From: Dan Carpenter <dan.carpenter@oracle.com> stable inclusion from stable-v5.10.88 commit 51f6302f81d243772047a74ffeceddfb11c964d5 bugzilla: 186058 https://gitee.com/openeuler/kernel/issues/I4QW6A Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 3ed21c1451a14d139e1ceb18f2fa70865ce3195a upstream. In this function "c->off" is a u32 and "size" is a long. On 64bit systems if "c->off" is greater than "size" then "size - c->off" is a negative and we always return -E2BIG. But on 32bit systems the subtraction is type promoted to a high positive u32 value and basically any "c->len" is accepted. Fixes: 4c8cf31885f6 ("vhost: introduce vDPA-based backend") Reported-by: Xie Yongji <xieyongji@bytedance.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/20211208103337.GA4047@kili Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- drivers/vhost/vdpa.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index fdeb20f2f174..e4d60009d908 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -196,7 +196,7 @@ static int vhost_vdpa_config_validate(struct vhost_vdpa *v, break; } - if (c->len == 0) + if (c->len == 0 || c->off > size) return -EINVAL; if (c->len > size - c->off) -- 2.20.1