Nicholas Piggin dd8ed6c9bc KVM: do not allow mapping valid but non-reference-counted pages ... commit f8be156be163a052a067306417cd0ff679068c97 upstream. It's possible to create a region which maps valid but non-refcounted pages (e.g., tail pages of non-compound higher order allocations). These host pages can then be returned by gfn_to_page, gfn_to_pfn, etc., family of APIs, which take a reference to the page, which takes it from 0 to 1. When the reference is dropped, this will free the page incorrectly. Fix this by only taking a reference on valid pages if it was non-zero, which indicates it is participating in normal refcounting (and can be released with put_page). This addresses CVE-2021-22543. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Paolo Bonzini <pbonzini@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-06-30 08:47:25 -04:00
..
async_pf.c	mm/gup: remove task_struct pointer for all gup code	2020-08-12 10:58:04 -07:00
async_pf.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504	2019-06-19 17:09:56 +02:00
coalesced_mmio.c	KVM: Stop looking for coalesced MMIO zones if the bus is destroyed	2021-05-14 09:50:04 +02:00
coalesced_mmio.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
eventfd.c	kvm/eventfd: move wildcard calculation outside loop	2020-09-28 07:57:08 -04:00
irqchip.c	KVM/arm updates for 5.3	2019-07-11 15:14:16 +02:00
Kconfig	entry: Provide infrastructure for work before transitioning to guest mode	2020-07-24 15:03:42 +02:00
kvm_main.c	KVM: do not allow mapping valid but non-reference-counted pages	2021-06-30 08:47:25 -04:00
vfio.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
vfio.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00