CVE-2023-53338 (GCVE-0-2023-53338)

Vulnerability from cvelistv5 – Published: 2025-09-17 14:56 – Updated: 2026-01-14 18:43
VLAI?
Title
lwt: Fix return values of BPF xmit ops
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.
Severity ?
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 , < 67f8f2bae8e7ac72e09def2b667e44704c4d1ee1 (git)
Affected: 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 , < a97f221651fcdc891166e9bc270e3d9bfa5a0080 (git)
Affected: 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 , < e3f647e4b642f9f6d32795a16f92c116c138d2af (git)
Affected: 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 , < 065d5f17096ec9161180e2c890afdff4dc6125f2 (git)
Affected: 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 , < d68c17402442f5f494a2c3ebde5cb82f6aa9160a (git)
Affected: 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 , < 65583f9e070db7bece20710cfa2e3daeb0b831d9 (git)
Affected: 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 , < 29b22badb7a84b783e3a4fffca16f7768fb31205 (git)
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    Linux Linux Affected: 4.10
Unaffected: 0 , < 4.10 (semver)
Unaffected: 5.4.257 , ≤ 5.4.* (semver)
Unaffected: 5.10.195 , ≤ 5.10.* (semver)
Unaffected: 5.15.132 , ≤ 5.15.* (semver)
Unaffected: 6.1.53 , ≤ 6.1.* (semver)
Unaffected: 6.4.16 , ≤ 6.4.* (semver)
Unaffected: 6.5.3 , ≤ 6.5.* (semver)
Unaffected: 6.6 , ≤ * (original_commit_for_fix)
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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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