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From: David Howells <dhowells@redhat.com>
To: ChenXiaoSong <chenxiaosong@chenxiaosong.com>
Cc: dhowells@redhat.com, hongao <hongao@uniontech.com>,
	Paulo Alcantara <pc@manguebit.org>,
	netfs@lists.linux.dev, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	syzbot+3c74b1f0c372e98efc32@syzkaller.appspotmail.com
Subject: Re: [PATCH] netfs: Fix UAF in netfs_unbuffered_write() on failed preparation
Date: Tue, 23 Jun 2026 17:10:53 +0100	[thread overview]
Message-ID: <2912807.1782231053@warthog.procyon.org.uk> (raw)
In-Reply-To: <33cc8eb4-8831-49b0-80d6-b06544a37920@chenxiaosong.com>

ChenXiaoSong <chenxiaosong@chenxiaosong.com> wrote:

> After applying this patch, I can still reproduce the use-after-free issue.

Can you get some tracing?  I have a suspicion it's a refcount bug.

The following tracepoints would be useful:

echo 1 > /sys/kernel/tracing/events/netfs/netfs_read/enable
echo 1 > /sys/kernel/tracing/events/netfs/netfs_write/enable
echo 1 > /sys/kernel/tracing/events/netfs/netfs_rreq/enable
echo 1 > /sys/kernel/tracing/events/netfs/netfs_sreq/enable
echo 1 > /sys/kernel/tracing/events/netfs/netfs_failure/enable
echo 1 > /sys/kernel/tracing/events/error_report/enable

And if you can capture this, can you compress the resulting trace and send it
to me?

Thanks,
David


  reply	other threads:[~2026-06-23 16:11 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-30  1:14 [PATCH] netfs: Fix UAF in netfs_unbuffered_write() on failed preparation hongao
2026-06-23 10:28 ` Christian Brauner
2026-06-23 11:52 ` ChenXiaoSong
2026-06-23 16:10   ` David Howells [this message]
2026-06-24  1:26     ` ChenXiaoSong
2026-06-24  7:36       ` David Howells
2026-06-24 10:59       ` David Howells
2026-06-24 11:02       ` David Howells
2026-06-23 14:53 ` David Howells

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