[PATCH 4.14 116/159] i40e: use the safe hash table iterator when deleting mac filters

Greg Kroah-Hartman
2017-12-22T09:23:59Z

From: Lihong Yang <lihong.yang@intel.com>

[ Upstream commit 784548c40d6f43eff2297220ad7800dc04be03c6 ]

This patch replaces hash_for_each function with hash_for_each_safe
when calling __i40e_del_filter. The hash_for_each_safe function is
the right one to use when iterating over a hash table to safely remove
a hash entry. Otherwise, incorrect values may be read from freed memory.

Detected by CoverityScan, CID 1402048 Read from pointer after free

Signed-off-by: Lihong Yang <lihong.yang@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -2779,6 +2779,7 @@ int i40e_ndo_set_vf_mac(struct net_devic
struct i40e_mac_filter *f;
struct i40e_vf *vf;
int ret = 0;
+ struct hlist_node *h;
int bkt;

/* validate the request */
@@ -2817,7 +2818,7 @@ int i40e_ndo_set_vf_mac(struct net_devic
/* Delete all the filters for this VSI - we're going to kill it
* anyway.
*/
- hash_for_each(vsi->mac_filter_hash, bkt, f, hlist)
+ hash_for_each_safe(vsi->mac_filter_hash, bkt, h, f, hlist)
__i40e_del_filter(vsi, f);

spin_unlock_bh(&vsi->mac_filter_hash_lock);