From: Al Viro <viro@zeniv.linux.org.uk>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: syzbot <syzbot+ecccecbc636b455f9084@syzkaller.appspotmail.com>,
gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com, tj@kernel.org,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] kernfs: Drop kernfs_rwsem while invoking lookup_positive_unlocked().
Date: Thu, 20 Feb 2025 20:39:24 +0000 [thread overview]
Message-ID: <20250220203924.GL1977892@ZenIV> (raw)
In-Reply-To: <20250218163938.xmvjlJ0K@linutronix.de>
On Tue, Feb 18, 2025 at 05:39:38PM +0100, Sebastian Andrzej Siewior wrote:
> + scoped_guard(rcu) {
> + knparent = find_next_ancestor(kn, NULL);
> + if (WARN_ON(!knparent)) {
> + dput(dentry);
> + return ERR_PTR(-EINVAL);
> + }
NAK. dput() is blocking; you *can't* do that under rcu_read_lock().
next prev parent reply other threads:[~2025-02-20 20:39 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-18 9:27 [syzbot] [kernfs?] WARNING: suspicious RCU usage in kernfs_node_dentry syzbot
2025-02-18 16:39 ` [PATCH] kernfs: Drop kernfs_rwsem while invoking lookup_positive_unlocked() Sebastian Andrzej Siewior
2025-02-18 19:21 ` Tejun Heo
2025-02-20 20:39 ` Al Viro [this message]
2025-02-21 7:49 ` Sebastian Andrzej Siewior
2025-02-21 8:42 ` [PATCH] kernfs: Move dput() outside of the RCU section Sebastian Andrzej Siewior
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