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=...
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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)