From d883a0367149506e8b7a3f31891d1ea30b9377f3 Mon Sep 17 00:00:00 2001 From: "Denis V. Lunev" Date: Fri, 21 Dec 2007 02:01:53 -0800 Subject: [IPV4]: OOPS with NETLINK_FIB_LOOKUP netlink socket [ Regression added by changeset: cd40b7d3983c708aabe3d3008ec64ffce56d33b0 [NET]: make netlink user -> kernel interface synchronious -DaveM ] nl_fib_input re-reuses incoming skb to send the reply. This means that this packet will be freed twice, namely in: - netlink_unicast_kernel - on receive path Use clone to send as a cure, the caller is responsible for kfree_skb on error. Thanks to Alexey Dobryan, who originally found the problem. Signed-off-by: Denis V. Lunev Signed-off-by: David S. Miller --- net/ipv4/fib_frontend.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 732d8f088b13..97abf934d185 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -804,10 +804,13 @@ static void nl_fib_input(struct sk_buff *skb) nlh = nlmsg_hdr(skb); if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len || - nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn))) { - kfree_skb(skb); + nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn))) return; - } + + skb = skb_clone(skb, GFP_KERNEL); + if (skb == NULL) + return; + nlh = nlmsg_hdr(skb); frn = (struct fib_result_nl *) NLMSG_DATA(nlh); tb = fib_get_table(frn->tb_id_in); -- cgit v1.2.3