linux-kernel - [PATCH][next] KVM: x86/mmu: Fix uninitialized boolean variable flush

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210622150912.23429-1-colin.king@canonical.com>
Date:   Tue, 22 Jun 2021 16:09:12 +0100
From:   Colin King <colin.king@...onical.com>
To:     Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        x86@...nel.org, "H . Peter Anvin" <hpa@...or.com>,
        Ben Gardon <bgardon@...gle.com>, kvm@...r.kernel.org
Cc:     kernel-janitors@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH][next] KVM: x86/mmu: Fix uninitialized boolean variable flush

From: Colin Ian King <colin.king@...onical.com>

In the case where kvm_memslots_have_rmaps(kvm) is false the boolean
variable flush is not set and is uninitialized.  If is_tdp_mmu_enabled(kvm)
is true then the call to kvm_tdp_mmu_zap_collapsible_sptes passes the
uninitialized value of flush into the call. Fix this by initializing
flush to false.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: e2209710ccc5 ("KVM: x86/mmu: Skip rmap operations if rmaps not allocated")
Signed-off-by: Colin Ian King <colin.king@...onical.com>
---
 arch/x86/kvm/mmu/mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index ed24e97c1549..b8d20f139729 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5689,7 +5689,7 @@ void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm,
 {
 	/* FIXME: const-ify all uses of struct kvm_memory_slot.  */
 	struct kvm_memory_slot *slot = (struct kvm_memory_slot *)memslot;
-	bool flush;
+	bool flush = false;
 
 	if (kvm_memslots_have_rmaps(kvm)) {
 		write_lock(&kvm->mmu_lock);
-- 
2.31.1