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| author | Dong Chenchen <dongchenchen2@huawei.com> | 2026-06-09 17:21:17 +0800 |
|---|---|---|
| committer | Steffen Klassert <steffen.klassert@secunet.com> | 2026-06-12 08:39:59 +0200 |
| commit | 8045c0df98d4f14c54e5cb875f1c9c0ce89fe4ff (patch) | |
| tree | 777479e93eb68965a85a5140e289573b629de389 /net/ipv4 | |
| parent | d129c3177d7b1138fd5066fcc63a698b3ba415b0 (diff) | |
| download | linux-next-8045c0df98d4f14c54e5cb875f1c9c0ce89fe4ff.tar.gz linux-next-8045c0df98d4f14c54e5cb875f1c9c0ce89fe4ff.zip | |
xfrm: Fix dev use-after-free in xfrm async resumption
xfrm async resumption hold skb->dev refcnt until after transport_finish.
However, xfrm_rcv_cb may modify skb->dev to tunnel dev without taking
device reference, such as vti_rcv_cb. The subsequent async resumption
will decrement the tunnel device's reference count, which lead to uaf
of tunnel dev and refcnt leak of orig dev as below:
unregister_netdevice: waiting for vti1 to become free. Usage count = -2
Stash the original skb->dev to fix refcnt imbalance. The new skb->dev set
by xfrm_rcv_cb can race with device teardown. Extend rcu protection over
xfrm_rcv_cb and transport_finish to prevent races.
Fixes: 1c428b038400 ("xfrm: hold dev ref until after transport_finish NF_HOOK")
Reported-by: Xu Chunxiao <xuchunxiao3@huawei.com>
Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/xfrm4_input.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c index c2eac844bcdb..f6f2a8ef3f88 100644 --- a/net/ipv4/xfrm4_input.c +++ b/net/ipv4/xfrm4_input.c @@ -76,8 +76,6 @@ int xfrm4_transport_finish(struct sk_buff *skb, int async) NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, dev_net(dev), NULL, skb, dev, NULL, xfrm4_rcv_encap_finish); - if (async) - dev_put(dev); return 0; } |