{"id":"CVE-2026-98643","revision":"4b3655cc6cf4421ca1b4023ce2539ec9","records":[{"revision":"4b3655cc6cf4421ca1b4023ce2539ec9","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98643","aliases":[],"title":"bpf: Fix out-of-bounds read of rtt_min in sock_ops","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix out-of-bounds read of rtt_min in sock_ops\n\nA sockops prog reading skops->rtt_min never checks the sk type: on the\ntcp_conn_request() path sock_ops->sk is a request_sock (non-full), and the\nctx rewrite casts it to a tcp_sock (full) and reads rtt_min past the end of\nthe request_sock, returning dirty adjacent memory.\n\n\tSEC(\"sockops\")\n\tint prog(struct bpf_sock_ops *skops)\n\t{\n\t\tswitch (skops->op) {\n\t\tcase BPF_SOCK_OPS_RWND_INIT:\n\t\t\tleak = skops->rtt_min;   /* reads the request_sock OOB */\n\t\t...\n\t\t}\n\t}\n\nFor instance one such read returned rtt_min=0xffff8881, the high half of a\nleaked kernel pointer.\n\nGuarding that cast is exactly what SOCK_OPS_GET_FIELD() does -- it checks\nis_locked_tcp_sock and returns 0 when sock_ops->sk is not a locked full\nsocket. Every other tcp_sock field in sock_ops goes through it; rtt_min is\nthe only one open-coded, so it skips the check.\n\nRead rtt_min through SOCK_OPS_GET_FIELD() too. rtt_min is a bit special:\nit is a struct minmax and we only want the current min, so pass\nrtt_min.s[0].v. That is equivalent to the old hand-computed offset\n\n\toffsetof(struct tcp_sock, rtt_min) + sizeof_field(struct minmax_sample, t)\n\n(s[0] sits at rtt_min + 0 and .v at + sizeof(.t), i.e. what minmax_get()\nreturns), so the loaded field is unchanged and only the full-sock guard is\nadded. The two BUILD_BUG_ON()s that protected the hand-computed offset\nare no longer needed.\n\nBefore patch:\n\n\t0: r1 = *(u64 *)(r1 +0)      ; r1 = skops->sk\n\t1: r1 = *(u32 *)(r1 +2324)   ; ((tcp_sock *)sk)->rtt_min.s[0].v\n\nAfter patch:\n\n\t0: *(u64 *)(r1 +56) = r9\n\t1: r9 = *(u8 *)(r1 +50)      ; is_locked_tcp_sock\n\t2: if r9 == 0 goto pc+4      ; not a locked full sock -> 0\n\t3: r9 = *(u64 *)(r1 +56)\n\t4: r1 = *(u64 *)(r1 +0)      ; r1 = skops->sk\n\t5: r1 = *(u32 *)(r1 +2324)   ; rtt_min.s[0].v\n\t6: goto pc+2\n\t7: r9 = *(u64 *)(r1 +56)\n\t8: r1 = 0","state":0,"publishedAt":"2026-10-18T15:20:14.561+00:00","modifiedAt":"2026-10-19T09:23:12.946+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/core/filter.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"44f0e43037d3a17b043843ba67610ac7c7e37db6\",\n                            \"lessThan\": \"0c796efa919f52f788c22c79d1f1b70321696b3d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"44f0e43037d3a17b043843ba67610ac7c7e37db6\",\n                            \"lessThan\": \"fc9d0e6e9d86fbefe7b8fe6ee49f4cf102add79d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"44f0e43037d3a17b043843ba67610ac7c7e37db6\",\n                            \"lessThan\": \"fd6bf2721933d8c90bc4ce57f3e204c9295e7e3f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"44f0e43037d3a17b043843ba67610ac7c7e37db6\",\n                            \"lessThan\": \"a8a9becbac93a9f54f4d565f1f3005eb08a7912f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"44f0e43037d3a17b043843ba67610ac7c7e37db6\",\n                            \"lessThan\": \"3a46f14e6cf375f3ca38f8f6e6524749e24ea0a8\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"44f0e43037d3a17b043843ba67610ac7c7e37db6\",\n                            \"lessThan\": \"6785313d4fac96afb21ef193610c1fa88b1a9e64\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"44f0e43037d3a17b043843ba67610ac7c7e37db6\",\n                            \"lessThan\": \"cba54d142c43ec96d8c4d566f66439e8c0afded7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"44f0e43037d3a17b043843ba67610ac7c7e37db6\",\n                            \"lessThan\": \"75f8cf22463d82bb1fb0239a3d485fc8f4c8ef03\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/core/filter.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.16\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.16\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.271\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.222\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.189\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.158\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.112\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.55\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.9\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/0c796efa919f52f788c22c79d1f1b70321696b3d","https://git.kernel.org/stable/c/fc9d0e6e9d86fbefe7b8fe6ee49f4cf102add79d","https://git.kernel.org/stable/c/fd6bf2721933d8c90bc4ce57f3e204c9295e7e3f","https://git.kernel.org/stable/c/a8a9becbac93a9f54f4d565f1f3005eb08a7912f","https://git.kernel.org/stable/c/3a46f14e6cf375f3ca38f8f6e6524749e24ea0a8","https://git.kernel.org/stable/c/6785313d4fac96afb21ef193610c1fa88b1a9e64","https://git.kernel.org/stable/c/cba54d142c43ec96d8c4d566f66439e8c0afded7","https://git.kernel.org/stable/c/75f8cf22463d82bb1fb0239a3d485fc8f4c8ef03"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98643","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98643","identifiers":["CVE-2026-98643"]},"retained":false,"historicalAffected":[]}],"coverage":[]}