netdev - Re: [PATCH v1 1/1 net-next] 8139cp: Fix one possible deadloop in cp_rx

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 25 Aug 2016 22:37:20 +0800
From:   Feng Gao <gfree.wind@...il.com>
To:     Gao Feng <fgao@...ai8.com>
Cc:     dwmw2@...radead.org, "David S. Miller" <davem@...emloft.net>,
        Linux Kernel Network Developers <netdev@...r.kernel.org>
Subject: Re: [PATCH v1 1/1 net-next] 8139cp: Fix one possible deadloop in cp_rx_poll

On Thu, Aug 25, 2016 at 9:45 AM,  <fgao@...ai8.com> wrote:
> From: Gao Feng <fgao@...ai8.com>
>
> When cp_rx_poll does not get enough packet, it will check the rx
> interrupt status again. If so, it will jumpt to rx_status_loop again.
> But the goto jump resets the rx variable as zero too.
>
> As a result, it causes one possible deadloop. Assume this case,
> rx_status_loop only gets the packet count which is less than budget,
> and (cpr16(IntrStatus) & cp_rx_intr_mask) condition is always true.
> It causes the deadloop happens and system is blocked.
>
> Signed-off-by: Gao Feng <fgao@...ai8.com>
> ---
>  drivers/net/ethernet/realtek/8139cp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/realtek/8139cp.c b/drivers/net/ethernet/realtek/8139cp.c
> index deae10d..5297bf7 100644
> --- a/drivers/net/ethernet/realtek/8139cp.c
> +++ b/drivers/net/ethernet/realtek/8139cp.c
> @@ -467,8 +467,8 @@ static int cp_rx_poll(struct napi_struct *napi, int budget)
>         unsigned int rx_tail = cp->rx_tail;
>         int rx;
>
> -rx_status_loop:
>         rx = 0;
> +rx_status_loop:
>         cpw16(IntrStatus, cp_rx_intr_mask);
>
>         while (rx < budget) {
> --
> 1.9.1
>
>

Sorry, this commit should be for net.git, not net-next.git
Because it fixed one possible infinite loop.

Best Regards
Feng