FAILED: patch "[PATCH] ice: Fix incorrect locking in ice_vc_process_vf_msg()" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From aaf461af729b81dbb19ec33abe6da74702b352d2 Mon Sep 17 00:00:00 2001
From: Ivan Vecera <ivecera@redhat.com>
Date: Fri, 1 Apr 2022 12:40:52 +0200
Subject: [PATCH] ice: Fix incorrect locking in ice_vc_process_vf_msg()

Usage of mutex_trylock() in ice_vc_process_vf_msg() is incorrect
because message sent from VF is ignored and never processed.

Use mutex_lock() instead to fix the issue. It is safe because this
mutex is used to prevent races between VF related NDOs and
handlers processing request messages from VF and these handlers
are running in ice_service_task() context. Additionally move this
mutex lock prior ice_vc_is_opcode_allowed() call to avoid potential
races during allowlist access.

Fixes: e6ba5273d4ed ("ice: Fix race conditions between virtchnl handling and VF ndo ops")
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/ice/ice_virtchnl.c b/drivers/net/ethernet/intel/ice/ice_virtchnl.c
index 69ff4b929772..5612c032f15a 100644
--- a/drivers/net/ethernet/intel/ice/ice_virtchnl.c
+++ b/drivers/net/ethernet/intel/ice/ice_virtchnl.c
@@ -3642,14 +3642,6 @@ void ice_vc_process_vf_msg(struct ice_pf *pf, struct ice_rq_event_info *event)
 			err = -EINVAL;
 	}
 
-	if (!ice_vc_is_opcode_allowed(vf, v_opcode)) {
-		ice_vc_send_msg_to_vf(vf, v_opcode,
-				      VIRTCHNL_STATUS_ERR_NOT_SUPPORTED, NULL,
-				      0);
-		ice_put_vf(vf);
-		return;
-	}
-
 error_handler:
 	if (err) {
 		ice_vc_send_msg_to_vf(vf, v_opcode, VIRTCHNL_STATUS_ERR_PARAM,
@@ -3660,12 +3652,13 @@ void ice_vc_process_vf_msg(struct ice_pf *pf, struct ice_rq_event_info *event)
 		return;
 	}
 
-	/* VF is being configured in another context that triggers a VFR, so no
-	 * need to process this message
-	 */
-	if (!mutex_trylock(&vf->cfg_lock)) {
-		dev_info(dev, "VF %u is being configured in another context that will trigger a VFR, so there is no need to handle this message\n",
-			 vf->vf_id);
+	mutex_lock(&vf->cfg_lock);
+
+	if (!ice_vc_is_opcode_allowed(vf, v_opcode)) {
+		ice_vc_send_msg_to_vf(vf, v_opcode,
+				      VIRTCHNL_STATUS_ERR_NOT_SUPPORTED, NULL,
+				      0);
+		mutex_unlock(&vf->cfg_lock);
 		ice_put_vf(vf);
 		return;
 	}