CVE-2026-98812 (GCVE-0-2026-98812)

Vulnerability from cvelistv5 – Published: 2026-10-18 15:48 – Updated: 2026-10-21 12:57
VLAI
Title
net/mctp: publish the mctp_dev only after it is initialised
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.
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 7033 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 583be982d93479ea3d85091b0fd0b01201ede87d , < 288ef37e0c463192dbb6436e61cdc07ce666dcb9 (git)
Affected: 583be982d93479ea3d85091b0fd0b01201ede87d , < af6e4f931afc2d670d133aa2bedc8b6e3753c618 (git)
Affected: 583be982d93479ea3d85091b0fd0b01201ede87d , < 63120572edde85bb2b70b0ed4d4817ed52247613 (git)
Affected: 583be982d93479ea3d85091b0fd0b01201ede87d , < f37f42e6e039a48c2dcf6c079b9f7fbc864ab7ef (git)
Affected: 583be982d93479ea3d85091b0fd0b01201ede87d , < aadf655e8ea9a8ffa24bb8d69f504572e8d18181 (git)
guessed Create a notification for this product.
Linux Linux Affected: 5.15
Unaffected: 0 , < 5.15 (semver)
Unaffected: 6.6.160 , ≤ 6.6.* (semver)
Unaffected: 6.12.113 , ≤ 6.12.* (semver)
Unaffected: 6.18.56 , ≤ 6.18.* (semver)
Unaffected: 7.2.10 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
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        {
          "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."
        }
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      "providerMetadata": {
        "dateUpdated": "2026-10-21T12:57:11.501Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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          "url": "https://git.kernel.org/stable/c/288ef37e0c463192dbb6436e61cdc07ce666dcb9"
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          "url": "https://git.kernel.org/stable/c/af6e4f931afc2d670d133aa2bedc8b6e3753c618"
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    "datePublished": "2026-10-18T15:48:58.470Z",
    "dateReserved": "2026-09-25T10:25:14.371Z",
    "dateUpdated": "2026-10-21T12:57:11.501Z",
    "state": "PUBLISHED"
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      "date": "2026-10-29",
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      "percentile": "0.07015"
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      "cve": "CVE-2026-98812",
      "id": "msrc_CVE-2026-98812",
      "initial_release_date": "2026-10-20T01:06:28.000Z",
      "product_status:known_not_affected": "1",
      "product_status:under_investigation": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "net/mctp: publish the mctp_dev only after it is initialised",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-98812.json",
      "version": "4"
    },
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                "product": "Linux",
                "programFiles": [
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                    "status": "unaffected",
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        "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": "2026-10-21T13:21:47.813",
        "metrics": {},
        "published": "2026-10-18T16:17:35.313",
        "references": [
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            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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        "vulnStatus": "Received"
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    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-10-23T19:20:38+00:00",
      "cve": "CVE-2026-98812",
      "id": "CVE-2026-98812",
      "initial_release_date": "2026-10-18T00:00:00+00:00",
      "product_status:known_not_affected": "278",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: net/mctp: publish the mctp_dev only after it is initialised",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98812.json",
      "version": "3"
    },
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      "aggregate_severity": "moderate",
      "current_release_date": "2026-10-19T23:47:21Z",
      "cve": "CVE-2026-98812",
      "id": "CVE-2026-98812",
      "initial_release_date": "2026-10-18T23:41:55Z",
      "product_status:known_affected": "62",
      "product_status:known_not_affected": "286",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-98812",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/2026/cve-2026-98812.json",
      "version": "3"
    }
  }
}



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