Re: [dpdk-dev] [PATCH] net/ixgbe: fix using heap pointer after free

["Wang, Haiyue" <haiyue.wang@intel.com>]

> -----Original Message-----
> From: Yu, DapengX <dapengx.yu@intel.com>
> Sent: Friday, July 9, 2021 10:30
> To: Wang, Haiyue <haiyue.wang@intel.com>
> Cc: dev@dpdk.org; Yu, DapengX <dapengx.yu@intel.com>; stable@dpdk.org
> Subject: [PATCH] net/ixgbe: fix using heap pointer after free
> 
> From: Dapeng Yu <dapengx.yu@intel.com>
> 
> The original code use a heap pointer after it is freed.
> This patch fix it.
> 
> Fixes: a14de8b498d1 ("net/ixgbe: destroy consistent filter")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Dapeng Yu <dapengx.yu@intel.com>
> ---
>  drivers/net/ixgbe/ixgbe_flow.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ixgbe/ixgbe_flow.c b/drivers/net/ixgbe/ixgbe_flow.c
> index 0b10e91a9b..4db5ef4b2b 100644
> --- a/drivers/net/ixgbe/ixgbe_flow.c
> +++ b/drivers/net/ixgbe/ixgbe_flow.c
> @@ -32,6 +32,7 @@
>  #include <rte_hash_crc.h>
>  #include <rte_flow.h>
>  #include <rte_flow_driver.h>
> +#include <rte_tailq.h>
> 
>  #include "ixgbe_logs.h"
>  #include "base/ixgbe_api.h"
> @@ -3339,6 +3340,7 @@ ixgbe_flow_destroy(struct rte_eth_dev *dev,
>  	struct ixgbe_hw_fdir_info *fdir_info =
>  		IXGBE_DEV_PRIVATE_TO_FDIR_INFO(dev->data->dev_private);
>  	struct ixgbe_rss_conf_ele *rss_filter_ptr;
> +	void *tmp;
> 
>  	switch (filter_type) {
>  	case RTE_ETH_FILTER_NTUPLE:
> @@ -3432,7 +3434,7 @@ ixgbe_flow_destroy(struct rte_eth_dev *dev,
>  		return ret;
>  	}
> 
> -	TAILQ_FOREACH(ixgbe_flow_mem_ptr, &ixgbe_flow_list, entries) {
> +	TAILQ_FOREACH_SAFE(ixgbe_flow_mem_ptr, &ixgbe_flow_list, entries, tmp) {
>  		if (ixgbe_flow_mem_ptr->flow == pmd_flow) {
>  			TAILQ_REMOVE(&ixgbe_flow_list,
>  				ixgbe_flow_mem_ptr, entries);

This is "find - free" process, and only one 'pmd_flow' in the list,
so just "break;" is fine.

	TAILQ_FOREACH(ixgbe_flow_mem_ptr, &ixgbe_flow_list, entries) {
		if (ixgbe_flow_mem_ptr->flow == pmd_flow) {
			TAILQ_REMOVE(&ixgbe_flow_list,
				ixgbe_flow_mem_ptr, entries);
			rte_free(ixgbe_flow_mem_ptr);
			break; <------
		}
	}

> --
> 2.27.0