On Fri, Jun 01, 2018 at 08:50:16AM -0700, dsah...@kernel.org wrote:
> From: David Ahern <dsah...@gmail.com>
>
> A recent commit changed rtnl_talk_* to return the response message in
> allocated memory so callers need to free it. The change to name_is_vrf
> did not save the device index which is pointing to a struct inside the
> now allocated and freed memory resulting in garbage getting returned
> in some cases.
>
> Fix by using a stack variable to save the return value and only set
> it to ifi->ifi_index after all checks are done and before the answer
> buffer is freed.
>
> Fixes: 86bf43c7c2fdc ("lib/libnetlink: update rtnl_talk to support malloc
> buff at run time")
> Cc: Hangbin Liu <liuhang...@gmail.com>
> Cc: Phil Sutter <p...@nwl.cc>
> Signed-off-by: David Ahern <dsah...@gmail.com>
> ---
> ip/iplink_vrf.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/ip/iplink_vrf.c b/ip/iplink_vrf.c
> index e9dd0df98412..6004bb4f305e 100644
> --- a/ip/iplink_vrf.c
> +++ b/ip/iplink_vrf.c
> @@ -191,6 +191,7 @@ int name_is_vrf(const char *name)
> struct rtattr *tb[IFLA_MAX+1];
> struct rtattr *li[IFLA_INFO_MAX+1];
> struct ifinfomsg *ifi;
> + int ifindex = 0;
> int len;
>
> addattr_l(&req.n, sizeof(req), IFLA_IFNAME, name, strlen(name) + 1);
> @@ -218,7 +219,8 @@ int name_is_vrf(const char *name)
> if (strcmp(RTA_DATA(li[IFLA_INFO_KIND]), "vrf"))
> goto out;
>
> + ifindex = ifi->ifi_index;
> out:
> free(answer);
> - return ifi->ifi_index;
> + return ifindex;
> }
> --
> 2.11.0
>
Thanks for the fix.
Acked-by: Hangbin Liu <liuhang...@gmail.com>
