From 61deee962896f7eb547adc66ef09c8f1e7ddf7d7 Mon Sep 17 00:00:00 2001 From: Bert Kenward Date: Tue, 15 Aug 2017 14:55:32 +0100 Subject: [PATCH] sfc: don't try and read ef10 data on non-ef10 NIC The MAC stats command takes a port ID, which doesn't exist on pre-ef10 NICs (5000- and 6000- series). This is extracted from the NIC specific data; we misinterpret this as the ef10 data structure, causing us to read potentially unallocated data. With a KASAN kernel this can cause errors with: BUG: KASAN: slab-out-of-bounds in efx_mcdi_mac_stats Fixes: 0a2ab4d988d7 ("sfc: set the port-id when calling MC_CMD_MAC_STATS") Reported-by: Stefano Brivio Tested-by: Stefano Brivio Signed-off-by: Bert Kenward Signed-off-by: David S. Miller --- drivers/net/ethernet/sfc/mcdi_port.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/sfc/mcdi_port.c b/drivers/net/ethernet/sfc/mcdi_port.c index c905971c5f3a..990a63d7fcb7 100644 --- a/drivers/net/ethernet/sfc/mcdi_port.c +++ b/drivers/net/ethernet/sfc/mcdi_port.c @@ -938,7 +938,6 @@ enum efx_stats_action { static int efx_mcdi_mac_stats(struct efx_nic *efx, enum efx_stats_action action, int clear) { - struct efx_ef10_nic_data *nic_data = efx->nic_data; MCDI_DECLARE_BUF(inbuf, MC_CMD_MAC_STATS_IN_LEN); int rc; int change = action == EFX_STATS_PULL ? 0 : 1; @@ -960,7 +959,12 @@ static int efx_mcdi_mac_stats(struct efx_nic *efx, MAC_STATS_IN_PERIODIC_NOEVENT, 1, MAC_STATS_IN_PERIOD_MS, period); MCDI_SET_DWORD(inbuf, MAC_STATS_IN_DMA_LEN, dma_len); - MCDI_SET_DWORD(inbuf, MAC_STATS_IN_PORT_ID, nic_data->vport_id); + + if (efx_nic_rev(efx) >= EFX_REV_HUNT_A0) { + struct efx_ef10_nic_data *nic_data = efx->nic_data; + + MCDI_SET_DWORD(inbuf, MAC_STATS_IN_PORT_ID, nic_data->vport_id); + } rc = efx_mcdi_rpc_quiet(efx, MC_CMD_MAC_STATS, inbuf, sizeof(inbuf), NULL, 0, NULL); -- 2.20.1