In the Linux kernel, the following vulnerability has been resolved:
xfrm6: clear dst.dev on error to avoid double netdev_put in xfrm6_fill_dst()
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 ...
CVSS Details
- CVSS 3.1 Base Score: 7.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon_linux_2023 | — | Upgrade perf6.12-debuginfoUpgrade python3-perf6.12Upgrade kernel6.12Upgrade bpftool6.12-debuginfoUpgrade kernel6.12-develUpgrade kernel6.12-modules-extraUpgrade kernel6.12-tools-debuginfoUpgrade kernel6.12-debuginfo-common-x86_64Upgrade kernel6.12-tools-develUpgrade kernel6.12-headersUpgrade python3-perf6.12-debuginfoUpgrade kernel6.12-debuginfo-common-aarch64Upgrade bpftool6.12Upgrade kernel6.12-debuginfoUpgrade kernel6.12-toolsUpgrade kernel6.12-modules-extra-commonUpgrade perf6.12Upgrade kernel-livepatch-6.12.103-127.188 | Sep 1, 2026 | Aug 5, 2026 |
| Debian | — | Upgrade linux-6.12Upgrade linux | Aug 9, 2026 | Aug 9, 2026 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Aug 14, 2026 | Aug 5, 2026 |
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