The maximum supported cpu number is EIOINTC_ROUTE_MAX_VCPUS about irqchip eiointc, here add validation about cpu number to avoid array pointer overflow.

Cc: stable@vger.kernel.org Fixes: 1ad7efa552fd ("LoongArch: KVM: Add EIOINTC user mode read and write functions") Signed-off-by: Bibo Mao maobibo@loongson.cn --- arch/loongarch/kvm/intc/eiointc.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/arch/loongarch/kvm/intc/eiointc.c b/arch/loongarch/kvm/intc/eiointc.c index b48511f903b5..ed80bf290755 100644 --- a/arch/loongarch/kvm/intc/eiointc.c +++ b/arch/loongarch/kvm/intc/eiointc.c @@ -798,7 +798,7 @@ static int kvm_eiointc_ctrl_access(struct kvm_device *dev, int ret = 0; unsigned long flags; unsigned long type = (unsigned long)attr->attr; - u32 i, start_irq; + u32 i, start_irq, val; void __user *data; struct loongarch_eiointc *s = dev->kvm->arch.eiointc;

@@ -806,7 +806,12 @@ static int kvm_eiointc_ctrl_access(struct kvm_device *dev, spin_lock_irqsave(&s->lock, flags); switch (type) { case KVM_DEV_LOONGARCH_EXTIOI_CTRL_INIT_NUM_CPU: - if (copy_from_user(&s->num_cpu, data, 4)) + if (copy_from_user(&val, data, 4) == 0) { + if (val < EIOINTC_ROUTE_MAX_VCPUS) + s->num_cpu = val; + else + ret = -EINVAL; + } else ret = -EFAULT; break; case KVM_DEV_LOONGARCH_EXTIOI_CTRL_INIT_FEATURE: @@ -835,7 +840,7 @@ static int kvm_eiointc_regs_access(struct kvm_device *dev, struct kvm_device_attr *attr, bool is_write) { - int addr, cpuid, offset, ret = 0; + int addr, cpu, offset, ret = 0; unsigned long flags; void *p = NULL; void __user *data; @@ -843,7 +848,7 @@ static int kvm_eiointc_regs_access(struct kvm_device *dev,

s = dev->kvm->arch.eiointc; addr = attr->attr; - cpuid = addr >> 16; + cpu = addr >> 16; addr &= 0xffff; data = (void __user *)attr->addr; switch (addr) { @@ -868,8 +873,11 @@ static int kvm_eiointc_regs_access(struct kvm_device *dev, p = &s->isr.reg_u32[offset]; break; case EIOINTC_COREISR_START ... EIOINTC_COREISR_END: + if (cpu >= s->num_cpu) + return -EINVAL; + offset = (addr - EIOINTC_COREISR_START) / 4; - p = &s->coreisr.reg_u32[cpuid][offset]; + p = &s->coreisr.reg_u32[cpu][offset]; break; case EIOINTC_COREMAP_START ... EIOINTC_COREMAP_END: offset = (addr - EIOINTC_COREMAP_START) / 4;