linux-kernel - [PATCH 4.2 093/124] KVM: s390: avoid memory overwrites on emergency signal injection

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: <20151207144924.297039947@linuxfoundation.org>
Date:	Mon,  7 Dec 2015 09:56:23 -0500
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org, Dominik Dingel <dingel@...ux.vnet.ibm.com>,
	David Hildenbrand <dahi@...ux.vnet.ibm.com>,
	Christian Borntraeger <borntraeger@...ibm.com>
Subject: [PATCH 4.2 093/124] KVM: s390: avoid memory overwrites on emergency signal injection

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

------------------

From: David Hildenbrand <dahi@...ux.vnet.ibm.com>

commit b85de33a1a3433487b6a721cfdce25ec8673e622 upstream.

Commit 383d0b050106 ("KVM: s390: handle pending local interrupts via
bitmap") introduced a possible memory overwrite from user space.

User space could pass an invalid emergency signal code (sending VCPU)
and therefore exceed the bitmap. Let's take care of this case and
check that the id is in the valid range.

Reviewed-by: Dominik Dingel <dingel@...ux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <dahi@...ux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@...ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 arch/s390/kvm/interrupt.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -1130,6 +1130,10 @@ static int __inject_sigp_emergency(struc
 	trace_kvm_s390_inject_vcpu(vcpu->vcpu_id, KVM_S390_INT_EMERGENCY,
 				   irq->u.emerg.code, 0, 2);
 
+	/* sending vcpu invalid */
+	if (kvm_get_vcpu_by_id(vcpu->kvm, irq->u.emerg.code) == NULL)
+		return -EINVAL;
+
 	set_bit(irq->u.emerg.code, li->sigp_emerg_pending);
 	set_bit(IRQ_PEND_EXT_EMERGENCY, &li->pending_irqs);
 	atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/