{"id":"CVE-2023-53338","summary":"lwt: Fix return values of BPF xmit ops","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nlwt: Fix return values of BPF xmit ops\n\nBPF encap ops can return different types of positive values, such like\nNET_RX_DROP, NET_XMIT_CN, NETDEV_TX_BUSY, and so on, from function\nskb_do_redirect and bpf_lwt_xmit_reroute. At the xmit hook, such return\nvalues would be treated implicitly as LWTUNNEL_XMIT_CONTINUE in\nip(6)_finish_output2. When this happens, skbs that have been freed would\ncontinue to the neighbor subsystem, causing use-after-free bug and\nkernel crashes.\n\nTo fix the incorrect behavior, skb_do_redirect return values can be\nsimply discarded, the same as tc-egress behavior. On the other hand,\nbpf_lwt_xmit_reroute returns useful errors to local senders, e.g. PMTU\ninformation. Thus convert its return values to avoid the conflict with\nLWTUNNEL_XMIT_CONTINUE.","modified":"2026-04-02T09:44:01.893357Z","published":"2025-09-17T14:56:32.302Z","related":["SUSE-SU-2025:03600-1","SUSE-SU-2025:03634-1","SUSE-SU-2025:20851-1","SUSE-SU-2025:20861-1","SUSE-SU-2025:20870-1","SUSE-SU-2025:20898-1","SUSE-SU-2025:3751-1","SUSE-SU-2025:4057-1","SUSE-SU-2025:4132-1","SUSE-SU-2025:4141-1","SUSE-SU-2025:4189-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53338.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/065d5f17096ec9161180e2c890afdff4dc6125f2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/29b22badb7a84b783e3a4fffca16f7768fb31205"},{"type":"WEB","url":"https://git.kernel.org/stable/c/65583f9e070db7bece20710cfa2e3daeb0b831d9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/67f8f2bae8e7ac72e09def2b667e44704c4d1ee1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a97f221651fcdc891166e9bc270e3d9bfa5a0080"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d68c17402442f5f494a2c3ebde5cb82f6aa9160a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e3f647e4b642f9f6d32795a16f92c116c138d2af"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53338.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-53338"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2"},{"fixed":"67f8f2bae8e7ac72e09def2b667e44704c4d1ee1"},{"fixed":"a97f221651fcdc891166e9bc270e3d9bfa5a0080"},{"fixed":"e3f647e4b642f9f6d32795a16f92c116c138d2af"},{"fixed":"065d5f17096ec9161180e2c890afdff4dc6125f2"},{"fixed":"d68c17402442f5f494a2c3ebde5cb82f6aa9160a"},{"fixed":"65583f9e070db7bece20710cfa2e3daeb0b831d9"},{"fixed":"29b22badb7a84b783e3a4fffca16f7768fb31205"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-53338.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}