diff mbox series

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

Message ID 20201112094237.4288-1-xie.he.0141@gmail.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series [net] net: x25: Increase refcnt of "struct x25_neigh" in x25_rx_call_request | expand

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netdev/cover_letter success Link
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netdev/subject_prefix success Link
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 7 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Xie He Nov. 12, 2020, 9:42 a.m. UTC
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, in 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: 4becb7ee5b3d ("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>
---
 net/x25/af_x25.c | 1 +
 1 file changed, 1 insertion(+)
diff mbox series

Patch

diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
index 046d3fee66a9..a10487e7574c 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -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;