Commit 4ee18c17 authored Nov 12, 2020 by Xie He Committed by Jakub Kicinski Nov 12, 2020

net: x25: Increase refcnt of "struct x25_neigh" in x25_rx_call_request



The x25_disconnect function in x25_subr.c would decrease the refcount of
"x25->neighbour" (struct x25_neigh) and reset this pointer to NULL.

However, the x25_rx_call_request function in af_x25.c, which is called
when we receive a connection request, does not increase the refcount when
it assigns the pointer.

Fix this issue by increasing the refcount of "struct x25_neigh" in
x25_rx_call_request.

This patch fixes frequent kernel crashes when using AF_X25 sockets.

Fixes: 4becb7ee ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect")
Cc: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Link: https://lore.kernel.org/r/20201112103506.5875-1-xie.he.0141@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent baee1991

net/x25/af_x25.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -1050,6 +1050,7 @@ int x25_rx_call_request(struct sk_buff skb, struct x25_neigh nb,
		makex25->lci = lci;
		makex25->dest_addr = dest_addr;
		makex25->source_addr = source_addr;
		x25_neigh_hold(nb);
		makex25->neighbour = nb;
		makex25->facilities = facilities;
		makex25->dte_facilities= dte_facilities;

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