FKIE_CVE-2026-98812

Vulnerability from fkie_nvd - Published: 2026-10-18 16:17 - Updated: 2026-10-30 13:21
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: net/mctp: publish the mctp_dev only after it is initialised mctp_add_dev() links the new mctp_dev into dev->mctp_ptr before mdev->dev is assigned, so a reader that picks the device up in that window dereferences a net_device pointer that is still NULL: KASAN: null-ptr-deref in range [0x00000000000000b0-0x00000000000000b7] Call Trace: <TASK> ? __pfx_mctp_sendmsg (./include/linux/sockptr.h:49) ? __pfx_mctp_dst_output (net/mctp/route.c:41) ? selinux_socket_sendmsg (security/selinux/hooks.c:5278) ____sys_sendmsg (net/socket.c:775 (discriminator 1) net/socket.c:790 (discriminator 1) net/socket.c:2684 (discriminator 1)) ? __pfx_____sys_sendmsg (net/socket.c:1131) ? __pfx_copy_msghdr_from_user (net/socket.c:2590) ? update_cfs_rq_load_avg (kernel/sched/fair.c:5478) ___sys_sendmsg (net/socket.c:2738) ? __pfx____sys_sendmsg (net/socket.c:2625) ? perf_event_task_tick (./include/linux/rcupdate.h:838) ? sched_tick (kernel/sched/core.c:5818) ? clockevents_program_event (kernel/time/clockevents.c:372) ? fdget (./include/linux/rcupdate.h:873 fs/file.c:1100) __sys_sendmsg (net/socket.c:2770) ? __pfx___sys_sendmsg (net/socket.c:2751) do_syscall_64 (arch/x86/entry/syscall_64.c:63) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) </TASK> Fix by publishing only once the object is fully initialised: __mctp_dev_get() runs under rcu_read_lock() only and hands this object to readers as soon as mctp_ptr is assigned, so they must never observe mdev->dev == NULL.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/288ef37e0c463192dbb6436e61cdc07ce666dcb9
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/58a270b5ecd8629114a4754d642bad6a33bef493
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/63120572edde85bb2b70b0ed4d4817ed52247613
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/aadf655e8ea9a8ffa24bb8d69f504572e8d18181
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/af6e4f931afc2d670d133aa2bedc8b6e3753c618
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f37f42e6e039a48c2dcf6c079b9f7fbc864ab7ef
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fdf09d0fa2fb639950bede185d22689f68df140e
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/mctp/device.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "58a270b5ecd8629114a4754d642bad6a33bef493",
              "status": "affected",
              "version": "583be982d93479ea3d85091b0fd0b01201ede87d",
              "versionType": "git"
            },
            {
              "lessThan": "fdf09d0fa2fb639950bede185d22689f68df140e",
              "status": "affected",
              "version": "583be982d93479ea3d85091b0fd0b01201ede87d",
              "versionType": "git"
            },
            {
              "lessThan": "288ef37e0c463192dbb6436e61cdc07ce666dcb9",
              "status": "affected",
              "version": "583be982d93479ea3d85091b0fd0b01201ede87d",
              "versionType": "git"
            },
            {
              "lessThan": "af6e4f931afc2d670d133aa2bedc8b6e3753c618",
              "status": "affected",
              "version": "583be982d93479ea3d85091b0fd0b01201ede87d",
              "versionType": "git"
            },
            {
              "lessThan": "63120572edde85bb2b70b0ed4d4817ed52247613",
              "status": "affected",
              "version": "583be982d93479ea3d85091b0fd0b01201ede87d",
              "versionType": "git"
            },
            {
              "lessThan": "f37f42e6e039a48c2dcf6c079b9f7fbc864ab7ef",
              "status": "affected",
              "version": "583be982d93479ea3d85091b0fd0b01201ede87d",
              "versionType": "git"
            },
            {
              "lessThan": "aadf655e8ea9a8ffa24bb8d69f504572e8d18181",
              "status": "affected",
              "version": "583be982d93479ea3d85091b0fd0b01201ede87d",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/mctp/device.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
            {
              "lessThan": "5.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.224",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.191",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.56",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mctp: publish the mctp_dev only after it is initialised\n\nmctp_add_dev() links the new mctp_dev into dev-\u003emctp_ptr before mdev-\u003edev\nis assigned, so a reader that picks the device up in that window\ndereferences a net_device pointer that is still NULL:\n\nKASAN: null-ptr-deref in range [0x00000000000000b0-0x00000000000000b7]\nCall Trace:\n \u003cTASK\u003e\n ? __pfx_mctp_sendmsg (./include/linux/sockptr.h:49)\n ? __pfx_mctp_dst_output (net/mctp/route.c:41)\n ? selinux_socket_sendmsg (security/selinux/hooks.c:5278)\n ____sys_sendmsg (net/socket.c:775 (discriminator 1) net/socket.c:790\n (discriminator 1) net/socket.c:2684 (discriminator 1))\n ? __pfx_____sys_sendmsg (net/socket.c:1131)\n ? __pfx_copy_msghdr_from_user (net/socket.c:2590)\n ? update_cfs_rq_load_avg (kernel/sched/fair.c:5478)\n ___sys_sendmsg (net/socket.c:2738)\n ? __pfx____sys_sendmsg (net/socket.c:2625)\n ? perf_event_task_tick (./include/linux/rcupdate.h:838)\n ? sched_tick (kernel/sched/core.c:5818)\n ? clockevents_program_event (kernel/time/clockevents.c:372)\n ? fdget (./include/linux/rcupdate.h:873 fs/file.c:1100)\n __sys_sendmsg (net/socket.c:2770)\n ? __pfx___sys_sendmsg (net/socket.c:2751)\n do_syscall_64 (arch/x86/entry/syscall_64.c:63)\n entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n \u003c/TASK\u003e\n\nFix by publishing only once the object is fully initialised:\n__mctp_dev_get() runs under rcu_read_lock() only and hands\nthis object to readers as soon as mctp_ptr is assigned, so\nthey must never observe mdev-\u003edev == NULL."
    }
  ],
  "id": "CVE-2026-98812",
  "lastModified": "2026-10-30T13:21:28.907",
  "metrics": {},
  "published": "2026-10-18T16:17:35.313",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/288ef37e0c463192dbb6436e61cdc07ce666dcb9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/58a270b5ecd8629114a4754d642bad6a33bef493"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/63120572edde85bb2b70b0ed4d4817ed52247613"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/aadf655e8ea9a8ffa24bb8d69f504572e8d18181"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/af6e4f931afc2d670d133aa2bedc8b6e3753c618"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f37f42e6e039a48c2dcf6c079b9f7fbc864ab7ef"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fdf09d0fa2fb639950bede185d22689f68df140e"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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