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Groups > linux.kernel > #1721040
| From | Paul Mackerras <paulus@ozlabs.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: Re: [PATCH] fix memory leak on kvm_vm_ioctl_create_spapr_tce |
| Date | 2017-08-28 08:10 +0200 |
| Message-ID | <ujlpi-1UB-53@gated-at.bofh.it> (permalink) |
| References | (3 earlier) <uhsXU-2lI-15@gated-at.bofh.it> <uhx1v-5kg-3@gated-at.bofh.it> <ujcYG-4GL-11@gated-at.bofh.it> <ujk9P-VX-15@gated-at.bofh.it> <ujkMy-1pK-21@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Mon, Aug 28, 2017 at 06:28:08AM +0100, Al Viro wrote: > On Mon, Aug 28, 2017 at 02:38:37PM +1000, Paul Mackerras wrote: > > On Sun, Aug 27, 2017 at 10:02:20PM +0100, Al Viro wrote: > > > On Wed, Aug 23, 2017 at 04:06:24PM +1000, Paul Mackerras wrote: > > > > > > > It seems to me that it would be better to do the anon_inode_getfd() > > > > call before the kvm_get_kvm() call, and go to the fail label if it > > > > fails. > > > > > > And what happens if another thread does close() on the (guessed) fd? > > > > Chaos ensues, but mostly because we don't have proper mutual exclusion > > on the modifications to the list. I'll add a mutex_lock/unlock to > > kvm_spapr_tce_release() and move the anon_inode_getfd() call inside > > the mutex. > > > > It looks like the other possible uses of the fd (mmap, and passing it > > as a parameter to the KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE ioctl on a KVM > > device fd) are safe. > > Frankly, it's a lot saner to have "no failure points past anon_inode_getfd()" > policy... Right. In my latest patch, there are no failure points past anon_inode_getfd(). Paul.
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Re: Re: [PATCH] fix memory leak on kvm_vm_ioctl_create_spapr_tce Al Viro <viro@ZenIV.linux.org.uk> - 2017-08-27 23:10 +0200
Re: Re: [PATCH] fix memory leak on kvm_vm_ioctl_create_spapr_tce Paul Mackerras <paulus@ozlabs.org> - 2017-08-28 06:50 +0200
Re: Re: [PATCH] fix memory leak on kvm_vm_ioctl_create_spapr_tce Al Viro <viro@ZenIV.linux.org.uk> - 2017-08-28 07:30 +0200
Re: Re: [PATCH] fix memory leak on kvm_vm_ioctl_create_spapr_tce Paul Mackerras <paulus@ozlabs.org> - 2017-08-28 08:10 +0200
Re: Re: [PATCH] fix memory leak on kvm_vm_ioctl_create_spapr_tce Michael Ellerman <mpe@ellerman.id.au> - 2017-08-28 13:40 +0200
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