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From: Stefan Hajnoczi <stefanha@redhat.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Deepanshu Kartikey <kartikey406@gmail.com>,
	axboe@kernel.dk, martin.petersen@oracle.com,
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	syzbot+660d079d90f8a1baf54d@syzkaller.appspotmail.com
Subject: Re: [PATCH] block: add allocation size check in blkdev_pr_read_keys()
Date: Mon, 15 Dec 2025 09:21:18 -0500	[thread overview]
Message-ID: <20251215142118.GA19970@fedora> (raw)
In-Reply-To: <aT-dxw-VSqXMQR_h@infradead.org>

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On Sun, Dec 14, 2025 at 09:33:59PM -0800, Christoph Hellwig wrote:
> On Fri, Dec 12, 2025 at 08:17:43PM +0530, Deepanshu Kartikey wrote:
> > How about limiting num_keys to 64K (1u << 16)? In practice, PR keys
> > are used for shared storage coordination and typical deployments have
> > only a handful of hosts, so this should be more than enough for any
> > realistic use case.
> > 
> > With a bounded num_keys, the SIZE_MAX check becomes unnecessary, so
> > I've removed it. Also switched to kvzalloc/kvfree to handle larger
> > allocations gracefully.
> > 
> > Something like below:
> > 
> > +/* Limit the number of keys to prevent excessive memory allocation */
> > +#define PR_KEYS_MAX_NUM (1u << 16)
> 
> Looks reasonable to me.  Stefan?

Yes, that's good. Thanks for looking into this, Deepanshu.

Stefan

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      reply	other threads:[~2025-12-15 14:21 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-12-12  1:35 [PATCH] block: add allocation size check in blkdev_pr_read_keys() Deepanshu Kartikey
2025-12-12  6:16 ` Christoph Hellwig
2025-12-12 14:47   ` Deepanshu Kartikey
2025-12-15  5:33     ` Christoph Hellwig
2025-12-15 14:21       ` Stefan Hajnoczi [this message]

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