From: Matthew Wilcox <willy@infradead.org>
To: "Pankaj Raghav (Samsung)" <kernel@pankajraghav.com>
Cc: Christoph Hellwig <hch@lst.de>,
Chandan Babu R <chandan.babu@oracle.com>,
"Darrick J. Wong" <djwong@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org, p.raghav@samsung.com
Subject: Re: [PATCH 2/3] xfs: convert perag lookup to xarray
Date: Mon, 12 Aug 2024 20:02:36 +0100 [thread overview]
Message-ID: <ZrpcTAuJFSzE4-nA@casper.infradead.org> (raw)
In-Reply-To: <20240812163956.xduakibqyzuapfkt@quentin>
On Mon, Aug 12, 2024 at 04:39:56PM +0000, Pankaj Raghav (Samsung) wrote:
> On Mon, Aug 12, 2024 at 08:31:01AM +0200, Christoph Hellwig wrote:
> > diff --git a/fs/xfs/libxfs/xfs_ag.c b/fs/xfs/libxfs/xfs_ag.c
> > index 7e80732cb54708..5efb1e8b4107a9 100644
> > --- a/fs/xfs/libxfs/xfs_ag.c
> > +++ b/fs/xfs/libxfs/xfs_ag.c
> > @@ -46,7 +46,7 @@ xfs_perag_get(
> > struct xfs_perag *pag;
> >
> > rcu_read_lock();
> xa_load() already calls rcu_read_lock(). So we can get rid of this I
> guess?
Almost certainly not; I assume pag is RCU-freed, so you'd be introducing
a UAF if the RCU lock is dropped before getting a refcount on the pag.
next prev parent reply other threads:[~2024-08-12 19:02 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-12 6:30 conver XFS perag lookup to xarrays Christoph Hellwig
2024-08-12 6:31 ` [PATCH 1/3] xarray: add xa_set Christoph Hellwig
2024-08-12 12:25 ` Matthew Wilcox
2024-08-12 12:28 ` Christoph Hellwig
2024-08-12 6:31 ` [PATCH 2/3] xfs: convert perag lookup to xarray Christoph Hellwig
2024-08-12 14:39 ` Matthew Wilcox
2024-08-12 14:43 ` Christoph Hellwig
2024-08-12 16:39 ` Pankaj Raghav (Samsung)
2024-08-12 19:02 ` Matthew Wilcox [this message]
2024-08-13 8:30 ` Pankaj Raghav (Samsung)
2024-08-13 6:37 ` kernel test robot
2024-08-14 4:59 ` Dave Chinner
2024-08-14 5:21 ` Christoph Hellwig
2024-08-12 6:31 ` [PATCH 3/3] xfs: use kfree_rcu_mightsleep to free the perag structures Christoph Hellwig
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