CVE-2023-53338
lwt: Fix return values of BPF xmit ops
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
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.
Timeline
ID reserved
By Linux
- 1 day later
· 1 day later
Published
- 11 months later
· 11 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CISA-ADPADP (enrichment) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.55% · top 54% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Weakness
Affected products
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < 67f8f2bae8e7ac72e09def2b667e44704c4d1ee1
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < a97f221651fcdc891166e9bc270e3d9bfa5a0080
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < e3f647e4b642f9f6d32795a16f92c116c138d2af
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < 065d5f17096ec9161180e2c890afdff4dc6125f2
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < d68c17402442f5f494a2c3ebde5cb82f6aa9160a
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < 65583f9e070db7bece20710cfa2e3daeb0b831d9
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < 29b22badb7a84b783e3a4fffca16f7768fb31205
- affected 4.10
- unaffected < 4.10
- unaffected 5.4.257 – ≤ 5.4.*
- unaffected 5.10.195 – ≤ 5.10.*
- unaffected 5.15.132 – ≤ 5.15.*
- unaffected 6.1.53 – ≤ 6.1.*
- unaffected 6.4.16 – ≤ 6.4.*
- unaffected 6.5.3 – ≤ 6.5.*
- unaffected 6.6 – ≤ *
References (7)
- https://git.kernel.org/stable/c/67f8f2bae8e7ac72e09def2b667e44704c4d1ee1 (opens in a new tab)
- https://git.kernel.org/stable/c/a97f221651fcdc891166e9bc270e3d9bfa5a0080 (opens in a new tab)
- https://git.kernel.org/stable/c/e3f647e4b642f9f6d32795a16f92c116c138d2af (opens in a new tab)
- https://git.kernel.org/stable/c/065d5f17096ec9161180e2c890afdff4dc6125f2 (opens in a new tab)
- https://git.kernel.org/stable/c/d68c17402442f5f494a2c3ebde5cb82f6aa9160a (opens in a new tab)
- https://git.kernel.org/stable/c/65583f9e070db7bece20710cfa2e3daeb0b831d9 (opens in a new tab)
- https://git.kernel.org/stable/c/29b22badb7a84b783e3a4fffca16f7768fb31205 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://trackcve.app/cve/CVE-2023-53338)Record last updated .