From 6dc5774deefe38d9ab385a5dafbe6614ae63d166 Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Mon, 21 Aug 2023 19:01:53 +0100 Subject: 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 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 Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230821180153.18652-1-edward.cree@amd.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/sfc/falcon/selftest.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/ethernet/sfc/falcon/selftest.c') diff --git a/drivers/net/ethernet/sfc/falcon/selftest.c b/drivers/net/ethernet/sfc/falcon/selftest.c index cf1d67b6d86d..c3dc88e6c26c 100644 --- 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_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; -- cgit