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[dpdk-dev] i40e: unintended sign extension

Message ID 1463749416-7658-1-git-send-email-slawomirx.mrozowicz@intel.com (mailing list archive)
State Accepted, archived
Delegated to: Bruce Richardson
Headers

Commit Message

Slawomir Mrozowicz May 20, 2016, 1:03 p.m. UTC 
  Suspicious implicit sign extension: pf->fdir.match_counter_index
with type unsigned short (16 bits, unsigned) is promoted in
pf->fdir.match_counter_index << 20 to type int (32 bits, signed),
then sign-extended to type unsigned long (64 bits, unsigned).
If pf->fdir.match_counter_index << 20 is greater than 0x7FFFFFFF,
the upper bits of the result will all be 1.
To fix the issue set explicit cast uint32_t of pf->fdir.match_counter_index.

Fixes: 05999aab4ca6 ("i40e: add or delete flow director")
Coverity ID 13315

Signed-off-by: Slawomir Mrozowicz <slawomirx.mrozowicz@intel.com>
---
 drivers/net/i40e/i40e_fdir.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Bruce Richardson June 9, 2016, 3:14 p.m. UTC | #1 
On Fri, May 20, 2016 at 03:03:36PM +0200, Slawomir Mrozowicz wrote:
> Suspicious implicit sign extension: pf->fdir.match_counter_index
> with type unsigned short (16 bits, unsigned) is promoted in
> pf->fdir.match_counter_index << 20 to type int (32 bits, signed),
> then sign-extended to type unsigned long (64 bits, unsigned).
> If pf->fdir.match_counter_index << 20 is greater than 0x7FFFFFFF,
> the upper bits of the result will all be 1.
> To fix the issue set explicit cast uint32_t of pf->fdir.match_counter_index.
> 
> Fixes: 05999aab4ca6 ("i40e: add or delete flow director")
> Coverity ID 13315
> 
> Signed-off-by: Slawomir Mrozowicz <slawomirx.mrozowicz@intel.com>

Acked-by: Bruce Richardson <bruce.richardson@intel.com>

Applied to dpdk-next-net/rel_16_07

/Bruce
diff mbox

Patch

diff --git a/drivers/net/i40e/i40e_fdir.c b/drivers/net/i40e/i40e_fdir.c
index 8aa41e5..66ef83f 100644
--- a/drivers/net/i40e/i40e_fdir.c
+++ b/drivers/net/i40e/i40e_fdir.c
@@ -1141,7 +1141,8 @@  i40e_fdir_filter_programming(struct i40e_pf *pf,
 	fdirdp->dtype_cmd_cntindex |=
 			rte_cpu_to_le_32(I40E_TXD_FLTR_QW1_CNT_ENA_MASK);
 	fdirdp->dtype_cmd_cntindex |=
-			rte_cpu_to_le_32((pf->fdir.match_counter_index <<
+			rte_cpu_to_le_32(
+			((uint32_t)pf->fdir.match_counter_index <<
 			I40E_TXD_FLTR_QW1_CNTINDEX_SHIFT) &
 			I40E_TXD_FLTR_QW1_CNTINDEX_MASK);