{"id":"CVE-2026-99138","state":"PUBLISHED","title":"tcp: fix use-after-free in do_tcp_getsockopt(TCP_CC_INFO)","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.","publishedAt":"2026-10-28T10:34:49.993Z","updatedAt":"2026-10-30T12:42:10.759Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"7c312f17917455eedcea29735fa302ebb93cb9b9","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"66b831b427301a9c3e485564009d476631413103","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"a8b024cbf62b497062c86995737fc303e4cc384e","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"8d5fc9e6dc09174d0da6e59678eb8e01a890cbd3","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"e057d201640eebb8ed47ec924872c41570a3bd28","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"86814e5370068ec2bf0caa6e6d55c3e5bfc6c324","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"39aa489e85752f9de214edb0f85e4d578e57af29","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"385e474086c2e7e29e2dded690be40dc273e20ee","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/tcp.c","net/ipv4/tcp_dctcp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.6","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.161","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.115","status":"unaffected","lessThanOrEqual":"6.12.*","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"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/tcp.c","net/ipv4/tcp_dctcp.c"]}],"references":["https://git.kernel.org/stable/c/7c312f17917455eedcea29735fa302ebb93cb9b9","https://git.kernel.org/stable/c/66b831b427301a9c3e485564009d476631413103","https://git.kernel.org/stable/c/a8b024cbf62b497062c86995737fc303e4cc384e","https://git.kernel.org/stable/c/8d5fc9e6dc09174d0da6e59678eb8e01a890cbd3","https://git.kernel.org/stable/c/e057d201640eebb8ed47ec924872c41570a3bd28","https://git.kernel.org/stable/c/86814e5370068ec2bf0caa6e6d55c3e5bfc6c324","https://git.kernel.org/stable/c/39aa489e85752f9de214edb0f85e4d578e57af29","https://git.kernel.org/stable/c/385e474086c2e7e29e2dded690be40dc273e20ee"],"weaknesses":[],"ingestedAt":"2026-10-30T13:02:04.640Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/99xxx/CVE-2026-99138.json","commit":"cb14bf1b43b0c9f05f7f40eae2246263fd430780","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-99138","state":"PUBLISHED","datePublished":"2026-10-28T10:34:49.993Z","dateUpdated":"2026-10-30T12:42:10.759Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.395Z"},"containers":{"cna":{"title":"tcp: fix use-after-free in do_tcp_getsockopt(TCP_CC_INFO)","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"7c312f17917455eedcea29735fa302ebb93cb9b9","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"66b831b427301a9c3e485564009d476631413103","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"a8b024cbf62b497062c86995737fc303e4cc384e","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"8d5fc9e6dc09174d0da6e59678eb8e01a890cbd3","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"e057d201640eebb8ed47ec924872c41570a3bd28","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"86814e5370068ec2bf0caa6e6d55c3e5bfc6c324","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"39aa489e85752f9de214edb0f85e4d578e57af29","versionType":"git"},{"version":"0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2","status":"affected","lessThan":"385e474086c2e7e29e2dded690be40dc273e20ee","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/tcp.c","net/ipv4/tcp_dctcp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.6","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.161","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.115","status":"unaffected","lessThanOrEqual":"6.12.*","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"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/tcp.c","net/ipv4/tcp_dctcp.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/7c312f17917455eedcea29735fa302ebb93cb9b9"},{"url":"https://git.kernel.org/stable/c/66b831b427301a9c3e485564009d476631413103"},{"url":"https://git.kernel.org/stable/c/a8b024cbf62b497062c86995737fc303e4cc384e"},{"url":"https://git.kernel.org/stable/c/8d5fc9e6dc09174d0da6e59678eb8e01a890cbd3"},{"url":"https://git.kernel.org/stable/c/e057d201640eebb8ed47ec924872c41570a3bd28"},{"url":"https://git.kernel.org/stable/c/86814e5370068ec2bf0caa6e6d55c3e5bfc6c324"},{"url":"https://git.kernel.org/stable/c/39aa489e85752f9de214edb0f85e4d578e57af29"},{"url":"https://git.kernel.org/stable/c/385e474086c2e7e29e2dded690be40dc273e20ee"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:42:10.759Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.6.161"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.12.115"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.18.59"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"7.2.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}