[PATCH 3.14 70/84] fib_rules: fix fib rule dumps across multiple skbs

From: Greg Kroah-Hartman
Date: Tue Sep 29 2015 - 11:23:35 EST

3.14-stable review patch. If anyone has any objections, please let me know.


From: Wilson Kok <wkok@xxxxxxxxxxxxxxxxxxx>

[ Upstream commit 41fc014332d91ee90c32840bf161f9685b7fbf2b ]

dump_rules returns skb length and not error.
But when family == AF_UNSPEC, the caller of dump_rules
assumes that it returns an error. Hence, when family == AF_UNSPEC,
we continue trying to dump on -EMSGSIZE errors resulting in
incorrect dump idx carried between skbs belonging to the same dump.
This results in fib rule dump always only dumping rules that fit
into the first skb.

This patch fixes dump_rules to return error so that we exit correctly
and idx is correctly maintained between skbs that are part of the
same dump.

Signed-off-by: Wilson Kok <wkok@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Roopa Prabhu <roopa@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
net/core/fib_rules.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -621,15 +621,17 @@ static int dump_rules(struct sk_buff *sk
int idx = 0;
struct fib_rule *rule;
+ int err = 0;

list_for_each_entry_rcu(rule, &ops->rules_list, list) {
if (idx < cb->args[1])
goto skip;

- if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
- cb->nlh->nlmsg_seq, RTM_NEWRULE,
- NLM_F_MULTI, ops) < 0)
+ err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq, RTM_NEWRULE,
+ NLM_F_MULTI, ops);
+ if (err)
@@ -638,7 +640,7 @@ skip:
cb->args[1] = idx;

- return skb->len;
+ return err;

static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
@@ -654,7 +656,9 @@ static int fib_nl_dumprule(struct sk_buf
if (ops == NULL)

- return dump_rules(skb, cb, ops);
+ dump_rules(skb, cb, ops);
+ return skb->len;


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/