Messages in this thread | | | Subject | Re: [PATCH] dmabuf: use spinlock to access dmabuf->name | From | Charan Teja Kalla <> | Date | Wed, 17 Jun 2020 19:13:12 +0530 |
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On 6/17/2020 1:51 PM, David Laight wrote: > From: Charan Teja Kalla >> Sent: 17 June 2020 07:29 > ... >>>> If name is freed you will copy garbage, but the only way >>>> for that to happen is that _set_name or _release have to be called >>>> at just the right time. >>>> >>>> And the above would probably only be an issue if the set_name >>>> was called, so you will get NULL or a real name. >> >> And there exists a use-after-free to avoid which requires the lock. Say >> that memcpy() in dmabuffs_dname is in progress and in parallel _set_name >> will free the same buffer that memcpy is operating on. > > If the name is being looked at while the item is being freed > you almost certainly have much bigger problems that just > the name being a 'junk' pointer.
True, thus needs the lock.
> > David. > > - > Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK > Registration No: 1397386 (Wales) >
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