net: fix a memleak when uncloning an skb dst and its metadata
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 4 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-401.
Summary
In the Linux kernel, the following vulnerability has been resolved: net: fix a memleak when uncloning an skb dst and its metadata When uncloning an skb dst and its associated metadata, a new dst+metadata is allocated and later replaces the old one in the skb. This is helpful to have a non-shared dst+metadata attached to a specific skb. The issue is the uncloned dst+metadata is initialized with a refcount of 1, which is increased to 2 before attaching it to the skb. When tun_dst_unclone returns, the dst+metadata is only referenced from a single place (the skb) while its refcount is 2. Its refcount will never drop to 0 (when the skb is consumed), leading to a memory leak. Fix this by removing the call to dst_hold in tun_dst_unclone, as the dst+metadata refcount is already 1.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 4.3 and later | 4.9.302, 4.14.267, 4.19.230, 5.4.180, 5.10.101, 5.15.24, 5.16.10, 5.17 | Patch available | CNA |
- Linux VendorLinux Affected 4.3 and later Fixed in 4.9.302, 4.14.267, 4.19.230, 5.4.180, 5.10.101, 5.15.24, 5.16.10, 5.17 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.3 to before 4.9.302; 4.10 to before 4.14.267; 4.15 to before 4.19.230; 4.20 to before 5.4.180; 5.5 to before 5.10.101; 5.11 to before 5.15.24; 5.16 to before 5.16.10 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.3 to before 4.9.302; 4.10 to before 4.14.267; 4.15 to before 4.19.230; 4.20 to before 5.4.180; 5.5 to before 5.10.101; 5.11 to before 5.15.24; 5.16 to before 5.16.10 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.9.302, 4.14.267, 4.19.230, 5.4.180, 5.10.101, 5.15.24, 5.16.10, 5.17
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-02 Threatist record created from CVE-2022-48809
- 2026-10-03 Alias added: GHSA-7jv7-gr8j-4554
References
Patch 8
- https://git.kernel.org/stable/c/4ac84498fbe84a00e7aef185e2bb3e40ce71eca4
- https://git.kernel.org/stable/c/c1ff27d100e2670b03cbfddb9117e5f9fc672540
- https://git.kernel.org/stable/c/0be943916d781df2b652793bb2d3ae4f9624c10a
- https://git.kernel.org/stable/c/a80817adc2a4c1ba26a7aa5f3ed886e4a18dff88
- https://git.kernel.org/stable/c/00e6d6c3bc14dfe32824e2c515f0e0f2d6ecf2f1
- https://git.kernel.org/stable/c/fdcb263fa5cda15b8cb24a641fa2718c47605314
- https://git.kernel.org/stable/c/8b1087b998e273f07be13dcb5f3ca4c309c7f108
- https://git.kernel.org/stable/c/9eeabdf17fa0ab75381045c867c370f4cc75a613
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2022-48809 · CVE Program
- CVE-2022-48809 · NVD
- FIRST EPSS
- GHSA-7jv7-gr8j-4554 · GitHub Advisory Database · CC BY 4.0
- CVE-2022-48809 · Red Hat security data · CC BY 4.0
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