lwt: Fix return values of BPF xmit ops
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 5 fixed, 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: lwt: Fix return values of BPF xmit ops BPF encap ops can return different types of positive values, such like NET_RX_DROP, NET_XMIT_CN, NETDEV_TX_BUSY, and so on, from function skb_do_redirect and bpf_lwt_xmit_reroute. At the xmit hook, such return values would be treated implicitly as LWTUNNEL_XMIT_CONTINUE in ip(6)_finish_output2. When this happens, skbs that have been freed would continue to the neighbor subsystem, causing use-after-free bug and kernel crashes. To fix the incorrect behavior, skb_do_redirect return values can be simply discarded, the same as tc-egress behavior. On the other hand, bpf_lwt_xmit_reroute returns useful errors to local senders, e.g. PMTU information. Thus convert its return values to avoid the conflict with LWTUNNEL_XMIT_CONTINUE.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
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 | 4.10 and later | 5.4.257, 5.10.195, 5.15.132, 6.1.53, 6.4.16, 6.5.3, 6.6 | Patch available | CNA |
- Linux VendorLinux Affected 4.10 and later Fixed in 5.4.257, 5.10.195, 5.15.132, 6.1.53, 6.4.16, 6.5.3, 6.6 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.10 to before 5.4.257; 5.5 to before 5.10.195; 5.11 to before 5.15.132; 5.16 to before 6.1.53; 6.2 to before 6.4.16; 6.5 to before 6.5.3 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.10 to before 5.4.257; 5.5 to before 5.10.195; 5.11 to before 5.15.132; 5.16 to before 6.1.53; 6.2 to before 6.4.16; 6.5 to before 6.5.3 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.4.257, 5.10.195, 5.15.132, 6.1.53, 6.4.16, 6.5.3, 6.6
Red Hat 1 advisory
- RHSA-2024:2394 Released 2024-04-30 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-427.13.1.el9_4, kernel-64k-debug-devel-matched-5.14.0-427.13.1.el9_4, kernel-64k-devel-5.14.0-427.13.1.el9_4 +11
- Red Hat Enterprise Linux BaseOS (v. 9) bpftool-7.3.0-427.13.1.el9_4, kernel-5.14.0-427.13.1.el9_4, kernel-64k-5.14.0-427.13.1.el9_4 +29
- Red Hat Enterprise Linux CRB (v. 9) kernel-tools-libs-devel-5.14.0-427.13.1.el9_4, libperf-5.14.0-427.13.1.el9_4
- Red Hat Enterprise Linux NFV (v. 9) kernel-rt-5.14.0-427.13.1.el9_4, kernel-rt-core-5.14.0-427.13.1.el9_4, kernel-rt-debug-5.14.0-427.13.1.el9_4 +11
- Red Hat Enterprise Linux RT (v. 9) kernel-rt-5.14.0-427.13.1.el9_4, kernel-rt-core-5.14.0-427.13.1.el9_4, kernel-rt-debug-5.14.0-427.13.1.el9_4 +9
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2024:2394 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2024:2394 |
| Red Hat Enterprise Linux CRB (v. 9) | Fixed | RHSA-2024:2394 |
| Red Hat Enterprise Linux NFV (v. 9) | Fixed | RHSA-2024:2394 |
| Red Hat Enterprise Linux RT (v. 9) | Fixed | RHSA-2024:2394 |
Not affected: 3 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2023-53338
- 2026-10-03 Alias added: GHSA-wqfp-wxf7-9vr7
References
Patch 7
- https://git.kernel.org/stable/c/67f8f2bae8e7ac72e09def2b667e44704c4d1ee1
- https://git.kernel.org/stable/c/a97f221651fcdc891166e9bc270e3d9bfa5a0080
- https://git.kernel.org/stable/c/e3f647e4b642f9f6d32795a16f92c116c138d2af
- https://git.kernel.org/stable/c/065d5f17096ec9161180e2c890afdff4dc6125f2
- https://git.kernel.org/stable/c/d68c17402442f5f494a2c3ebde5cb82f6aa9160a
- https://git.kernel.org/stable/c/65583f9e070db7bece20710cfa2e3daeb0b831d9
- https://git.kernel.org/stable/c/29b22badb7a84b783e3a4fffca16f7768fb31205
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-2023-53338 · CVE Program
- CVE-2023-53338 · NVD
- FIRST EPSS
- GHSA-wqfp-wxf7-9vr7 · GitHub Advisory Database · CC BY 4.0
- CVE-2023-53338 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences