[PATCH 5.15 004/177] KVM: downgrade two BUG_ONs to WARN_ON_ONCE

Greg Kroah-Hartman
2021-12-20T14:56:45Z

From: Paolo Bonzini <pbonzini@redhat.com>

[ 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>
---
virt/kvm/kvm_main.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index ce1847bc898b2..c6bfd4e15d28a 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3001,7 +3001,8 @@ 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))
@@ -3038,7 +3039,8 @@ 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))
--
2.33.0