[Intel-wired-lan] [PATCH] ice: Fix improper handling of refcount in ice_sriov_set_msix_vec_count()

[Gui-Dong Han]

This patch addresses an issue with improper reference count handling in the
ice_sriov_set_msix_vec_count() function. Specifically, the function calls
ice_get_vf_by_id(), which increments the reference count of the vf pointer.
If the subsequent call to ice_get_vf_vsi() fails, the function currently
returns an error without decrementing the reference count of the vf
pointer, leading to a reference count leak.

The correct behavior, as implemented in this patch, is to decrement the
reference count using ice_put_vf(vf) before returning an error when vsi
is NULL.
 
This bug was identified by an experimental static analysis tool developed
by our team. The tool specializes in analyzing reference count operations
and identifying potential mismanagement of reference counts. In this case,
the tool flagged the missing decrement operation as a potential issue,
leading to this patch.

Fixes: 4035c72dc1ba ("ice: reconfig host after changing MSI-X on VF")
Cc: stable at vger.kernel.org
Signed-off-by: Gui-Dong Han <hanguidong02 at outlook.com>
---
 drivers/net/ethernet/intel/ice/ice_sriov.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_sriov.c b/drivers/net/ethernet/intel/ice/ice_sriov.c
index 55ef33208456..eb5030aba9a5 100644
--- a/drivers/net/ethernet/intel/ice/ice_sriov.c
+++ b/drivers/net/ethernet/intel/ice/ice_sriov.c
@@ -1096,8 +1096,10 @@ int ice_sriov_set_msix_vec_count(struct pci_dev *vf_dev, int msix_vec_count)
 		return -ENOENT;
 
 	vsi = ice_get_vf_vsi(vf);
-	if (!vsi)
+	if (!vsi) {
+		ice_put_vf(vf);
 		return -ENOENT;
+	}
 
 	prev_msix = vf->num_msix;
 	prev_queues = vf->num_vf_qs;
-- 
2.25.1