From 2e9fa3513ddee1bcb6e50179a9b9f542f17bba33 Mon Sep 17 00:00:00 2001
From: Xiaodong Xu <stid.smth@gmail.com>
Date: Mon, 11 Nov 2019 15:05:46 -0800
Subject: [PATCH] xfrm: release device reference for invalid state
Git-commit: 4944a4b1077f74d89073624bd286219d2fcbfce3
Patch-mainline: v5.4-rc8
References: git-fixes
An ESP packet could be decrypted in async mode if the input handler for
this packet returns -EINPROGRESS in xfrm_input(). At this moment the device
reference in skb is held. Later xfrm_input() will be invoked again to
resume the processing.
If the transform state is still valid it would continue to release the
device reference and there won't be a problem; however if the transform
state is not valid when async resumption happens, the packet will be
dropped while the device reference is still being held.
When the device is deleted for some reason and the reference to this
device is not properly released, the kernel will keep logging like:
unregister_netdevice: waiting for ppp2 to become free. Usage count = 1
The issue is observed when running IPsec traffic over a PPPoE device based
on a bridge interface. By terminating the PPPoE connection on the server
end for multiple times, the PPPoE device on the client side will eventually
get stuck on the above warning message.
This patch will check the async mode first and continue to release device
reference in async resumption, before it is dropped due to invalid state.
v2: Do not assign address family from outer_mode in the transform if the
state is invalid
v3: Release device reference in the error path instead of jumping to resume
Fixes: 4ce3dbe397d7b ("xfrm: Fix xfrm_input() to verify state is valid when (encap_type < 0)")
Signed-off-by: Xiaodong Xu <stid.smth@gmail.com>
Reported-by: Bo Chen <chenborfc@163.com>
Tested-by: Bo Chen <chenborfc@163.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
net/xfrm/xfrm_input.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index b536ffabe712..97ad725e52c2 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -244,6 +244,9 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
else
XFRM_INC_STATS(net,
LINUX_MIB_XFRMINSTATEINVALID);
+
+ if (encap_type == -1)
+ dev_put(skb->dev);
goto drop;
}
--
2.16.4