From b95f457bb7ba38f03a71b474e35f53670322f0db Mon Sep 17 00:00:00 2001 From: Camelia Groza Date: Mon, 15 Jan 2018 17:41:01 +0200 Subject: [PATCH] sdk_dpaa: update buffer recycling conditions Guarantee there is enough space inside the skb's headroom to store the skb back-pointer before recycling the buffer. The back-pointer is stored right before the buffer's start. Signed-off-by: Camelia Groza --- drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c +++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c @@ -350,7 +350,13 @@ bool dpa_buf_is_recyclable(struct sk_buf /* left align to the nearest cacheline */ new = (unsigned char *)((unsigned long)new & ~(SMP_CACHE_BYTES - 1)); - if (likely(new >= skb->head && + /* Make sure there is enough space to store the skb back-pointer in + * the headroom, right before the start of the buffer. + * + * Guarantee that both maximum size and maximum data offsets aren't + * crossed. + */ + if (likely(new >= (skb->head + sizeof(void *)) && new >= (skb->data - DPA_MAX_FD_OFFSET) && skb_end_pointer(skb) - new <= DPA_RECYCLE_MAX_SIZE)) { *new_buf_start = new;