{"id":"CVE-2026-99138","aliases":[],"title":"tcp: fix use-after-free in do_tcp_getsockopt(TCP_CC_INFO)","titleSource":"Linux","descriptionSource":"Linux","products":[{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"86814e5370068ec2bf0caa6e6d55c3e5bfc6c324","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"39aa489e85752f9de214edb0f85e4d578e57af29","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"385e474086c2e7e29e2dded690be40dc273e20ee","versionType":"git"}],"defaultStatus":"unaffected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99138"},{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"5.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.6","versionType":"semver"},{"version":"6.18.59","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.13","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"defaultStatus":"affected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99138"}],"remediation":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: fix use-after-free in do_tcp_getsockopt(TCP_CC_INFO)\n\ndo_tcp_getsockopt() reads icsk->icsk_ca_ops and dereferences the\nget_info function pointer without rcu_read_lock(). With BPF struct_ops\ncongestion control, ca_ops can point to dynamically allocated memory\nthat is freed concurrently, resulting in a use-after-free when the\nkernel dereferences or calls through the stale pointer.\n\n  BUG: KASAN: slab-use-after-free in do_tcp_getsockopt+0x2037/0x23e0\n  Read of size 8 at addr ffff888013701258 by task exploit/149\n   do_tcp_getsockopt+0x2037/0x23e0 (net/ipv4/tcp.c:4564)\n   tcp_getsockopt+0x91/0xf0\n   __sys_getsockopt+0xf7/0x170\n\nFix this by wrapping the ca_ops load and get_info call within\nrcu_read_lock()/rcu_read_unlock(), and using READ_ONCE() to load\nthe icsk_ca_ops pointer.","severity":"unknown","score":null,"published":"2026-10-28T10:34:49.993Z","modified":"2026-10-28T10:34:49.993Z","withdrawn":false,"knownExploited":false,"affected":[],"references":["https://git.kernel.org/stable/c/86814e5370068ec2bf0caa6e6d55c3e5bfc6c324","https://git.kernel.org/stable/c/39aa489e85752f9de214edb0f85e4d578e57af29","https://git.kernel.org/stable/c/385e474086c2e7e29e2dded690be40dc273e20ee"],"sources":[{"name":"CVE","id":"CVE-2026-99138","modified":"2026-10-28T10:34:49.993Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-99138"}],"assessments":[],"sourceAffected":[],"kev":{"status":"not-listed","checkedAt":"2026-10-29T03:15:31.428Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[]}