Messages in this thread | | | Subject | Re: [PATCH 2/3] KVM: Check validity of offset+length of gfn_to_pfn_cache prior to activation | From | David Woodhouse <> | Date | Wed, 20 Mar 2024 08:20:44 +0000 |
| |
On Tue, 2024-03-19 at 17:15 -0700, Sean Christopherson wrote: > When activating a gfn_to_pfn_cache, verify that the offset+length is sane > and usable before marking the cache active. Letting __kvm_gpc_refresh() > detect the problem results in a cache being marked active without setting > the GPA (or any other fields), which in turn results in KVM trying to > refresh a cache with INVALID_GPA. > > Attempting to refresh a cache with INVALID_GPA isn't functionally > problematic, but it runs afoul of the sanity check that exactly one of > GPA or userspace HVA is valid, i.e. that a cache is either GPA-based or > HVA-based. > > Reported-by: syzbot+106a4f72b0474e1d1b33@syzkaller.appspotmail.com > Closes: https://lore.kernel.org/all/0000000000005fa5cc0613f1cebd@google.com > Fixes: 721f5b0dda78 ("KVM: pfncache: allow a cache to be activated with a fixed (userspace) HVA")
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
[unhandled content-type:application/pkcs7-signature] | |