Thanks.
--
tejun
prev parent reply other threads:[~2019-01-02 16:55 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-02 12:06 WARNING: lock held when returning to user space in grab_super syzbot
2019-01-02 12:08 ` Tetsuo Handa
2019-01-02 16:16 ` Tejun Heo
2019-01-02 16:49 ` Tetsuo Handa
2019-01-02 16:55 ` Tejun Heo [this message]
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