Re: net: GPF in __netlink_ns_capable

On Sat, Jan 16, 2016 at 01:08:33AM +0100, Richard Weinberger wrote:

On Fri, Jan 15, 2016 at 11:31 PM, Dmitry Vyukov [off-list ref] wrote:

quoted

Call Trace:
 [<     inline     >] netlink_ns_capable net/netlink/af_netlink.c:1417
 [<ffffffff8529c0a5>] netlink_capable+0x25/0x30 net/netlink/af_netlink.c:1432

Hmm, we're crashing because NETLINK_CB(skb).sk is NULL.
netlink_dump() creates a new skb without a netlink control block,
but infiniband's dump functions use netlink_capable() which needs a valid
NETLINK_CB(skb).sk.

What about something like that?

No you can't do it here as netlink_unicast also calls this and for
that case you'd be overwriting the original sending user-space
socket with the kernel socket.

I'm adding Eric Bierderman as he wrote some of the code in question.

Cheers,
-- 
Email: Herbert Xu [off-list ref]
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