From: Tao Cui The destroy callbacks of the four irqchip devices free the device structure without clearing kvm->arch.{ipi,eiointc,pch_pic,dmsintc}, leaving a dangling pointer. ops->destroy() is not only called at VM teardown but also when KVM_CREATE_DEVICE succeeds and the following anon_inode_getfd() fails (e.g. under RLIMIT_NOFILE); the VM stays alive, kvm_arch_irqchip_in_kernel() still reports true, and interrupt injection dereferences the freed device. Clear the pointer before freeing. Fixes: c532de5a67a7 ("LoongArch: KVM: Add IPI device support") Fixes: 2e8b9df82631 ("LoongArch: KVM: Add EIOINTC device support") Fixes: e785dfacf7e7 ("LoongArch: KVM: Add PCHPIC device support") Fixes: 229132c309d6 ("LoongArch: KVM: Add DMSINTC device support") Signed-off-by: Tao Cui --- arch/loongarch/kvm/intc/dmsintc.c | 5 ++++- arch/loongarch/kvm/intc/eiointc.c | 1 + arch/loongarch/kvm/intc/ipi.c | 1 + arch/loongarch/kvm/intc/pch_pic.c | 1 + 4 files changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/loongarch/kvm/intc/dmsintc.c b/arch/loongarch/kvm/intc/dmsintc.c index 89f980d867be..63072595c01b 100644 --- a/arch/loongarch/kvm/intc/dmsintc.c +++ b/arch/loongarch/kvm/intc/dmsintc.c @@ -161,11 +161,14 @@ static int kvm_dmsintc_create(struct kvm_device *dev, u32 type) static void kvm_dmsintc_destroy(struct kvm_device *dev) { + struct loongarch_dmsintc *s; if (!dev || !dev->kvm || !dev->kvm->arch.dmsintc) return; - kfree(dev->kvm->arch.dmsintc); + s = dev->kvm->arch.dmsintc; + dev->kvm->arch.dmsintc = NULL; + kfree(s); kfree(dev); } diff --git a/arch/loongarch/kvm/intc/eiointc.c b/arch/loongarch/kvm/intc/eiointc.c index 80f78e07c74a..fe0a1918f26f 100644 --- a/arch/loongarch/kvm/intc/eiointc.c +++ b/arch/loongarch/kvm/intc/eiointc.c @@ -675,6 +675,7 @@ static void kvm_eiointc_destroy(struct kvm_device *dev) kvm = dev->kvm; eiointc = kvm->arch.eiointc; + kvm->arch.eiointc = NULL; mutex_lock(&kvm->slots_lock); kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &eiointc->device); kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &eiointc->device_vext); diff --git a/arch/loongarch/kvm/intc/ipi.c b/arch/loongarch/kvm/intc/ipi.c index 7b333a4a0430..6ee90c10827a 100644 --- a/arch/loongarch/kvm/intc/ipi.c +++ b/arch/loongarch/kvm/intc/ipi.c @@ -444,6 +444,7 @@ static void kvm_ipi_destroy(struct kvm_device *dev) kvm = dev->kvm; ipi = kvm->arch.ipi; + kvm->arch.ipi = NULL; mutex_lock(&kvm->slots_lock); kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &ipi->device); mutex_unlock(&kvm->slots_lock); diff --git a/arch/loongarch/kvm/intc/pch_pic.c b/arch/loongarch/kvm/intc/pch_pic.c index 2b63b0c2c7ce..62c09b5f3937 100644 --- a/arch/loongarch/kvm/intc/pch_pic.c +++ b/arch/loongarch/kvm/intc/pch_pic.c @@ -483,6 +483,7 @@ static void kvm_pch_pic_destroy(struct kvm_device *dev) kvm = dev->kvm; s = kvm->arch.pch_pic; + kvm->arch.pch_pic = NULL; /* unregister pch pic device and free it's memory */ mutex_lock(&kvm->slots_lock); kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &s->device); -- 2.43.0