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alistair23-linux/virt/kvm
Andre Przywara b3aff6ccbb KVM: arm/arm64: Fix reference to uninitialised VGIC
Commit 4b4b4512da ("arm/arm64: KVM: Rework the arch timer to use
level-triggered semantics") brought the virtual architected timer
closer to the VGIC. There is one occasion were we don't properly
check for the VGIC actually having been initialized before, but
instead go on to check the active state of some IRQ number.
If userland hasn't instantiated a virtual GIC, we end up with a
kernel NULL pointer dereference:
=========
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = ffffffc9745c5000
[00000000] *pgd=00000009f631e003, *pud=00000009f631e003, *pmd=0000000000000000
Internal error: Oops: 96000006 [#2] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 2144 Comm: kvm_simplest-ar Tainted: G      D 4.5.0-rc2+ #1300
Hardware name: ARM Juno development board (r1) (DT)
task: ffffffc976da8000 ti: ffffffc976e28000 task.ti: ffffffc976e28000
PC is at vgic_bitmap_get_irq_val+0x78/0x90
LR is at kvm_vgic_map_is_active+0xac/0xc8
pc : [<ffffffc0000b7e28>] lr : [<ffffffc0000b972c>] pstate: 20000145
....
=========

Fix this by bailing out early of kvm_timer_flush_hwstate() if we don't
have a VGIC at all.

Reported-by: Cosmin Gorgovan <cosmin@linux-geek.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <stable@vger.kernel.org> # 4.4.x
2016-02-08 15:23:39 +00:00
..
arm KVM: arm/arm64: Fix reference to uninitialised VGIC 2016-02-08 15:23:39 +00:00
Kconfig KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configs 2015-11-04 16:24:30 +01:00
async_pf.c KVM-async_pf: Delete an unnecessary check before the function call "kmem_cache_destroy" 2015-11-25 17:24:23 +01:00
async_pf.h KVM: fix checkpatch.pl errors in kvm/async_pf.h 2015-06-19 17:16:25 +02:00
coalesced_mmio.c KVM: move iodev.h from virt/kvm/ to include/kvm 2015-03-26 21:43:12 +00:00
coalesced_mmio.h KVM: make the declaration of functions within 80 characters 2015-09-14 18:43:19 +02:00
eventfd.c KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomic 2015-11-04 16:24:35 +01:00
irqchip.c kvm/irqchip: kvm_arch_irq_routing_update renaming split 2015-11-25 17:24:21 +01:00
kvm_main.c kvm: rename pfn_t to kvm_pfn_t 2016-01-15 17:56:32 -08:00
vfio.c KVM: count number of assigned devices 2015-07-10 13:25:26 +02:00
vfio.h kvm: vfio: fix unregister kvm_device_ops of vfio 2014-10-24 13:30:47 +02:00