From: Edward Cree <ecree.xilinx@gmail.com>
Date: Mon, 21 Aug 2023 19:01:53 +0100
Subject: sfc: allocate a big enough SKB for loopback selftest packet
Patch-mainline: v6.5
Git-commit: 6dc5774deefe38d9ab385a5dafbe6614ae63d166
References: jsc#PED-6894
Cited commits passed a size to alloc_skb that was only big enough for
the actual packet contents, but the following skb_put + memcpy writes
the whole struct efx_loopback_payload including leading and trailing
padding bytes (which are then stripped off with skb_pull/skb_trim).
This could cause an skb_over_panic, although in practice we get saved
by kmalloc_size_roundup.
Pass the entire size we use, instead of the size of the final packet.
Reported-by: Andy Moreton <andy.moreton@amd.com>
Fixes: cf60ed469629 ("sfc: use padding to fix alignment in loopback test")
Fixes: 30c24dd87f3f ("sfc: siena: use padding to fix alignment in loopback test")
Fixes: 1186c6b31ee1 ("sfc: falcon: use padding to fix alignment in loopback test")
Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230821180153.18652-1-edward.cree@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/sfc/falcon/selftest.c | 2 +-
drivers/net/ethernet/sfc/selftest.c | 2 +-
drivers/net/ethernet/sfc/siena/selftest.c | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/net/ethernet/sfc/falcon/selftest.c
+++ b/drivers/net/ethernet/sfc/falcon/selftest.c
@@ -428,7 +428,7 @@ static int ef4_begin_loopback(struct ef4
for (i = 0; i < state->packet_count; i++) {
/* Allocate an skb, holding an extra reference for
* transmit completion counting */
- skb = alloc_skb(EF4_LOOPBACK_PAYLOAD_LEN, GFP_KERNEL);
+ skb = alloc_skb(sizeof(state->payload), GFP_KERNEL);
if (!skb)
return -ENOMEM;
state->skbs[i] = skb;
--- a/drivers/net/ethernet/sfc/selftest.c
+++ b/drivers/net/ethernet/sfc/selftest.c
@@ -426,7 +426,7 @@ static int efx_begin_loopback(struct efx
for (i = 0; i < state->packet_count; i++) {
/* Allocate an skb, holding an extra reference for
* transmit completion counting */
- skb = alloc_skb(EFX_LOOPBACK_PAYLOAD_LEN, GFP_KERNEL);
+ skb = alloc_skb(sizeof(state->payload), GFP_KERNEL);
if (!skb)
return -ENOMEM;
state->skbs[i] = skb;
--- a/drivers/net/ethernet/sfc/siena/selftest.c
+++ b/drivers/net/ethernet/sfc/siena/selftest.c
@@ -426,7 +426,7 @@ static int efx_begin_loopback(struct efx
for (i = 0; i < state->packet_count; i++) {
/* Allocate an skb, holding an extra reference for
* transmit completion counting */
- skb = alloc_skb(EFX_LOOPBACK_PAYLOAD_LEN, GFP_KERNEL);
+ skb = alloc_skb(sizeof(state->payload), GFP_KERNEL);
if (!skb)
return -ENOMEM;
state->skbs[i] = skb;