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From: Christoph Hellwig <hch@lst.de>
To: Carlos Maiolino <cmaiolino@redhat.com>
Cc: linux-fsdevel@vger.kernel.org, hch@lst.de,
	darrick.wong@oracle.com, sandeen@sandeen.net
Subject: Re: [PATCH 5/5] fibmap: Reject negative block numbers
Date: Fri, 22 Nov 2019 14:38:37 +0100	[thread overview]
Message-ID: <20191122133837.GD25822@lst.de> (raw)
In-Reply-To: <20191122085320.124560-6-cmaiolino@redhat.com>

On Fri, Nov 22, 2019 at 09:53:20AM +0100, Carlos Maiolino wrote:
> FIBMAP receives an integer from userspace which is then implicitly converted
> into sector_t to be passed to bmap(). No check is made to ensure userspace
> didn't send a negative block number, which can end up in an underflow, and
> returning to userspace a corrupted block address.
> 
> As a side-effect, the underflow caused by a negative block here, will
> trigger the WARN() in iomap_bmap_actor(), which is how this issue was
> first discovered.
> 
> This is essentially a V2 of a patch I sent a while ago, reworded and
> refactored to fit into this patchset.

That last sentence should probably be removed.

Otherwise:

Reviewed-by: Christoph Hellwig <hch@lst.de>

  reply	other threads:[~2019-11-22 13:38 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-22  8:53 [PATCH 0/5] Refactor ioctl_fibmap() internal interface Carlos Maiolino
2019-11-22  8:53 ` [PATCH 1/5] fs: Enable bmap() function to properly return errors Carlos Maiolino
2019-11-22 13:37   ` Christoph Hellwig
2019-11-22 14:02     ` Carlos Maiolino
2019-11-22 14:07       ` Christoph Hellwig
2019-11-22  8:53 ` [PATCH 2/5] cachefiles: drop direct usage of ->bmap method Carlos Maiolino
2019-11-22 13:37   ` Christoph Hellwig
2019-11-22 14:04     ` Carlos Maiolino
2019-11-22  8:53 ` [PATCH 3/5] ecryptfs: drop direct calls to ->bmap Carlos Maiolino
2019-11-22  8:53 ` [PATCH 4/5] fibmap: Use bmap instead of ->bmap method in ioctl_fibmap Carlos Maiolino
2019-11-22 13:38   ` Christoph Hellwig
2019-11-24  9:56   ` kbuild test robot
2019-11-24 14:52   ` kbuild test robot
2019-11-22  8:53 ` [PATCH 5/5] fibmap: Reject negative block numbers Carlos Maiolino
2019-11-22 13:38   ` Christoph Hellwig [this message]
  -- strict thread matches above, loose matches on Subject: below --
2019-12-10 15:03 [PATCH 0/5] Refactor ioctl_fibmap() internal interface Carlos Maiolino
2019-12-10 15:03 ` [PATCH 5/5] fibmap: Reject negative block numbers Carlos Maiolino
2020-01-09 13:30 [PATCH V8 0/5] Refactor ioctl_fibmap() internal interface Carlos Maiolino
2020-01-09 13:30 ` [PATCH 5/5] fibmap: Reject negative block numbers Carlos Maiolino

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