Dmitry Torokhov a4ff4b54f3 kvm/vfio: ensure kvg instance stays around in kvm_vfio_group_add() ... [ Upstream commit 9e0f4f2918 ] kvm_vfio_group_add() creates kvg instance, links it to kv->group_list, and calls kvm_vfio_file_set_kvm() with kvg->file as an argument after dropping kv->lock. If we race group addition and deletion calls, kvg instance may get freed by the time we get around to calling kvm_vfio_file_set_kvm(). Previous iterations of the code did not reference kvg->file outside of the critical section, but used a temporary variable. Still, they had similar problem of the file reference being owned by kvg structure and potential for kvm_vfio_group_del() dropping it before kvm_vfio_group_add() had a chance to complete. Fix this by moving call to kvm_vfio_file_set_kvm() under the protection of kv->lock. We already call it while holding the same lock when vfio group is being deleted, so it should be safe here as well. Fixes: 2fc1bec158 ("kvm: set/clear kvm to/from vfio_group when group add/delete") Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20230714224538.404793-1-dmitry.torokhov@gmail.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>		2023-09-13 09:42:46 +02:00
..
async_pf.c	KVM: Add helpers to wake/query blocking vCPU	2021-12-08 04:24:54 -05:00
async_pf.h
binary_stats.c	KVM: stats: remove dead stores	2021-08-13 03:35:15 -04:00
coalesced_mmio.c	KVM: Destroy target device if coalesced MMIO unregistration fails	2023-03-10 09:34:11 +01:00
coalesced_mmio.h
dirty_ring.c	KVM: Use acquire/release semantics when accessing dirty ring GFN state	2022-09-29 10:23:08 +01:00
eventfd.c	KVM: eventfd: Fix false positive RCU usage warning	2022-05-20 09:10:33 -04:00
irqchip.c
Kconfig	KVM: Add KVM_CAP_DIRTY_LOG_RING_ACQ_REL capability and config option	2022-09-29 10:23:08 +01:00
kvm_main.c	KVM: Grab a reference to KVM for VM and vCPU stats file descriptors	2023-08-03 10:24:08 +02:00
kvm_mm.h	KVM: SPDX style and spelling fixes	2022-04-21 13:16:13 -04:00
Makefile.kvm	KVM: Reinstate gfn_to_pfn_cache with invalidation support	2022-01-07 10:44:44 -05:00
pfncache.c	KVM: Update gfn_to_pfn_cache khva when it moves within the same page	2022-11-23 18:58:46 -05:00
vfio.c	kvm/vfio: ensure kvg instance stays around in kvm_vfio_group_add()	2023-09-13 09:42:46 +02:00
vfio.h