linux-kernel - [PATCH 02/18] KVM: Fix overflow bug in overflow detection code

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: <11775793382198-git-send-email-avi@qumranet.com>
Date:	Thu, 26 Apr 2007 12:22:02 +0300
From:	Avi Kivity <avi@...ranet.com>
To:	kvm-devel@...ts.sourceforge.net
Cc:	linux-kernel@...r.kernel.org,
	Eric Sesterhenn / Snakebyte <snakebyte@....de>,
	Avi Kivity <avi@...ranet.com>
Subject: [PATCH 02/18] KVM: Fix overflow bug in overflow detection code

From: Eric Sesterhenn / Snakebyte <snakebyte@....de>

The expression

   sp - 6 < sp

where sp is a u16 is undefined in C since 'sp - 6' is promoted to int,
and signed overflow is undefined in C.  gcc 4.2 actually warns about it.
Replace with a simpler test.

Signed-off-by: Eric Sesterhenn <snakebyte@....de>
Signed-off-by: Avi Kivity <avi@...ranet.com>
---
 drivers/kvm/vmx.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 61a6116..8c0115b 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1182,7 +1182,7 @@ static void inject_rmode_irq(struct kvm_vcpu *vcpu, int irq)
 	u16 sp =  vmcs_readl(GUEST_RSP);
 	u32 ss_limit = vmcs_read32(GUEST_SS_LIMIT);
 
-	if (sp > ss_limit || sp - 6 > sp) {
+	if (sp > ss_limit || sp < 6 ) {
 		vcpu_printf(vcpu, "%s: #SS, rsp 0x%lx ss 0x%lx limit 0x%x\n",
 			    __FUNCTION__,
 			    vmcs_readl(GUEST_RSP),
-- 
1.5.0.6

-
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/