linux-kernel - [PATCH 4.2.y-ckt 37/98] arm/arm64: KVM: Fix ioctl error handling

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

Message-Id: <1458084692-23100-38-git-send-email-kamal@canonical.com>
Date:	Tue, 15 Mar 2016 16:30:31 -0700
From:	Kamal Mostafa <kamal@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	"Michael S . Tsirkin" <mst@...hat.com>,
	Marc Zyngier <marc.zyngier@....com>,
	Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 4.2.y-ckt 37/98] arm/arm64: KVM: Fix ioctl error handling

4.2.8-ckt6 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: "Michael S. Tsirkin" <mst@...hat.com>

commit 4cad67fca3fc952d6f2ed9e799621f07666a560f upstream.

Calling return copy_to_user(...) in an ioctl will not
do the right thing if there's a pagefault:
copy_to_user returns the number of bytes not copied
in this case.

Fix up kvm to do
	return copy_to_user(...)) ?  -EFAULT : 0;

everywhere.

Acked-by: Christoffer Dall <christoffer.dall@...aro.org>
Signed-off-by: Michael S. Tsirkin <mst@...hat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@....com>
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
 arch/arm/kvm/guest.c   | 2 +-
 arch/arm64/kvm/guest.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
index d503fbb..88993cc 100644
--- a/arch/arm/kvm/guest.c
+++ b/arch/arm/kvm/guest.c
@@ -155,7 +155,7 @@ static int get_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	u64 val;
 
 	val = kvm_arm_timer_get_reg(vcpu, reg->id);
-	return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id));
+	return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)) ? -EFAULT : 0;
 }
 
 static unsigned long num_core_regs(void)
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 9535bd5..d4e04d2 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -184,7 +184,7 @@ static int get_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	u64 val;
 
 	val = kvm_arm_timer_get_reg(vcpu, reg->id);
-	return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id));
+	return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)) ? -EFAULT : 0;
 }
 
 /**
-- 
2.7.0