{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2024-26782",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2024-26782"
  ],
  "published": "2024-04-04T08:23:56Z",
  "summary": "mptcp: fix double-free on socket dismantle",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix double-free on socket dismantle\n\nwhen MPTCP server accepts an incoming connection, it clones its listener\nsocket. However, the pointer to 'inet_opt' for the new socket has the same\nvalue as the original one: as a consequence, on program exit it's possible\nto observe the following splat:\n\n  BUG: KASAN: double-free in inet_sock_destruct+0x54f/0x8b0\n  Free of addr ffff888485950880 by task swapper/25/0\n\n  CPU: 25 PID: 0 Comm: swapper/25 Kdump: loaded Not tainted 6.8.0-rc1+ #609\n  Hardware name: Supermicro SYS-6027R-72RF/X9DRH-7TF/7F/iTF/iF, BIOS 3.0  07/26/2013\n  Call Trace:\n   <IRQ>\n   dump_stack_lvl+0x32/0x50\n   print_report+0xca/0x620\n   kasan_report_invalid_free+0x64/0x90\n   __kasan_slab_free+0x1aa/0x1f0\n   kfree+0xed/0x2e0\n   inet_sock_destruct+0x54f/0x8b0\n   __sk_destruct+0x48/0x5b0\n   rcu_do_batch+0x34e/0xd90\n   rcu_core+0x559/0xac0\n   __do_softirq+0x183/0x5a4\n   irq_exit_rcu+0x12d/0x170\n   sysvec_apic_timer_interrupt+0x6b/0x80\n   </IRQ>\n   <TASK>\n   asm_sysvec_apic_timer_interrupt+0x16/0x20\n  RIP: 0010:cpuidle_enter_state+0x175/0x300\n  Code: 30 00 0f 84 1f 01 00 00 83 e8 01 83 f8 ff 75 e5 48 83 c4 18 44 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc fb 45 85 ed <0f> 89 60 ff ff ff 48 c1 e5 06 48 c7 43 18 00 00 00 00 48 83 44 2b\n  RSP: 0018:ffff888481cf7d90 EFLAGS: 00000202\n  RAX: 0000000000000000 RBX: ffff88887facddc8 RCX: 0000000000000000\n  RDX: 1ffff1110ff588b1 RSI: 0000000000000019 RDI: ffff88887fac4588\n  RBP: 0000000000000004 R08: 0000000000000002 R09: 0000000000043080\n  R10: 0009b02ea273363f R11: ffff88887fabf42b R12: ffffffff932592e0\n  R13: 0000000000000004 R14: 0000000000000000 R15: 00000022c880ec80\n   cpuidle_enter+0x4a/0xa0\n   do_idle+0x310/0x410\n   cpu_startup_entry+0x51/0x60\n   start_secondary+0x211/0x270\n   secondary_startup_64_no_verify+0x184/0x18b\n   </TASK>\n\n  Allocated by task 6853:\n   kasan_save_stack+0x1c/0x40\n   kasan_save_track+0x10/0x30\n   __kasan_kmalloc+0xa6/0xb0\n   __kmalloc+0x1eb/0x450\n   cipso_v4_sock_setattr+0x96/0x360\n   netlbl_sock_setattr+0x132/0x1f0\n   selinux_netlbl_socket_post_create+0x6c/0x110\n   selinux_socket_post_create+0x37b/0x7f0\n   security_socket_post_create+0x63/0xb0\n   __sock_create+0x305/0x450\n   __sys_socket_create.part.23+0xbd/0x130\n   __sys_socket+0x37/0xb0\n   __x64_sys_socket+0x6f/0xb0\n   do_syscall_64+0x83/0x160\n   entry_SYSCALL_64_after_hwframe+0x6e/0x76\n\n  Freed by task 6858:\n   kasan_save_stack+0x1c/0x40\n   kasan_save_track+0x10/0x30\n   kasan_save_free_info+0x3b/0x60\n   __kasan_slab_free+0x12c/0x1f0\n   kfree+0xed/0x2e0\n   inet_sock_destruct+0x54f/0x8b0\n   __sk_destruct+0x48/0x5b0\n   subflow_ulp_release+0x1f0/0x250\n   tcp_cleanup_ulp+0x6e/0x110\n   tcp_v4_destroy_sock+0x5a/0x3a0\n   inet_csk_destroy_sock+0x135/0x390\n   tcp_fin+0x416/0x5c0\n   tcp_data_queue+0x1bc8/0x4310\n   tcp_rcv_state_process+0x15a3/0x47b0\n   tcp_v4_do_rcv+0x2c1/0x990\n   tcp_v4_rcv+0x41fb/0x5ed0\n   ip_protocol_deliver_rcu+0x6d/0x9f0\n   ip_local_deliver_finish+0x278/0x360\n   ip_local_deliver+0x182/0x2c0\n   ip_rcv+0xb5/0x1c0\n   __netif_receive_skb_one_core+0x16e/0x1b0\n   process_backlog+0x1e3/0x650\n   __napi_poll+0xa6/0x500\n   net_rx_action+0x740/0xbb0\n   __do_softirq+0x183/0x5a4\n\n  The buggy address belongs to the object at ffff888485950880\n   which belongs to the cache kmalloc-64 of size 64\n  The buggy address is located 0 bytes inside of\n   64-byte region [ffff888485950880, ffff8884859508c0)\n\n  The buggy address belongs to the physical page:\n  page:0000000056d1e95e refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888485950700 pfn:0x485950\n  flags: 0x57ffffc0000800(slab|node=1|zone=2|lastcpupid=0x1fffff)\n  page_type: 0xffffffff()\n  raw: 0057ffffc0000800 ffff88810004c640 ffffea00121b8ac0 dead000000000006\n  raw: ffff888485950700 0000000000200019 00000001ffffffff 0000000000000000\n  page dumped because: kasan: bad access detected\n\n  Memory state around the buggy address:\n   ffff888485950780: fa fb fb\n---truncated---",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt2",
        "1:6.1.47-1+rpt4",
        "1:6.1.54-1+rpt2",
        "1:6.1.58-1+rpt2",
        "1:6.1.63-1+rpt1",
        "1:6.1.73-1+rpt1",
        "1:6.6.20-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi2-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi4-rpi-2712",
            "binary_version": "1:6.1.54-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi4-rpi-v8",
            "binary_version": "1:6.1.54-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi6-rpi-2712",
            "binary_version": "1:6.1.58-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi6-rpi-v8",
            "binary_version": "1:6.1.58-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi7-rpi-2712",
            "binary_version": "1:6.1.63-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi7-rpi-v8",
            "binary_version": "1:6.1.63-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi8-rpi-2712",
            "binary_version": "1:6.1.73-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi8-rpi-v8",
            "binary_version": "1:6.1.73-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.20+rpt-rpi-2712",
            "binary_version": "1:6.6.20-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.20+rpt-rpi-v8",
            "binary_version": "1:6.6.20-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt2": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.81"
          },
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.81",
            "compiled_filter": false
          },
          "1:6.1.54-1+rpt2": {
            "linux_commit": "2906f7abdc03d4a92b6b0e2e0c87ea2a9dffe8f7",
            "upstream_version": "6.1.54",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.81"
          },
          "1:6.1.58-1+rpt2": {
            "linux_commit": "ccf1586ad0663fa91238ac56abf6340d6d740d18",
            "upstream_version": "6.1.58",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.81"
          },
          "1:6.1.63-1+rpt1": {
            "linux_commit": null,
            "upstream_version": "6.1.63",
            "assessment": "upstream version (no usable Linux commit)",
            "upstream_fixed": "6.1.81"
          },
          "1:6.1.73-1+rpt1": {
            "linux_commit": null,
            "upstream_version": "6.1.73",
            "assessment": "upstream version (no usable Linux commit)",
            "upstream_fixed": "6.1.81"
          },
          "1:6.6.20-1+rpt1": {
            "linux_commit": "6f16847710cc0502450788b9f12f0a14d3429668",
            "upstream_version": "6.6.20",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.21"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2024-26782"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f74362a004225df935863dea6eb7d82daaa5b16e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/4a4eeb6912538c2d0b158e8d11b62d96c1dada4e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d93fd40c62397326046902a2c5cb75af50882a85"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ce0809ada38dca8d6d41bb57ab40494855c30582"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/85933e80d077c9ae2227226beb86c22f464059cc"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/10048689def7e40a4405acda16fdc6477d4ecc5c"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T11:52:36Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 9.8,
      "cvss_v3_severity": "Critical",
      "scenario": "AV:N - The vulnerable clone occurs in `subflow_syn_recv_sock()` during softirq processing of a received MPTCP third-ACK (ip_rcv \u2192 tcp_v4_rcv \u2192 tcp_check_req), so any remote host able to reach the MPTCP listening port triggers it. Both the aliasing and the subsequent frees are driven entirely by attacker-sent packets.\nAC:L - On an MPTCP server with NetLabel/CIPSO labeling (the shipped SELinux-MLS/Smack configuration in which this was reported), every completed MP_CAPABLE handshake deterministically clones the shared pointer, and each connection teardown frees it again \u2014 no race, no memory-layout dependency, and the attacker can repeat the connect/close cycle arbitrarily to control allocation interleaving.\nPR:N - The clone happens in the kernel's SYN-recv path before `accept()` and before any application-level authentication, so the attacker needs no credentials on the target at all. The listening socket is set up by the victim service, not by the attacker.\nUI:N - No victim action is needed beyond the MPTCP service already listening; the attacker completes the handshake and closes connections on its own.\nS:U - The corruption is confined to the kernel's own slab allocator within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The double free (and the IPv6 `ipv6_txoptions` refcount underflow) causes two live kernel objects to alias the same kmalloc-64 region, a well-known route to type confusion and arbitrary kernel-memory disclosure. Per kernel scoring guidance, use-after-free/double-free is scored High.\nI:H - Repeated frees of a still-referenced object corrupt the SLUB freelist, giving heap-spray and arbitrary-write primitives that can be leveraged for control-flow hijack and privilege escalation. The attacker can invoke the free primitive an unbounded number of times remotely.\nA:H - Even unweaponized, the double free produces slab corruption, a KASAN `kasan_report_invalid_free` BUG, or a kernel panic (the reported splat occurs in an RCU softirq callback), crashing the machine."
    }
  }
}