This is a note to let you know that I've just added the patch titled KVM: arm64: Force PTE mapping on fault resulting in a device mapping to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-arm64-force-pte-mapping-on-fault-resulting-in-a-.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 0a9202aa2e43c69b0f2e02a3363f64010361932b Author: Santosh Shukla <sashukla@xxxxxxxxxx> Date: Mon Oct 26 16:54:07 2020 +0530 KVM: arm64: Force PTE mapping on fault resulting in a device mapping [ Upstream commit 91a2c34b7d6fadc9c5d9433c620ea4c32ee7cae8 ] VFIO allows a device driver to resolve a fault by mapping a MMIO range. This can be subsequently result in user_mem_abort() to try and compute a huge mapping based on the MMIO pfn, which is a sure recipe for things to go wrong. Instead, force a PTE mapping when the pfn faulted in has a device mapping. Fixes: 6d674e28f642 ("KVM: arm/arm64: Properly handle faulting of device mappings") Suggested-by: Marc Zyngier <maz@xxxxxxxxxx> Signed-off-by: Santosh Shukla <sashukla@xxxxxxxxxx> [maz: rewritten commit message] Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/1603711447-11998-2-git-send-email-sashukla@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 8700402f3000d..03a586ab6d27b 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1756,6 +1756,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (kvm_is_device_pfn(pfn)) { mem_type = PAGE_S2_DEVICE; flags |= KVM_S2PTE_FLAG_IS_IOMAP; + force_pte = true; } else if (logging_active) { /* * Faults on pages in a memslot with logging enabled