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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Sasha Levin <sashal@kernel.org>,
	kvm@vger.kernel.org
Subject: [PATCH MANUALSEL 5.10 4/4] KVM: downgrade two BUG_ONs to WARN_ON_ONCE
Date: Mon, 13 Dec 2021 09:20:18 -0500	[thread overview]
Message-ID: <20211213142020.352376-4-sashal@kernel.org> (raw)
In-Reply-To: <20211213142020.352376-1-sashal@kernel.org>

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 97ac3c6fd4441..4a7d377b3a500 100644
--- 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))
-- 
2.33.0


  parent reply	other threads:[~2021-12-13 14:20 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-13 14:20 [PATCH MANUALSEL 5.10 1/4] sched/cputime: Fix getrusage(RUSAGE_THREAD) with nohz_full Sasha Levin
2021-12-13 14:20 ` [PATCH MANUALSEL 5.10 2/4] KVM: VMX: clear vmx_x86_ops.sync_pir_to_irr if APICv is disabled Sasha Levin
2021-12-13 14:29   ` Paolo Bonzini
2021-12-13 14:20 ` [PATCH MANUALSEL 5.10 3/4] KVM: selftests: Make sure kvm_create_max_vcpus test won't hit RLIMIT_NOFILE Sasha Levin
2021-12-13 14:22   ` Paolo Bonzini
2021-12-13 14:20 ` Sasha Levin [this message]
2021-12-13 14:22   ` [PATCH MANUALSEL 5.10 4/4] KVM: downgrade two BUG_ONs to WARN_ON_ONCE Paolo Bonzini

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