octeontx2-pf: Fix unintentional sign extension issue

The shifting of the u16 result from ntohs(proto) by 16 bits to the
left will be promoted to a 32 bit signed int and then sign-extended
to a u64.  In the event that the top bit of the return from ntohs(proto)
is set then all then all the upper 32 bits of a 64 bit long end up as
also being set because of the sign-extension. Fix this by casting to
a u64 long before the shift.

Addresses-Coverity: ("Unintended sign extension")
Fixes: f0c2982aaf98 ("octeontx2-pf: Add support for SR-IOV management function")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20201118130520.460365-1-colin.king@canonical.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
index 4c82f60f3cf3baeafbfc35fee669580f5b7d2553..634d60655a74a3ce2341f473bcb519121174dd7d 100644 (file)
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
@@ -2084,7 +2084,7 @@ static int otx2_do_set_vf_vlan(struct otx2_nic *pf, int vf, u16 vlan, u8 qos,
        vtag_req->vtag_size = VTAGSIZE_T4;
        vtag_req->cfg_type = 0; /* tx vlan cfg */
        vtag_req->tx.cfg_vtag0 = 1;
-       vtag_req->tx.vtag0 = (ntohs(proto) << 16) | vlan;
+       vtag_req->tx.vtag0 = ((u64)ntohs(proto) << 16) | vlan;
 
        err = otx2_sync_mbox_msg(&pf->mbox);
        if (err)