| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 53/71] netlink: reset extack earlier in netlink_rcv_skb | Date | Mon, 29 Jan 2018 13:57:21 +0100 |
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4.14-stable review patch. If anyone has any objections, please let me know.
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From: Xin Long <lucien.xin@gmail.com>
[ Upstream commit cd443f1e91ca600a092e780e8250cd6a2954b763 ]
Move up the extack reset/initialization in netlink_rcv_skb, so that those 'goto ack' will not skip it. Otherwise, later on netlink_ack may use the uninitialized extack and cause kernel crash.
Fixes: cbbdf8433a5f ("netlink: extack needs to be reset each time through loop") Reported-by: syzbot+03bee3680a37466775e7@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/netlink/af_netlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2400,6 +2400,7 @@ int netlink_rcv_skb(struct sk_buff *skb, while (skb->len >= nlmsg_total_size(0)) { int msglen; + memset(&extack, 0, sizeof(extack)); nlh = nlmsg_hdr(skb); err = 0; @@ -2414,7 +2415,6 @@ int netlink_rcv_skb(struct sk_buff *skb, if (nlh->nlmsg_type < NLMSG_MIN_TYPE) goto ack; - memset(&extack, 0, sizeof(extack)); err = cb(skb, nlh, &extack); if (err == -EINTR) goto skip;
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