[PATCH v3 net 3/9] net: enetc: add ratelimiting to VF mailbox error messages

[Wei Fang]

Sashiko reported that a buggy or malicious guest VM can flood the host
kernel log by repeatedly sending VF-to-PF messages at a high rate,
degrading host performance and hiding important system logs [1].

Fix by replacing dev_err()/dev_warn() with dev_err_ratelimited(),
limiting output to the default kernel ratelimit. This ensures errors are
still logged for debugging while preventing log flooding attacks.

Link: https://sashiko.dev/#/patchset/20260511080805.2052495-1-wei.fang%40nxp.com #1
Fixes: beb74ac878c8 ("enetc: Add vf to pf messaging support")
Signed-off-by: Wei Fang <wei.fang@xxxxxxx>
Reviewed-by: Harshitha Ramamurthy <hramamurthy@xxxxxxxxxx>
---
 drivers/net/ethernet/freescale/enetc/enetc_pf.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf.c b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
index b743b6d33ccc..dea3a92c4722 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_pf.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
@@ -494,8 +494,9 @@ static u16 enetc_msg_pf_set_vf_primary_mac_addr(struct enetc_pf *pf,
 
 	addr = cmd->mac.sa_data;
 	if (vf_state->flags & ENETC_VF_FLAG_PF_SET_MAC) {
-		dev_warn(dev, "Attempt to override PF set mac addr for VF%d\n",
-			 vf_id);
+		dev_err_ratelimited(dev,
+				    "VF%d attempted to override PF set MAC\n",
+				    vf_id);
 		return ENETC_MSG_CMD_STATUS_FAIL;
 	}
 
@@ -520,8 +521,9 @@ void enetc_msg_handle_rxmsg(struct enetc_pf *pf, int vf_id, u16 *status)
 		break;
 	default:
 		*status = ENETC_MSG_CMD_STATUS_FAIL;
-		dev_err(dev, "command not supported (cmd_type: 0x%x)\n",
-			cmd_type);
+		dev_err_ratelimited(dev,
+				    "command not supported (cmd_type: 0x%x)\n",
+				    cmd_type);
 	}
 }
 
-- 
2.34.1