mshv_vtl: bounds-check cpu index in vtl mmap fault handler

cpu is taken from pgoff & 0xffff.  cpu_online() does not reject cpu >=
nr_cpu_ids, and per_cpu_ptr() can then walk off __per_cpu_offset.

Signed-off-by: Yi Xie <xieyi@kylinos.cn>
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
This commit is contained in:
Yi Xie
2026-07-09 10:19:47 +08:00
committed by Wei Liu
parent 72e3b0311a
commit 22dfdc17ce

View File

@@ -802,7 +802,7 @@ static vm_fault_t mshv_vtl_fault(struct vm_fault *vmf)
int cpu = vmf->pgoff & MSHV_PG_OFF_CPU_MASK;
int real_off = vmf->pgoff >> MSHV_REAL_OFF_SHIFT;
if (!cpu_online(cpu))
if (cpu >= nr_cpu_ids || !cpu_online(cpu))
return VM_FAULT_SIGBUS;
/*
* CPU Hotplug is not supported in VTL2 in OpenHCL, where this kernel driver exists.