Re: [PATCH 3.19 and earlier] fib_rules: Fix dump_rules() not to exit early

[Jiri Slaby <jslaby@suse.cz>]

On 10/05/2015, 07:29 PM, Roland Dreier wrote:
> From: Roland Dreier <roland@purestorage.com>
> 
> Backports of 41fc014332d9 ("fib_rules: fix fib rule dumps across
> multiple skbs") introduced a regression in "ip rule show" - it ends up
> dumping the first rule over and over and never exiting, because 3.19
> and earlier are missing commit 053c095a82cf ("netlink: make
> nlmsg_end() and genlmsg_end() void"), so fib_nl_fill_rule() ends up
> returning skb->len (i.e. > 0) in the success case.
> 
> Fix this by checking the return code for < 0 instead of != 0.
> 
> Signed-off-by: Roland Dreier <roland@purestorage.com>
> ---
> Hi, this is needed for all stable trees earlier than 4.0 that have
> picked up 41fc014332d9; so far looks like at least 3.10.y and 3.14.y
> have made such releases.
> 
>  net/core/fib_rules.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
> index 627e517077e4..84340a2605ed 100644
> --- a/net/core/fib_rules.c
> +++ b/net/core/fib_rules.c
> @@ -606,7 +606,7 @@ static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
>  		err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
>  				       cb->nlh->nlmsg_seq, RTM_NEWRULE,
>  				       NLM_F_MULTI, ops);
> -		if (err)
> +		if (err < 0)

I integrated the fix into the backport of 41fc014332d9 in 3.12 and made
a note in there. Thanks!

-- 
js
suse labs