KVM: downgrade two BUG_ONs to WARN_ON_ONCE

[ Upstream commit 5f25e71e311478f9bb0a8ef49e7d8b95316491d7 ]

This is not an unrecoverable situation.  Users of kvm_read_guest_offset_cached
and kvm_write_guest_offset_cached must expect the read/write to fail, and
therefore it is possible to just return early with an error value.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 97ac3c6fd4441bc9598ba305536601bc5e1449bd..4a7d377b3a500b69aee71b535a4ad56c9ae45d41 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2590,7 +2590,8 @@ int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
        int r;
        gpa_t gpa = ghc->gpa + offset;
 
-       BUG_ON(len + offset > ghc->len);
+       if (WARN_ON_ONCE(len + offset > ghc->len))
+               return -EINVAL;
 
        if (slots->generation != ghc->generation) {
                if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len))
@@ -2627,7 +2628,8 @@ int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
        int r;
        gpa_t gpa = ghc->gpa + offset;
 
-       BUG_ON(len + offset > ghc->len);
+       if (WARN_ON_ONCE(len + offset > ghc->len))
+               return -EINVAL;
 
        if (slots->generation != ghc->generation) {
                if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len))