{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-21875", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.781Z", "datePublished": "2025-03-27T14:57:06.154Z", "dateUpdated": "2026-08-05T11:55:02.613Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:55:02.613Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: always handle address removal under msk socket lock\n\nSyzkaller reported a lockdep splat in the PM control path:\n\n WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 sock_owned_by_me include/net/sock.h:1711 [inline]\n WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 msk_owned_by_me net/mptcp/protocol.h:363 [inline]\n WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 mptcp_pm_nl_addr_send_ack+0x57c/0x610 net/mptcp/pm_netlink.c:788\n Modules linked in:\n CPU: 0 UID: 0 PID: 6693 Comm: syz.0.205 Not tainted 6.14.0-rc2-syzkaller-00303-gad1b832bf1cf #0\n Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024\n RIP: 0010:sock_owned_by_me include/net/sock.h:1711 [inline]\n RIP: 0010:msk_owned_by_me net/mptcp/protocol.h:363 [inline]\n RIP: 0010:mptcp_pm_nl_addr_send_ack+0x57c/0x610 net/mptcp/pm_netlink.c:788\n Code: 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 ca 7b d3 f5 eb b9 e8 c3 7b d3 f5 90 0f 0b 90 e9 dd fb ff ff e8 b5 7b d3 f5 90 <0f> 0b 90 e9 3e fb ff ff 44 89 f1 80 e1 07 38 c1 0f 8c eb fb ff ff\n RSP: 0000:ffffc900034f6f60 EFLAGS: 00010283\n RAX: ffffffff8bee3c2b RBX: 0000000000000001 RCX: 0000000000080000\n RDX: ffffc90004d42000 RSI: 000000000000a407 RDI: 000000000000a408\n RBP: ffffc900034f7030 R08: ffffffff8bee37f6 R09: 0100000000000000\n R10: dffffc0000000000 R11: ffffed100bcc62e4 R12: ffff88805e6316e0\n R13: ffff88805e630c00 R14: dffffc0000000000 R15: ffff88805e630c00\n FS: 00007f7e9a7e96c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 0000001b2fd18ff8 CR3: 0000000032c24000 CR4: 00000000003526f0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n Call Trace:\n \n mptcp_pm_remove_addr+0x103/0x1d0 net/mptcp/pm.c:59\n mptcp_pm_remove_anno_addr+0x1f4/0x2f0 net/mptcp/pm_netlink.c:1486\n mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_netlink.c:1518 [inline]\n mptcp_pm_nl_del_addr_doit+0x118d/0x1af0 net/mptcp/pm_netlink.c:1629\n genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]\n genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]\n genl_rcv_msg+0xb1f/0xec0 net/netlink/genetlink.c:1210\n netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2543\n genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219\n netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]\n netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348\n netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1892\n sock_sendmsg_nosec net/socket.c:718 [inline]\n __sock_sendmsg+0x221/0x270 net/socket.c:733\n ____sys_sendmsg+0x53a/0x860 net/socket.c:2573\n ___sys_sendmsg net/socket.c:2627 [inline]\n __sys_sendmsg+0x269/0x350 net/socket.c:2659\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n RIP: 0033:0x7f7e9998cde9\n Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48\n RSP: 002b:00007f7e9a7e9038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e\n RAX: ffffffffffffffda RBX: 00007f7e99ba5fa0 RCX: 00007f7e9998cde9\n RDX: 000000002000c094 RSI: 0000400000000000 RDI: 0000000000000007\n RBP: 00007f7e99a0e2a0 R08: 0000000000000000 R09: 0000000000000000\n R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\n R13: 0000000000000000 R14: 00007f7e99ba5fa0 R15: 00007fff49231088\n\nIndeed the PM can try to send a RM_ADDR over a msk without acquiring\nfirst the msk socket lock.\n\nThe bugged code-path comes from an early optimization: when there\nare no subflows, the PM should (usually) not send RM_ADDR\nnotifications.\n\nThe above statement is incorrect, as without locks another process\ncould concur\n---truncated---" } ], "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 vulnerability is triggered by the MPTCP_PM_CMD_DEL_ADDR generic-netlink command (`mptcp_pm_nl_del_addr_doit`), which requires a local AF_NETLINK socket; the racing subflow churn is likewise driven locally over loopback. No remote peer can reach this path on its own.\nAC:L - The attacker controls both sides of the race — one thread spams DEL_ADDR/ADD_ADDR netlink commands while another creates and tears down MPTCP subflows in the same namespace, both in tight loops. Syzkaller hit it by blind fuzzing, and no special configuration is required since kernel PM and MPTCP are enabled by default.\nPR:L - MPTCP_PM_CMD_DEL_ADDR carries GENL_UNS_ADMIN_PERM, enforced as `netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)`, which any unprivileged user obtains via `unshare -Urn`; MPTCP socket creation and the token iterator are per-netns and need no privilege.\nUI:N - The attacker drives both the netlink command and the subflow lifecycle entirely from their own processes. No victim action is involved.\nS:U - The corruption is confined to kernel memory within the same security authority; there is no VM, IOMMU, or sandbox boundary crossed.\nC:H - The unlocked `mptcp_for_each_subflow()` walk reads `struct mptcp_subflow_context` fields (including `tcp_sock`) from memory that a concurrent `__mptcp_close_ssk()` may have freed, and the netlink path holds no RCU read lock to defer the `kfree_rcu`. A use-after-free over a heap-groomable object gives attacker-influenced read of kernel memory.\nI:H - The stale `subflow->tcp_sock` pointer is passed to `lock_sock_fast()` and `__mptcp_subflow_send_ack()`, producing writes through a freed/reallocated object; the concurrent `list_del`/`list_add_tail` against an unsynchronized traversal additionally corrupts the conn_list linkage.\nA:H - The reported symptom is a `sock_owned_by_me()` WARN, which panics outright on `panic_on_warn` systems, and following a `LIST_POISON1` pointer or a freed subflow context oopses the kernel. Any use-after-free of this kind reliably crashes the machine." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/mptcp/pm_netlink.c" ], "versions": [ { "version": "b6c08380860b926752d57c8fa9911fa388c4b876", "lessThan": "494ec285535632732eaa5786297a9ae4f731b5ff", "status": "affected", "versionType": "git" }, { "version": "b6c08380860b926752d57c8fa9911fa388c4b876", "lessThan": "7cca31035c05819643ffb5d7518e9a331b3f6651", "status": "affected", "versionType": "git" }, { "version": "b6c08380860b926752d57c8fa9911fa388c4b876", "lessThan": "8116fb4acd5d3f06cd37f84887dbe962b6703b1c", "status": "affected", "versionType": "git" }, { "version": "b6c08380860b926752d57c8fa9911fa388c4b876", "lessThan": "a05da2be18aae7e82572f8d795f41bb49f5dfc7d", "status": "affected", "versionType": "git" }, { "version": "b6c08380860b926752d57c8fa9911fa388c4b876", "lessThan": "4124b782ec2b1e2e490cf0bbf10f53dfd3479890", "status": "affected", "versionType": "git" }, { "version": "b6c08380860b926752d57c8fa9911fa388c4b876", "lessThan": "2c3de6dff4373f1036e003f49a32629359530bdb", "status": "affected", "versionType": "git" }, { "version": "b6c08380860b926752d57c8fa9911fa388c4b876", "lessThan": "f865c24bc55158313d5779fc81116023a6940ca3", "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/pm_netlink.c" ], "versions": [ { "version": "5.10", "status": "affected" }, { "version": "0", "lessThan": "5.10", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.235", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.179", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.130", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.81", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.18", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.6", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14", "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": "5.10", "versionEndExcluding": "5.10.235" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "5.15.179" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.1.130" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.6.81" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.12.18" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.13.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/494ec285535632732eaa5786297a9ae4f731b5ff" }, { "url": "https://git.kernel.org/stable/c/7cca31035c05819643ffb5d7518e9a331b3f6651" }, { "url": "https://git.kernel.org/stable/c/8116fb4acd5d3f06cd37f84887dbe962b6703b1c" }, { "url": "https://git.kernel.org/stable/c/a05da2be18aae7e82572f8d795f41bb49f5dfc7d" }, { "url": "https://git.kernel.org/stable/c/4124b782ec2b1e2e490cf0bbf10f53dfd3479890" }, { "url": "https://git.kernel.org/stable/c/2c3de6dff4373f1036e003f49a32629359530bdb" }, { "url": "https://git.kernel.org/stable/c/f865c24bc55158313d5779fc81116023a6940ca3" } ], "title": "mptcp: always handle address removal under msk socket lock", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:38:31.794Z" } }, { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:40:25.697Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html" } ] } ] } }