From: Sameeh Jubran Date: Wed, 1 May 2019 16:47:04 +0300 Subject: [PATCH] net: ena: fix: set freed objects to NULL to avoid failing future allocations Origin: https://git.kernel.org/linus/8ee8ee7fe87bf64738ab4e31be036a7165608b27 Bug-Debian: https://bugs.debian.org/941291 In some cases when a queue related allocation fails, successful past allocations are freed but the pointer that pointed to them is not set to NULL. This is a problem for 2 reasons: 1. This is generally a bad practice since this pointer might be accidentally accessed in the future. 2. Future allocations using the same pointer check if the pointer is NULL and fail if it is not. Fixed this by setting such pointers to NULL in the allocation of queue related objects. Also refactored the code of ena_setup_tx_resources() to goto-style error handling to avoid code duplication of resource freeing. Fixes: 1738cd3ed342 ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)") Signed-off-by: Arthur Kiyanovski Signed-off-by: Sameeh Jubran Signed-off-by: David S. Miller --- drivers/net/ethernet/amazon/ena/ena_netdev.c | 25 ++++++++++++-------- 1 file changed, 15 insertions(+), 10 deletions(-) Index: linux/drivers/net/ethernet/amazon/ena/ena_netdev.c =================================================================== --- linux.orig/drivers/net/ethernet/amazon/ena/ena_netdev.c +++ linux/drivers/net/ethernet/amazon/ena/ena_netdev.c @@ -224,28 +224,23 @@ static int ena_setup_tx_resources(struct if (!tx_ring->tx_buffer_info) { tx_ring->tx_buffer_info = vzalloc(size); if (!tx_ring->tx_buffer_info) - return -ENOMEM; + goto err_tx_buffer_info; } size = sizeof(u16) * tx_ring->ring_size; tx_ring->free_tx_ids = vzalloc_node(size, node); if (!tx_ring->free_tx_ids) { tx_ring->free_tx_ids = vzalloc(size); - if (!tx_ring->free_tx_ids) { - vfree(tx_ring->tx_buffer_info); - return -ENOMEM; - } + if (!tx_ring->free_tx_ids) + goto err_free_tx_ids; } size = tx_ring->tx_max_header_size; tx_ring->push_buf_intermediate_buf = vzalloc_node(size, node); if (!tx_ring->push_buf_intermediate_buf) { tx_ring->push_buf_intermediate_buf = vzalloc(size); - if (!tx_ring->push_buf_intermediate_buf) { - vfree(tx_ring->tx_buffer_info); - vfree(tx_ring->free_tx_ids); - return -ENOMEM; - } + if (!tx_ring->push_buf_intermediate_buf) + goto err_push_buf_intermediate_buf; } /* Req id ring for TX out of order completions */ @@ -259,6 +254,15 @@ static int ena_setup_tx_resources(struct tx_ring->next_to_clean = 0; tx_ring->cpu = ena_irq->cpu; return 0; + +err_push_buf_intermediate_buf: + vfree(tx_ring->free_tx_ids); + tx_ring->free_tx_ids = NULL; +err_free_tx_ids: + vfree(tx_ring->tx_buffer_info); + tx_ring->tx_buffer_info = NULL; +err_tx_buffer_info: + return -ENOMEM; } /* ena_free_tx_resources - Free I/O Tx Resources per Queue @@ -378,6 +382,7 @@ static int ena_setup_rx_resources(struct rx_ring->free_rx_ids = vzalloc(size); if (!rx_ring->free_rx_ids) { vfree(rx_ring->rx_buffer_info); + rx_ring->rx_buffer_info = NULL; return -ENOMEM; } }