From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Alexander Viro <viro@zeniv.linux.org.uk>
Cc: akpm@linux-foundation.org, hughd@google.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
syzkaller-bugs@googlegroups.com,
syzbot <syzbot+702361cf7e3d95758761@syzkaller.appspotmail.com>,
Dmitry Vyukov <dvyukov@google.com>
Subject: Re: [syzbot] [mm?] KCSAN: data-race in generic_fillattr / shmem_mknod (2)
Date: Mon, 1 May 2023 23:05:35 +0900 [thread overview]
Message-ID: <a2c2308a-729a-ec18-18e7-36d00b25207d@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <bdb1fe2d-f904-78f0-d287-5e601f789862@I-love.SAKURA.ne.jp>
On 2023/05/01 14:15, Tetsuo Handa wrote:
> Hmm, where is the serialization that avoids concurrent
> shmem_mknod()/shmem_mknod() or shmem_mknod()/shmem_unlink() ?
> i_size_write() says "need locking around it (normally i_mutex)"...
>
Since filename_create() calls inode_lock_nested(path->dentry->d_inode, I_MUTEX_PARENT)
and done_path_create() calls inode_unlock(path->dentry->d_inode), serialization looks OK.
Just the name is no longer i_mutex ?
> Also, there was a similar report on updating i_{ctime,mtime} to current_time()
> which means that i_size is not the only field that is causing data race.
> https://syzkaller.appspot.com/bug?id=067d40ab9ab23a6fa0a8156857ed54e295062a29
Do we want to as well wrap i_{ctime,mtime} using data_race() ?
next prev parent reply other threads:[~2023-05-01 14:06 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-24 7:58 syzbot
[not found] ` <CACT4Y+a=xWkNGw_iKibRp4ivSE8OJkWWT0VPQ4N4d1+vj0FMdg@mail.gmail.com>
2023-05-01 5:15 ` Tetsuo Handa
2023-05-01 14:05 ` Tetsuo Handa [this message]
2023-05-02 10:13 ` Tetsuo Handa
2023-05-02 6:13 ` Dmitry Vyukov
2024-01-12 12:15 ` syzbot
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