{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "8e04ce45a8db7a080220e86e249198fa676b83dc"
            },
            {
              "fixed": "58b58b9ba89c43914eea90c18928e51852d10c24"
            },
            {
              "fixed": "de3c248d1b69eaefa2d5b3da4005936dcf590f1b"
            },
            {
              "fixed": "5dd8025a49c268ab6b94d978532af3ad341132a7"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "49888b3b457b801282b44c246d289c56e2f2a55b"
            },
            {
              "last_affected": "0206a9341e652167c610dcd79f3d4e9e8153984c"
            },
            {
              "last_affected": "7d6d10eee01edc9c20850ea75cf8273dc1170921"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "6.6.117"
            },
            {
              "fixed": "6.7"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "6.12.59"
            },
            {
              "fixed": "6.13"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "6.17.8"
            },
            {
              "fixed": "6.18"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.18.0"
            },
            {
              "fixed": "6.18.22"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43029.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix soft lockup in mptcp_recvmsg()\n\nsyzbot reported a soft lockup in mptcp_recvmsg() [0].\n\nWhen receiving data with MSG_PEEK | MSG_WAITALL flags, the skb is not\nremoved from the sk_receive_queue. This causes sk_wait_data() to always\nfind available data and never perform actual waiting, leading to a soft\nlockup.\n\nFix this by adding a 'last' parameter to track the last peeked skb.\nThis allows sk_wait_data() to make informed waiting decisions and prevent\ninfinite loops when MSG_PEEK is used.\n\n[0]:\nwatchdog: BUG: soft lockup - CPU#2 stuck for 156s! [server:1963]\nModules linked in:\nCPU: 2 UID: 0 PID: 1963 Comm: server Not tainted 6.19.0-rc8 #61 PREEMPT(none)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\nRIP: 0010:sk_wait_data+0x15/0x190\nCode: 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 56 41 55 41 54 49 89 f4 55 48 89 d5 53 48 89 fb \u003c48\u003e 83 ec 30 65 48 8b 05 17 a4 6b 01 48 89 44 24 28 31 c0 65 48 8b\nRSP: 0018:ffffc90000603ca0 EFLAGS: 00000246\nRAX: 0000000000000000 RBX: ffff888102bf0800 RCX: 0000000000000001\nRDX: 0000000000000000 RSI: ffffc90000603d18 RDI: ffff888102bf0800\nRBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000000101\nR10: 0000000000000000 R11: 0000000000000075 R12: ffffc90000603d18\nR13: ffff888102bf0800 R14: ffff888102bf0800 R15: 0000000000000000\nFS:  00007f6e38b8c4c0(0000) GS:ffff8881b877e000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 000055aa7bff1680 CR3: 0000000105cbe000 CR4: 00000000000006f0\nCall Trace:\n \u003cTASK\u003e\n mptcp_recvmsg+0x547/0x8c0 net/mptcp/protocol.c:2329\n inet_recvmsg+0x11f/0x130 net/ipv4/af_inet.c:891\n sock_recvmsg+0x94/0xc0 net/socket.c:1100\n __sys_recvfrom+0xb2/0x130 net/socket.c:2256\n __x64_sys_recvfrom+0x1f/0x30 net/socket.c:2267\n do_syscall_64+0x59/0x2d0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x76/0x7e arch/x86/entry/entry_64.S:131\nRIP: 0033:0x7f6e386a4a1d\nCode: 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 8d 05 f1 de 2c 00 41 89 ca 8b 00 85 c0 75 20 45 31 c9 45 31 c0 b8 2d 00 00 00 0f 05 \u003c48\u003e 3d 00 f0 ff ff 77 6b f3 c3 66 0f 1f 84 00 00 00 00 00 41 56 41\nRSP: 002b:00007ffc3c4bb078 EFLAGS: 00000246 ORIG_RAX: 000000000000002d\nRAX: ffffffffffffffda RBX: 000000000000861e RCX: 00007f6e386a4a1d\nRDX: 00000000000003ff RSI: 00007ffc3c4bb150 RDI: 0000000000000004\nRBP: 00007ffc3c4bb570 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000103 R11: 0000000000000246 R12: 00005605dbc00be0\nR13: 00007ffc3c4bb650 R14: 0000000000000000 R15: 0000000000000000\n \u003c/TASK\u003e",
  "id": "CVE-2026-43029",
  "modified": "2026-07-15T01:49:21.494651241Z",
  "published": "2026-05-01T14:15:29.885Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/58b58b9ba89c43914eea90c18928e51852d10c24"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5dd8025a49c268ab6b94d978532af3ad341132a7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/de3c248d1b69eaefa2d5b3da4005936dcf590f1b"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43029.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43029"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "mptcp: fix soft lockup in mptcp_recvmsg()"
}