Vulnerability-Lookup

UBUNTU-CVE-2026-98815 (CVE-2026-98815)

Vulnerability from osv_ubuntu – Published: 2026-10-18 16:17 – Updated: 2026-10-30 19:02 – Source website

Details

In the Linux kernel, the following vulnerability has been resolved: nvme: fix cdev lifetime Sashiko bot reported a potential problem for the cdev lifetime in [0] - the code there is heavily based on the NVMe code. Currently the NS head .open and .release file_operations methods take and put a reference to the nvme_ns_head to ensure that this structure does not disappear while we open fds for that cdev. In multipath mode, when we teardown the NS head, we call nvme_cdev_del() -> cdev_device_del() -> cdev_del(). However after cdev_del() returns, cdevs already open will remain and their fops will still be callable. As such, we can still reference the cdev after the nvme_ns_head reference count drops to 0 (and is freed). This can be shown with an application which delays between opening the cdev and issuing the ioctl while the NS head is being torn down: # ./ioctl_file /dev/ng1n1 & # waiting 10 seconds .... # ./ini_nvme_teardown.sh [ 21.221718] nvme nvme1: Removing ctrl: NQN "nvme-test-target" [ 21.274609] nvme nvme2: Removing ctrl: NQN "nvme-test-target" # now going to issue ioctl .... [ 26.549285] ================================================================== [ 26.550841] BUG: KASAN: slab-use-after-free in cdev_put.part.0+0x3d/0x40 [ 26.552352] Read of size 8 at addr ffff88811e7fa170 by task ioctl_file/237 [ 26.553805] [ 26.554227] CPU: 3 UID: 0 PID: 237 Comm: ioctl_file Not tainted 7.2.0-rc1-00004-g6852a10e32d4 #921 PREEMPT(lazy) [ 26.554236] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 26.554241] Call Trace: [ 26.554245] [ 26.554248] dump_stack_lvl+0x68/0xa0 [ 26.554266] print_report+0x10d/0x5d0 [ 26.554276] ? __virt_addr_valid+0x21d/0x3f0 [ 26.554287] ? cdev_put.part.0+0x3d/0x40 [ 26.554292] kasan_report+0x96/0xd0 [ 26.554300] ? cdev_put.part.0+0x3d/0x40 [ 26.554307] cdev_put.part.0+0x3d/0x40 [ 26.554313] __fput+0x7bc/0xa70 [ 26.554322] fput_close_sync+0xd8/0x190 [ 26.554328] ? __pfx_fput_close_sync+0x10/0x10 [ 26.554337] __x64_sys_close+0x79/0xd0 [ 26.554344] do_syscall_64+0x117/0x6b0 [ 26.554351] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 26.554358] RIP: 0033:0x7f938c067727 [ 26.554364] Code: 48 89 fa 4c 89 df e8 28 ad 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5bf [ 26.554369] RSP: 002b:00007fff49f05980 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 [ 26.554376] RAX: ffffffffffffffda RBX: 00007f938bfd7780 RCX: 00007f938c067727 [ 26.554380] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 [ 26.554383] RBP: 00007fff49f05a10 R08: 0000000000000000 R09: 0000000000000000 [ 26.554386] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 [ 26.554389] R13: 00007fff49f05b40 R14: 00007f938c207000 R15: 000055c148471d78 [ 26.554397] [ 26.554399] [ 26.575612] Allocated by task 100: [ 26.575871] kasan_save_stack+0x24/0x50 [ 26.576157] kasan_save_track+0x14/0x30 [ 26.576418] __kasan_kmalloc+0x7f/0x90 [ 26.576668] __kmalloc_noprof+0x281/0x6c0 [ 26.576938] nvme_alloc_ns+0x7f7/0x3170 [ 26.577206] nvme_scan_ns+0x508/0x880 [ 26.577449] async_run_entry_fn+0x8c/0x350 [ 26.577723] process_scheduled_works+0xb6f/0x1a00 [ 26.578034] worker_thread+0x4ad/0xb40 [ 26.578283] kthread+0x34f/0x450 [ 26.578501] ret_from_fork+0x563/0x800 [ 26.578752] ret_from_fork_asm+0x1a/0x30 [ 26.579012] [ 26.579124] Freed by task 237: [ 26.579335] kasan_save_stack+0x24/0x50 [ 26.579596] kasan_save_track+0x14/0x30 [ 26.579855] kasan_save_free_info+0x3a/0x60 [ 26.580131] __kasan_slab_free+0x43/0x70 [ 26.580388] kfree+0x321/0x500 [ 26.580591] nvme_ns_head_chr_release+0x39/0x50 [ 26.580883] __fput+0x352/0xa70 [ 26.581095] fput_close_sync+0xd8/0x190 [ 26.581350] __x64_sys_close+0x79/0xd0 [ 26.581595] do_syscall_64+0x117/0x6b0 [ 26.581842] entry_SYSCAL ---truncated---

Severity

N/A (UNKNOWN)

low

References

URL

Type

	https://ubuntu.com/security/CVE-2026-98815	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-98815	REPORT
	https://git.kernel.org/stable/c/98b09ad7934482e64…	REPORT
	https://git.kernel.org/stable/c/9952f3882ecba7090…	REPORT

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CVE-2026-98815 (GCVE-0-2026-98815)

Vulnerability from cvelistv5 – Published: 2026-10-18 15:49 – Updated: 2026-10-26 06:55

Title

nvme: fix cdev lifetime

Summary

In the Linux kernel, the following vulnerability has been resolved: nvme: fix cdev lifetime Sashiko bot reported a potential problem for the cdev lifetime in [0] - the code there is heavily based on the NVMe code. Currently the NS head .open and .release file_operations methods take and put a reference to the nvme_ns_head to ensure that this structure does not disappear while we open fds for that cdev. In multipath mode, when we teardown the NS head, we call nvme_cdev_del() -> cdev_device_del() -> cdev_del(). However after cdev_del() returns, cdevs already open will remain and their fops will still be callable. As such, we can still reference the cdev after the nvme_ns_head reference count drops to 0 (and is freed). This can be shown with an application which delays between opening the cdev and issuing the ioctl while the NS head is being torn down: # ./ioctl_file /dev/ng1n1 & # waiting 10 seconds .... # ./ini_nvme_teardown.sh [ 21.221718] nvme nvme1: Removing ctrl: NQN "nvme-test-target" [ 21.274609] nvme nvme2: Removing ctrl: NQN "nvme-test-target" # now going to issue ioctl .... [ 26.549285] ================================================================== [ 26.550841] BUG: KASAN: slab-use-after-free in cdev_put.part.0+0x3d/0x40 [ 26.552352] Read of size 8 at addr ffff88811e7fa170 by task ioctl_file/237 [ 26.553805] [ 26.554227] CPU: 3 UID: 0 PID: 237 Comm: ioctl_file Not tainted 7.2.0-rc1-00004-g6852a10e32d4 #921 PREEMPT(lazy) [ 26.554236] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 26.554241] Call Trace: [ 26.554245] <TASK> [ 26.554248] dump_stack_lvl+0x68/0xa0 [ 26.554266] print_report+0x10d/0x5d0 [ 26.554276] ? __virt_addr_valid+0x21d/0x3f0 [ 26.554287] ? cdev_put.part.0+0x3d/0x40 [ 26.554292] kasan_report+0x96/0xd0 [ 26.554300] ? cdev_put.part.0+0x3d/0x40 [ 26.554307] cdev_put.part.0+0x3d/0x40 [ 26.554313] __fput+0x7bc/0xa70 [ 26.554322] fput_close_sync+0xd8/0x190 [ 26.554328] ? __pfx_fput_close_sync+0x10/0x10 [ 26.554337] __x64_sys_close+0x79/0xd0 [ 26.554344] do_syscall_64+0x117/0x6b0 [ 26.554351] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 26.554358] RIP: 0033:0x7f938c067727 [ 26.554364] Code: 48 89 fa 4c 89 df e8 28 ad 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5bf [ 26.554369] RSP: 002b:00007fff49f05980 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 [ 26.554376] RAX: ffffffffffffffda RBX: 00007f938bfd7780 RCX: 00007f938c067727 [ 26.554380] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 [ 26.554383] RBP: 00007fff49f05a10 R08: 0000000000000000 R09: 0000000000000000 [ 26.554386] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 [ 26.554389] R13: 00007fff49f05b40 R14: 00007f938c207000 R15: 000055c148471d78 [ 26.554397] </TASK> [ 26.554399] [ 26.575612] Allocated by task 100: [ 26.575871] kasan_save_stack+0x24/0x50 [ 26.576157] kasan_save_track+0x14/0x30 [ 26.576418] __kasan_kmalloc+0x7f/0x90 [ 26.576668] __kmalloc_noprof+0x281/0x6c0 [ 26.576938] nvme_alloc_ns+0x7f7/0x3170 [ 26.577206] nvme_scan_ns+0x508/0x880 [ 26.577449] async_run_entry_fn+0x8c/0x350 [ 26.577723] process_scheduled_works+0xb6f/0x1a00 [ 26.578034] worker_thread+0x4ad/0xb40 [ 26.578283] kthread+0x34f/0x450 [ 26.578501] ret_from_fork+0x563/0x800 [ 26.578752] ret_from_fork_asm+0x1a/0x30 [ 26.579012] [ 26.579124] Freed by task 237: [ 26.579335] kasan_save_stack+0x24/0x50 [ 26.579596] kasan_save_track+0x14/0x30 [ 26.579855] kasan_save_free_info+0x3a/0x60 [ 26.580131] __kasan_slab_free+0x43/0x70 [ 26.580388] kfree+0x321/0x500 [ 26.580591] nvme_ns_head_chr_release+0x39/0x50 [ 26.580883] __fput+0x352/0xa70 [ 26.581095] fput_close_sync+0xd8/0x190 [ 26.581350] __x64_sys_close+0x79/0xd0 [ 26.581595] do_syscall_64+0x117/0x6b0 [ 26.581842] entry_SYSCAL ---truncated---

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6820 records in the last 180 days details

References

2 references

URL	Tags
https://git.kernel.org/stable/c/98b09ad7934482e64…
https://git.kernel.org/stable/c/9952f3882ecba7090…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 2637baed78010eeaae274feb5b99ce90933fadfb , < 98b09ad7934482e64db4b4477d91e3bbf43adf4c (git) Affected: 2637baed78010eeaae274feb5b99ce90933fadfb , < 9952f3882ecba709092379b71e02b09762b26f96 (git)
Linux	Linux	Affected: 5.13 Unaffected: 0 , < 5.13 (semver) Unaffected: 7.2.10 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/nvme/host/core.c",
            "drivers/nvme/host/multipath.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "98b09ad7934482e64db4b4477d91e3bbf43adf4c",
              "status": "affected",
              "version": "2637baed78010eeaae274feb5b99ce90933fadfb",
              "versionType": "git"
            },
            {
              "lessThan": "9952f3882ecba709092379b71e02b09762b26f96",
              "status": "affected",
              "version": "2637baed78010eeaae274feb5b99ce90933fadfb",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/nvme/host/core.c",
            "drivers/nvme/host/multipath.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.13"
            },
            {
              "lessThan": "5.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.10",
                  "versionStartIncluding": "5.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "5.13",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvme: fix cdev lifetime\n\nSashiko bot reported a potential problem for the cdev lifetime in [0]\n- the code there is heavily based on the NVMe code.\n\nCurrently the NS head .open and .release file_operations methods take and\nput a reference to the nvme_ns_head to ensure that this structure does not\ndisappear while we open fds for that cdev.\n\nIn multipath mode, when we teardown the NS head, we call nvme_cdev_del() -\u003e\ncdev_device_del() -\u003e cdev_del(). However after cdev_del() returns, cdevs\nalready open will remain and their fops will still be callable. As such,\nwe can still reference the cdev after the nvme_ns_head reference count\ndrops to 0 (and is freed).\n\nThis can be shown with an application which delays between opening the cdev\nand issuing the ioctl while the NS head is being torn down:\n\n# ./ioctl_file /dev/ng1n1 \u0026\n# waiting 10 seconds ....\n\n# ./ini_nvme_teardown.sh\n[   21.221718] nvme nvme1: Removing ctrl: NQN \"nvme-test-target\"\n[   21.274609] nvme nvme2: Removing ctrl: NQN \"nvme-test-target\"\n# now going to issue ioctl ....\n[   26.549285] ==================================================================\n[   26.550841] BUG: KASAN: slab-use-after-free in cdev_put.part.0+0x3d/0x40\n[   26.552352] Read of size 8 at addr ffff88811e7fa170 by task ioctl_file/237\n[   26.553805]\n[   26.554227] CPU: 3 UID: 0 PID: 237 Comm: ioctl_file Not tainted 7.2.0-rc1-00004-g6852a10e32d4 #921 PREEMPT(lazy)\n[   26.554236] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n[   26.554241] Call Trace:\n[   26.554245]  \u003cTASK\u003e\n[   26.554248]  dump_stack_lvl+0x68/0xa0\n[   26.554266]  print_report+0x10d/0x5d0\n[   26.554276]  ? __virt_addr_valid+0x21d/0x3f0\n[   26.554287]  ? cdev_put.part.0+0x3d/0x40\n[   26.554292]  kasan_report+0x96/0xd0\n[   26.554300]  ? cdev_put.part.0+0x3d/0x40\n[   26.554307]  cdev_put.part.0+0x3d/0x40\n[   26.554313]  __fput+0x7bc/0xa70\n[   26.554322]  fput_close_sync+0xd8/0x190\n[   26.554328]  ? __pfx_fput_close_sync+0x10/0x10\n[   26.554337]  __x64_sys_close+0x79/0xd0\n[   26.554344]  do_syscall_64+0x117/0x6b0\n[   26.554351]  entry_SYSCALL_64_after_hwframe+0x77/0x7f\n[   26.554358] RIP: 0033:0x7f938c067727\n[   26.554364] Code: 48 89 fa 4c 89 df e8 28 ad 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 \u003c5bf\n[   26.554369] RSP: 002b:00007fff49f05980 EFLAGS: 00000202 ORIG_RAX: 0000000000000003\n[   26.554376] RAX: ffffffffffffffda RBX: 00007f938bfd7780 RCX: 00007f938c067727\n[   26.554380] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003\n[   26.554383] RBP: 00007fff49f05a10 R08: 0000000000000000 R09: 0000000000000000\n[   26.554386] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000\n[   26.554389] R13: 00007fff49f05b40 R14: 00007f938c207000 R15: 000055c148471d78\n[   26.554397]  \u003c/TASK\u003e\n[   26.554399]\n[   26.575612] Allocated by task 100:\n[   26.575871]  kasan_save_stack+0x24/0x50\n[   26.576157]  kasan_save_track+0x14/0x30\n[   26.576418]  __kasan_kmalloc+0x7f/0x90\n[   26.576668]  __kmalloc_noprof+0x281/0x6c0\n[   26.576938]  nvme_alloc_ns+0x7f7/0x3170\n[   26.577206]  nvme_scan_ns+0x508/0x880\n[   26.577449]  async_run_entry_fn+0x8c/0x350\n[   26.577723]  process_scheduled_works+0xb6f/0x1a00\n[   26.578034]  worker_thread+0x4ad/0xb40\n[   26.578283]  kthread+0x34f/0x450\n[   26.578501]  ret_from_fork+0x563/0x800\n[   26.578752]  ret_from_fork_asm+0x1a/0x30\n[   26.579012]\n[   26.579124] Freed by task 237:\n[   26.579335]  kasan_save_stack+0x24/0x50\n[   26.579596]  kasan_save_track+0x14/0x30\n[   26.579855]  kasan_save_free_info+0x3a/0x60\n[   26.580131]  __kasan_slab_free+0x43/0x70\n[   26.580388]  kfree+0x321/0x500\n[   26.580591]  nvme_ns_head_chr_release+0x39/0x50\n[   26.580883]  __fput+0x352/0xa70\n[   26.581095]  fput_close_sync+0xd8/0x190\n[   26.581350]  __x64_sys_close+0x79/0xd0\n[   26.581595]  do_syscall_64+0x117/0x6b0\n[   26.581842]  entry_SYSCAL\n---truncated---"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-26T06:55:52.556Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/98b09ad7934482e64db4b4477d91e3bbf43adf4c"
        },
        {
          "url": "https://git.kernel.org/stable/c/9952f3882ecba709092379b71e02b09762b26f96"
        }
      ],
      "title": "nvme: fix cdev lifetime",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98815",
    "datePublished": "2026-10-18T15:49:03.248Z",
    "dateReserved": "2026-09-25T10:25:14.371Z",
    "dateUpdated": "2026-10-26T06:55:52.556Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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