[ovs-dev] [PATCH] netdev-linux: Avoid division by 0 if kernel reports bad scheduler data.

[Yifeng Sun]

Looks good to me, thanks.

Reviewed-by: Yifeng Sun <pkusunyifeng at gmail.com>

On Sat, Aug 18, 2018 at 10:17 AM, Ben Pfaff <blp at ovn.org> wrote:

> If the kernel reported a value of 0 for the second value in
> /proc/net/psched, it would cause a division-by-zero fault in
> read_psched().  I don't know of a kernel that would actually do that, but
> it's still better to be safe.
>
> Found by clang static analyzer
>
> Reported-by: Bhargava Shastry <bshastry at sect.tu-berlin.de>
> Signed-off-by: Ben Pfaff <blp at ovn.org>
> ---
>  lib/netdev-linux.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c
> index 0c42268d9d6c..e16ea58a085e 100644
> --- a/lib/netdev-linux.c
> +++ b/lib/netdev-linux.c
> @@ -5166,7 +5166,7 @@ read_psched(void)
>      VLOG_DBG("%s: psched parameters are: %u %u %u %u", fn, a, b, c, d);
>      fclose(stream);
>
> -    if (!a || !c) {
> +    if (!a || !b || !c) {
>          VLOG_WARN("%s: invalid scheduler parameters", fn);
>          goto exit;
>      }
> --
> 2.16.1
>
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