Messages in this thread | | | Date | Wed, 16 Nov 2022 14:36:19 -0800 | From | Saeed Mahameed <> | Subject | Re: [PATCH net] net: nixge: fix potential memory leak in nixge_start_xmit() |
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On 15 Nov 21:20, Zhang Changzhong wrote: >On 2022/11/14 18:40, Francois Romieu wrote: >> Zhang Changzhong <zhangchangzhong@huawei.com> : >>> The nixge_start_xmit() returns NETDEV_TX_OK but does not free skb on two >>> error handling cases, which can lead to memory leak. >>> >>> To fix this, return NETDEV_TX_BUSY in case of nixge_check_tx_bd_space() >>> fails and add dev_kfree_skb_any() in case of dma_map_single() fails. >> >> This patch merge two unrelated changes. Please split. >> >>> Fixes: 492caffa8a1a ("net: ethernet: nixge: Add support for National Instruments XGE netdev") >>> Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com> >>> --- >>> drivers/net/ethernet/ni/nixge.c | 6 ++++-- >>> 1 file changed, 4 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/net/ethernet/ni/nixge.c b/drivers/net/ethernet/ni/nixge.c >>> index 19d043b593cc..b9091f9bbc77 100644 >>> --- a/drivers/net/ethernet/ni/nixge.c >>> +++ b/drivers/net/ethernet/ni/nixge.c >>> @@ -521,13 +521,15 @@ static netdev_tx_t nixge_start_xmit(struct sk_buff *skb, >>> if (nixge_check_tx_bd_space(priv, num_frag)) { >>> if (!netif_queue_stopped(ndev)) >>> netif_stop_queue(ndev); >>> - return NETDEV_TX_OK; >>> + return NETDEV_TX_BUSY; >>> } >> >> The driver should probably check the available room before returning >> from hard_start_xmit and turn the check above unlikely(). >> >> Btw there is no lock and the Tx completion is irq driven: the driver >> is racy. :o( >> > >Hi Francois, > >Thanks for you review. I'll make v2 according to your suggestion. >
you will probably need to check out: Transmit path guidelines: https://www.kernel.org/doc/Documentation/networking/driver.rst
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