From 15462e37ca848abac7477dece65f8af25febd744 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 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 --- 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 073b5f387d1d..e7a46e817874 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -1332,10 +1332,10 @@ 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 s390int_to_s390irq(struct kvm_s390_interrupt *s390int, diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index c34109aa552d..6995a3080a0e 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -151,8 +151,8 @@ 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 intercept.c */ diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index be7138e84351..b982fbca34df 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -279,7 +279,10 @@ 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; }