RE: [patch 37/37] sit: fix off-by-one in ipip6_tunnel_get_prl

Templin, Fred L
2009-10-10T01:14:35Z

Wait a moment - I remember now that this code came
from Yoshifuji, and I believe there was a reason for
the cmax+1. The application is expected to know this
and to post a large enough buffer.

Can we put this on hold until I have had a chance to
check my e-mail archives and my local iproute changes
(will respond on monday)?

Thanks - Fred
fred.l.templin@boeing.com

> -----Original Message-----
> From: Greg KH [mailto:gregkh@suse.de]
> Sent: Friday, October 09, 2009 4:35 PM
> To: linux-kernel@vger.kernel.org; stable@kernel.org
> Cc: stable-review@kernel.org; torvalds@linux-foundation.org; akpm@linux-foundation.org;
> alan@lxorguk.ukuu.org.uk; Sascha Hlusiak; Templin, Fred L; David S. Miller
> Subject: [patch 37/37] sit: fix off-by-one in ipip6_tunnel_get_prl
>
> 2.6.31-stable review patch. If anyone has any objections, please let us know.
>
> ------------------
> From: Sascha Hlusiak <contact@saschahlusiak.de>
>
> [ Upstream commit 298bf12ddb25841804f26234a43b89da1b1c0e21 ]
>
> When requesting all prl entries (kprl.addr == INADDR_ANY) and there are
> more prl entries than there is space passed from userspace, the existing
> code would always copy cmax+1 entries, which is more than can be handled.
>
> This patch makes the kernel copy only exactly cmax entries.
>
> Signed-off-by: Sascha Hlusiak <contact@saschahlusiak.de>
> Acked-By: Fred L. Templin <Fred.L.Templin@boeing.com>
> Signed-off-by: David S. Miller <davem@davemloft.net>
> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
> ---
> net/ipv6/sit.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/net/ipv6/sit.c
> +++ b/net/ipv6/sit.c
> @@ -313,7 +313,7 @@ static int ipip6_tunnel_get_prl(struct i
>
> c = 0;
> for (prl = t->prl; prl; prl = prl->next) {
> - if (c > cmax)
> + if (c >= cmax)
> break;
> if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
> continue;
>