From patchwork Thu Feb 21 19:08:00 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [Oneiric/Precise/Quantal, CVE-2013-0311, 1/1] vhost: fix length for cross region descriptor Date: Thu, 21 Feb 2013 09:08:00 -0000 From: Luis Henriques X-Patchwork-Id: 222403 Message-Id: <1361473680-18720-1-git-send-email-luis.henriques@canonical.com> To: kernel-team@lists.ubuntu.com From: "Michael S. Tsirkin" CVE-2013-0311 BugLink: http://bugs.launchpad.net/bugs/1130951 If a single descriptor crosses a region, the second chunk length should be decremented by size translated so far, instead it includes the full descriptor length. Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: David S. Miller (cherry picked from commit bd97120fc3d1a11f3124c7c9ba1d91f51829eb85) Signed-off-by: Luis Henriques --- drivers/vhost/vhost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 61047fe..e3fac28 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -986,7 +986,7 @@ static int translate_desc(struct vhost_dev *dev, u64 addr, u32 len, } _iov = iov + ret; size = reg->memory_size - addr + reg->guest_phys_addr; - _iov->iov_len = min((u64)len, size); + _iov->iov_len = min((u64)len - s, size); _iov->iov_base = (void __user *)(unsigned long) (reg->userspace_addr + addr - reg->guest_phys_addr); s += size;