[patch 1/2 -next] cxgb4: potential shift wrapping bug

Dan Carpenter
2014-10-02T10:20:53Z

"cntxt_id" is an unsigned int but "udb" is a u64 so there is a potential
shift wrapping bug here.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c b/drivers/net/ethernet/chelsio/cxgb4/sge.c
index bb7851e..e8e90ce 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c
@@ -2258,7 +2258,7 @@ static u64 udb_address(struct adapter *adap, unsigned int cntxt_id,
(QUEUESPERPAGEPF1 - QUEUESPERPAGEPF0) * adap->fn);
udb_density = 1 << ((qpp >> s_qpp) & QUEUESPERPAGEPF0_MASK);
qpshift = PAGE_SHIFT - ilog2(udb_density);
- udb = cntxt_id << qpshift;
+ udb = (u64)cntxt_id << qpshift;
udb &= PAGE_MASK;
page = udb / PAGE_SIZE;
udb += (cntxt_id - (page * udb_density)) * SGE_UDB_SIZE;