[next,S80-V3,09/11] i40e: add check for return from find_first_bit call

Message ID 20170907120556.45699-9-alice.michael@intel.com
State Under Review
Delegated to: Jeff Kirsher
Headers show
Series
  • [next,S80-V3,01/11] i40e: use the safe hash table iterator when deleting mac filters
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Commit Message

Alice Michael Sept. 7, 2017, 12:05 p.m.
From: Lihong Yang <lihong.yang@intel.com>

The find_first_bit function will return the size passed to search
if the first set bit is not found. This patch adds the check in case
that happens as the return value would be used as the index in an array
and that would have caused the out-of-bounds access.

Detected by CoverityScan, CID 1295969 Out-of-bounds access

Signed-off-by: Lihong Yang <lihong.yang@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Bowers, AndrewX Sept. 12, 2017, 9:48 p.m. | #1
> -----Original Message-----
> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On
> Behalf Of Alice Michael
> Sent: Thursday, September 7, 2017 5:06 AM
> To: Michael, Alice <alice.michael@intel.com>; intel-wired-
> lan@lists.osuosl.org
> Subject: [Intel-wired-lan] [next PATCH S80-V3 09/11] i40e: add check for
> return from find_first_bit call
> 
> From: Lihong Yang <lihong.yang@intel.com>
> 
> The find_first_bit function will return the size passed to search if the first set
> bit is not found. This patch adds the check in case that happens as the return
> value would be used as the index in an array and that would have caused the
> out-of-bounds access.
> 
> Detected by CoverityScan, CID 1295969 Out-of-bounds access
> 
> Signed-off-by: Lihong Yang <lihong.yang@intel.com>
> ---
>  drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 4 ++++
>  1 file changed, 4 insertions(+)

Tested-by: Andrew Bowers <andrewx.bowers@intel.com>

Patch

diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index 7dc042b..b2bdf27 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -306,6 +306,10 @@  static void i40e_config_irq_link_list(struct i40e_vf *vf, u16 vsi_id,
 	next_q = find_first_bit(&linklistmap,
 				(I40E_MAX_VSI_QP *
 				 I40E_VIRTCHNL_SUPPORTED_QTYPES));
+	if (unlikely(next_q == (I40E_MAX_VSI_QP *
+				I40E_VIRTCHNL_SUPPORTED_QTYPES)))
+		goto irq_list_done;
+
 	vsi_queue_id = next_q / I40E_VIRTCHNL_SUPPORTED_QTYPES;
 	qtype = next_q % I40E_VIRTCHNL_SUPPORTED_QTYPES;
 	pf_queue_id = i40e_vc_get_pf_queue_id(vf, vsi_id, vsi_queue_id);