Re: [PATCH] bnx2x: Fix mem leak in bnx2x_tpa_stop() if build_skb() fails.

[Eric Dumazet <eric.dumazet@gmail.com>]

Le lundi 06 février 2012 à 22:28 +0100, Jesper Juhl a écrit :
> We allocate memory for 'new_data' with kmalloc(). If we get the memory
> we then try to build_skb() and if that should fail (which it can) we
> do not enter 'if (likely(skb)) {' and actually use 'new_data' but
> instead fall through to the 'drop:' label and end up returning from
> the function without ever assigning 'new'data' to anything or freeing
> it. That leaks the memory allocated to 'new_data'.
> 
> This patch fixes the memory leak by doing a kfree(new_data) in the
> case where build_skb() fails (or where allocation of 'new_data' itself
> fails, but in taht case it's just a harmless kfree(NULL)).
> 
> Signed-off-by: Jesper Juhl <jj@chaosbits.net>
> ---
>  drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c |    3 +--
>  1 files changed, 1 insertions(+), 2 deletions(-)
> 
>  No hardware to test, so compile tested only.
> 
> diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
> index 03f3935..7aee469 100644
> --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
> +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
> @@ -523,7 +523,6 @@ static void bnx2x_tpa_stop(struct bnx2x *bp, struct bnx2x_fastpath *fp,
>  		skb = build_skb(data);
>  
>  	if (likely(skb)) {
> -
>  #ifdef BNX2X_STOP_ON_ERROR
>  		if (pad + len > fp->rx_buf_size) {
>  			BNX2X_ERR("skb_put is about to fail...  "
> @@ -557,7 +556,7 @@ static void bnx2x_tpa_stop(struct bnx2x *bp, struct bnx2x_fastpath *fp,
>  
>  		return;
>  	}
> -
> +	kfree(new_data);
>  drop:
>  	/* drop the packet and keep the buffer in the bin */
>  	DP(NETIF_MSG_RX_STATUS,
> -- 
> 1.7.9
> 
> 

Good catch, my bad.

Thanks

Acked-by: Eric Dumazet <eric.dumazet@gmail.com>