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| author | Xiang Mei (Microsoft) <xmei5@asu.edu> | 2026-07-02 04:05:16 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-08-03 12:17:02 +0300 |
| commit | 43de8a49335e611adb271bbd52e84dfbc11fc185 (patch) | |
| tree | 87c3d92703d5369c5fd69984a6b4bccbbca2ea82 | |
| parent | a6ecc36b16e7e6f06f7b757060de8ac124433d84 (diff) | |
| download | linux-43de8a49335e611adb271bbd52e84dfbc11fc185.tar.xz | |
xfrm6: clear dst.dev on error to avoid double netdev_put in xfrm6_fill_dst()
[ Upstream commit 136992de9bb91871084ae52d172610541c76e4d2 ]
On the error path where in6_dev_get(dev) returns NULL, xfrm6_fill_dst()
releases the device reference with netdev_put() but leaves
xdst->u.dst.dev set. dst_destroy() later calls netdev_put(dst->dev)
again, so the same net_device reference is released twice, underflowing
its refcount (ref_tracker WARNING + "unregister_netdevice: waiting for
<dev> to become free").
Clear xdst->u.dst.dev after the netdev_put(), the same way the XFRM
device-offload paths xfrm_dev_state_add() and xfrm_dev_policy_add() in
net/xfrm/xfrm_device.c NULL ->dev when releasing the reference on error.
ref_tracker: reference already released.
ref_tracker: allocated in:
xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:86)
...
udpv6_sendmsg (net/ipv6/udp.c:1696)
...
ref_tracker: freed in:
xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:90)
...
WARNING: lib/ref_tracker.c:322 at ref_tracker_free+0x58b/0x780
dst_destroy (net/core/dst.c:115)
rcu_core
handle_softirqs
...
Fixes: 84c4a9dfbf43 ("xfrm6: release dev before returning error")
Reported-by: AutonomousCodeSecurity@microsoft.com
Signed-off-by: Xiang Mei (Microsoft) <xmei5@asu.edu>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/ipv6/xfrm6_policy.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c index 125ea9a5b8a0..3b749475f6ed 100644 --- a/net/ipv6/xfrm6_policy.c +++ b/net/ipv6/xfrm6_policy.c @@ -88,6 +88,7 @@ static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, xdst->u.rt6.rt6i_idev = in6_dev_get(dev); if (!xdst->u.rt6.rt6i_idev) { netdev_put(dev, &xdst->u.dst.dev_tracker); + xdst->u.dst.dev = NULL; return -ENODEV; } |