From b7c23d30eeb287801113c66e10c0d79387ee02e1 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Wed, 4 Feb 2015 15:59:11 +0100 Subject: [PATCH] KVM: s390: reinjection of irqs can fail in the tpi handler [ Upstream commit 15462e37ca848abac7477dece65f8af25febd744 ] The reinjection of an I/O interrupt can fail if the list is at the limit and between the dequeue and the reinjection, another I/O interrupt is injected (e.g. if user space floods kvm with I/O interrupts). This patch avoids this memory leak and returns -EFAULT in this special case. This error is not recoverable, so let's fail hard. This can later be avoided by not dequeuing the interrupt but working directly on the locked list. Signed-off-by: David Hildenbrand Cc: stable@vger.kernel.org # 3.16+ Signed-off-by: Christian Borntraeger Signed-off-by: Sasha Levin --- arch/s390/kvm/interrupt.c | 4 ++-- arch/s390/kvm/kvm-s390.h | 4 ++-- arch/s390/kvm/priv.c | 5 ++++- 3 files changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 29e2e5aa21116..da92802a523bd 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -930,10 +930,10 @@ int kvm_s390_inject_vm(struct kvm *kvm, return rc; } -void kvm_s390_reinject_io_int(struct kvm *kvm, +int kvm_s390_reinject_io_int(struct kvm *kvm, struct kvm_s390_interrupt_info *inti) { - __inject_vm(kvm, inti); + return __inject_vm(kvm, inti); } int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu, diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index 244d023031828..4c173474ecfeb 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -148,8 +148,8 @@ int __must_check kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu, int __must_check kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code); struct kvm_s390_interrupt_info *kvm_s390_get_io_int(struct kvm *kvm, u64 cr6, u64 schid); -void kvm_s390_reinject_io_int(struct kvm *kvm, - struct kvm_s390_interrupt_info *inti); +int kvm_s390_reinject_io_int(struct kvm *kvm, + struct kvm_s390_interrupt_info *inti); int kvm_s390_mask_adapter(struct kvm *kvm, unsigned int id, bool masked); /* implemented in priv.c */ diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 84c3d7fada7c9..69cd0ce84b1ed 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -278,7 +278,10 @@ reinject_interrupt: * instruction is suppressed from the guest's view: reinject the * interrupt. */ - kvm_s390_reinject_io_int(vcpu->kvm, inti); + if (kvm_s390_reinject_io_int(vcpu->kvm, inti)) { + kfree(inti); + rc = -EFAULT; + } /* don't set the cc, a pgm irq was injected or we drop to user space */ return rc ? -EFAULT : 0; } -- 2.47.3