Messages in this thread | | | Subject | Re: [PATCH] fs/block_dev: fix potential NULL ptr deref in freeze_bdev() | From | Jens Axboe <> | Date | Thu, 25 Aug 2016 08:39:22 -0600 |
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On 08/23/2016 09:55 AM, Andrey Ryabinin wrote: > Calling freeze_bdev() twice on the same block device without mounted > filesystem get_super() will return NULL, which will lead to NULL-ptr > dereference later in drop_super(). > > Check get_super() result to fix that. > > Note, that this is a purely theoretical issue. We have only 3 > freeze_bdev() callers. 2 of them are in filesystem code and used on a > device with mounted fs. The third one in lock_fs() has protection in > upper-layer code against freezing block device the second time without > thawing it first.
Applied, thanks.
-- Jens Axboe
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