IB/hfi1: Reject a zero-length user expected buffer

A zero length user buffer makes no sense and the code
does not handle it correctly.  Instead, reject a
zero length as invalid.

Fixes: 97736f36dbeb ("IB/hfi1: Validate page aligned for a given virtual addres")
Signed-off-by: Dean Luick <dean.luick@cornelisnetworks.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Link: https://lore.kernel.org/r/167328547120.1472310.6362802432127399257.stgit@awfm-02.cornelisnetworks.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

diff --git a/drivers/infiniband/hw/hfi1/user_exp_rcv.c b/drivers/infiniband/hw/hfi1/user_exp_rcv.c
index 186d3029126069b9f3184dc055831d5937e80429..3c609b11e71ca22b0f4d4c91650d2ed92f3197a1 100644 (file)
--- a/drivers/infiniband/hw/hfi1/user_exp_rcv.c
+++ b/drivers/infiniband/hw/hfi1/user_exp_rcv.c
@@ -256,6 +256,8 @@ int hfi1_user_exp_rcv_setup(struct hfi1_filedata *fd,
 
        if (!PAGE_ALIGNED(tinfo->vaddr))
                return -EINVAL;
+       if (tinfo->length == 0)
+               return -EINVAL;
 
        tidbuf = kzalloc(sizeof(*tidbuf), GFP_KERNEL);
        if (!tidbuf)