From a41654c3ed1d7d6a2f7ae485f3e3c655b428f38f Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Thu, 19 Oct 2023 10:32:27 -0700 Subject: ixgbe: fix end of loop test in ixgbe_set_vf_macvlan() The list iterator in a list_for_each_entry() loop can never be NULL. If the loop exits without hitting a break then the iterator points to an offset off the list head and dereferencing it is an out of bounds access. Before we transitioned to using list_for_each_entry() loops, then it was possible for "entry" to be NULL and the comments mention this. I have updated the comments to match the new code. Fixes: c1fec890458a ("ethernet/intel: Use list_for_each_entry() helper") Signed-off-by: Dan Carpenter Reviewed-by: Simon Horman Reviewed-by: Jesse Brandeburg Tested-by: Rafal Romanowski Signed-off-by: Jacob Keller Signed-off-by: David S. Miller --- drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) (limited to 'drivers') diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c index cd593f5719e1..9cfdfa8a4355 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c @@ -640,6 +640,7 @@ static int ixgbe_set_vf_macvlan(struct ixgbe_adapter *adapter, int vf, int index, unsigned char *mac_addr) { struct vf_macvlans *entry; + bool found = false; int retval = 0; if (index <= 1) { @@ -661,22 +662,22 @@ static int ixgbe_set_vf_macvlan(struct ixgbe_adapter *adapter, if (!index) return 0; - entry = NULL; - list_for_each_entry(entry, &adapter->vf_mvs.l, l) { - if (entry->free) + if (entry->free) { + found = true; break; + } } /* * If we traversed the entire list and didn't find a free entry - * then we're out of space on the RAR table. Also entry may - * be NULL because the original memory allocation for the list - * failed, which is not fatal but does mean we can't support - * VF requests for MACVLAN because we couldn't allocate - * memory for the list management required. + * then we're out of space on the RAR table. It's also possible + * for the &adapter->vf_mvs.l list to be empty because the original + * memory allocation for the list failed, which is not fatal but does + * mean we can't support VF requests for MACVLAN because we couldn't + * allocate memory for the list management required. */ - if (!entry || !entry->free) + if (!found) return -ENOSPC; retval = ixgbe_add_mac_filter(adapter, mac_addr, vf); -- cgit v1.2.3