{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-35894", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-17T13:50:33.113Z", "datePublished": "2024-05-19T08:34:49.504Z", "dateUpdated": "2026-08-05T11:30:46.642Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:30:46.642Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: prevent BPF accessing lowat from a subflow socket.\n\nAlexei reported the following splat:\n\n WARNING: CPU: 32 PID: 3276 at net/mptcp/subflow.c:1430 subflow_data_ready+0x147/0x1c0\n Modules linked in: dummy bpf_testmod(O) [last unloaded: bpf_test_no_cfi(O)]\n CPU: 32 PID: 3276 Comm: test_progs Tainted: GO 6.8.0-12873-g2c43c33bfd23\n Call Trace:\n \n mptcp_set_rcvlowat+0x79/0x1d0\n sk_setsockopt+0x6c0/0x1540\n __bpf_setsockopt+0x6f/0x90\n bpf_sock_ops_setsockopt+0x3c/0x90\n bpf_prog_509ce5db2c7f9981_bpf_test_sockopt_int+0xb4/0x11b\n bpf_prog_dce07e362d941d2b_bpf_test_socket_sockopt+0x12b/0x132\n bpf_prog_348c9b5faaf10092_skops_sockopt+0x954/0xe86\n __cgroup_bpf_run_filter_sock_ops+0xbc/0x250\n tcp_connect+0x879/0x1160\n tcp_v6_connect+0x50c/0x870\n mptcp_connect+0x129/0x280\n __inet_stream_connect+0xce/0x370\n inet_stream_connect+0x36/0x50\n bpf_trampoline_6442491565+0x49/0xef\n inet_stream_connect+0x5/0x50\n __sys_connect+0x63/0x90\n __x64_sys_connect+0x14/0x20\n\nThe root cause of the issue is that bpf allows accessing mptcp-level\nproto_ops from a tcp subflow scope.\n\nFix the issue detecting the problematic call and preventing any action." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable path is entered from a local syscall — `connect()`/`listen()` on an `IPPROTO_MPTCP` socket triggers the cgroup sock_ops hook on the grafted subflow before any packet is exchanged. No remote peer data is required to reach `mptcp_set_rcvlowat()` with the wrong sock type.\nAC:L - The type confusion is deterministic — no race and no memory-layout guessing is needed to reach it; creating an MPTCP socket and connecting reproduces it every time (as the BPF selftest did). Attack-relevant heap state (subflow send queue contents) is itself attacker-controlled.\nPR:L - On a realistic container/Kubernetes host that already has an administrator-installed cgroup sock_ops BPF program adjusting socket options, an ordinary unprivileged user needs no capability at all: `socket(AF_INET, SOCK_STREAM, IPPROTO_MPTCP)` requires no privilege and `connect()` drives the confusion.\nUI:N - The attacker triggers the bug entirely through their own syscalls on their own socket. No action by any other user or administrator is needed at exploitation time.\nS:U - The corruption stays within the kernel's own security authority — there is no VM, IOMMU, or sandbox boundary crossed. This is a standard in-kernel type confusion.\nC:H - Type confusion between `struct mptcp_sock` and `struct tcp_sock` causes pointers to be synthesized from unrelated socket memory and dereferenced, and the resulting `sk_rcvbuf`/`window_clamp` corruption at attacker-influenced addresses can be groomed into a read primitive. Per kernel scoring guidance, memory corruption leveragable for disclosure is High.\nI:H - `mptcp_for_each_subflow()` iterates a list head read out of type-confused memory and performs `WRITE_ONCE(ssk->sk_rcvbuf, space)` plus `tcp_sk(ssk)->window_clamp = val` through the resulting wild pointer, giving two 32-bit writes with attacker-influenced values at attacker-influenceable addresses — a control-flow-hijack-capable primitive.\nA:H - The confusion reliably produces a kernel oops: `do_div()` on the aliased `scaling_ratio` byte faults if it reads zero, and `lock_sock_fast()` on the bogus subflow pointer (typically a timestamp-derived non-canonical address) causes a general protection fault, plus the reported `WARN_ON_ONCE` panics under `panic_on_warn`." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/mptcp/sockopt.c" ], "versions": [ { "version": "124a4885b55f3039c697feb53edc5ad88bf21161", "lessThan": "ee3c845787b621cfe82c2e52c513024a9d7a78f5", "status": "affected", "versionType": "git" }, { "version": "5684ab1a0effbfeb706f47d85785f653005b97b1", "lessThan": "3ffb1ab698376f09cc33101c07c1be229389fe29", "status": "affected", "versionType": "git" }, { "version": "5684ab1a0effbfeb706f47d85785f653005b97b1", "lessThan": "fcf4692fa39e86a590c14a4af2de704e1d20a3b5", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/mptcp/sockopt.c" ], "versions": [ { "version": "6.7", "status": "affected" }, { "version": "0", "lessThan": "6.7", "status": "unaffected", "versionType": "semver" }, { "version": "6.8.5", "lessThanOrEqual": "6.8.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.9", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.8.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.9" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ee3c845787b621cfe82c2e52c513024a9d7a78f5" }, { "url": "https://git.kernel.org/stable/c/3ffb1ab698376f09cc33101c07c1be229389fe29" }, { "url": "https://git.kernel.org/stable/c/fcf4692fa39e86a590c14a4af2de704e1d20a3b5" } ], "title": "mptcp: prevent BPF accessing lowat from a subflow socket.", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CISA ADP Vulnrichment", "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2024-35894", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-05-23T17:19:11.932851Z" } } } ], "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-04T17:34:48.035Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/3ffb1ab698376f09cc33101c07c1be229389fe29", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/fcf4692fa39e86a590c14a4af2de704e1d20a3b5", "tags": [ "x_transferred" ] }, { "url": "https://security.netapp.com/advisory/ntap-20250321-0002/" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-03-21T18:03:47.343Z" } } ] } }