sfc: allocate a big enough SKB for loopback selftest packet

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: cf60ed4696 ("sfc: use padding to fix alignment in loopback test")
Fixes: 30c24dd87f ("sfc: siena: use padding to fix alignment in loopback test")
Fixes: 1186c6b31e ("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>
This commit is contained in:
Edward Cree 2023-08-21 19:01:53 +01:00 committed by Jakub Kicinski
parent 1a8660546b
commit 6dc5774dee
3 changed files with 3 additions and 3 deletions

View file

@ -428,7 +428,7 @@ static int ef4_begin_loopback(struct ef4_tx_queue *tx_queue)
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;

View file

@ -426,7 +426,7 @@ static int efx_begin_loopback(struct efx_tx_queue *tx_queue)
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;

View file

@ -426,7 +426,7 @@ static int efx_begin_loopback(struct efx_tx_queue *tx_queue)
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;