{"id":"CVE-2026-99138","title":"tcp: fix use-after-free in do_tcp_getsockopt(TCP_CC_INFO)","summary":"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_l…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2 < 86814e5370068ec2bf0caa6e6d55c3e5bfc6c324","Linux >= 0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2 < 39aa489e85752f9de214edb0f85e4d578e57af29","Linux >= 0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2 < 385e474086c2e7e29e2dded690be40dc273e20ee","Linux 5.6"],"published":"2026-10-28","updated":"2026-10-28","sourceUpdated":"2026-10-28T10:34:49.993Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99138","references":[{"url":"https://git.kernel.org/stable/c/86814e5370068ec2bf0caa6e6d55c3e5bfc6c324"},{"url":"https://git.kernel.org/stable/c/39aa489e85752f9de214edb0f85e4d578e57af29"},{"url":"https://git.kernel.org/stable/c/385e474086c2e7e29e2dded690be40dc273e20ee"}],"tags":["cve.org"],"ingestedAt":"2026-10-28T11:09:40.430Z","slug":"CVE-2026-99138","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= 0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2 < 86814e5370068ec2bf0caa6e6d55c3e5bfc6c324`\n- `Linux >= 0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2 < 39aa489e85752f9de214edb0f85e4d578e57af29`\n- `Linux >= 0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2 < 385e474086c2e7e29e2dded690be40dc273e20ee`\n- `Linux 5.6`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}