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Response snapshot Oct 27, 2026, 02:21 UTC

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VulnerabilityCVE-2026-98515

Linux kernel: drm/nouveau: fix double-free in nvif_vmm_dtor

In the Linux kernel, the following vulnerability has been resolved: drm/nouveau: fix double-free in nvif_vmm_dtor On failure, nouveau_cli_init() calls nouveau_cli_fini() to tear the client down. Then, nouveau_drm_open() also enters into its cleanup path and calls nouveau_cli_fini() AGAIN.

At a glance

Exploited
Not known
Severity
7.8 High (CVSS 3.1)
Chance of exploitation
0.2% in the next 30 days
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-98515 (opens a new tab)

What happened

In the Linux kernel, the following vulnerability has been resolved:

drm/nouveau: fix double-free in nvif_vmm_dtor

On failure, nouveau_cli_init() calls nouveau_cli_fini() to tear the client down. Then, nouveau_drm_open() also enters into its cleanup path and calls nouveau_cli_fini() AGAIN. nouveau_cli_fini() calls nouveau_vmm_fini():

void nouveau_vmm_fini(struct nouveau_vmm *vmm) { nouveau_svmm_fini(&vmm->svmm); nvif_vmm_dtor(&vmm->vmm); vmm->cli = NULL; }

Continue reading

Inside nvif_vmm_dtor(), vmm->page is freed unconditionally:

void nvif_vmm_dtor(struct nvif_vmm *vmm) { kfree(vmm->page); nvif_object_dtor(&vmm->object); }

vmm->page is never cleared after being freed, so the second call of nvif_vmm_dtor() will cause a double-free.

Found by fuzzing the nouveau driver with a modified Syzkaller:

BUG: KASAN: double-free in nvif_vmm_dtor+0x31/0x50 drivers/gpu/drm/nouveau/nvif/vmm.c:194 Free of addr ffff888010fcdc30 by task syz.0.173/2567

CPU: 1 UID: 0 PID: 2567 Comm: syz.0.173 Not tainted 7.2.0 #24 PREEMPT(lazy) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x95/0xe0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcb/0x5a0 mm/kasan/report.

c:482 kasan_report_invalid_free+0xaa/0xd0 mm/kasan/report.c:557 check_slab_allocation+0xe4/0x110 mm/kasan/common.c:235 kasan_slab_pre_free include/linux/kasan.h:199 [inline] slab_free_hook mm/slub.c:2622 [inline] slab_free mm/slub.c:6377 [inline] kfree+0x192/0x590 mm/slub.c:6692 nvif_vmm_dtor+0x31/0x50 drivers/gpu/drm/nouveau/nvif/vmm.c:194 nouveau_vmm_fini+0x16/0x50 drivers/gpu/drm/nouveau/nouveau_vmm.

c:127 nouveau_cli_fini+0x10e/0x210 drivers/gpu/drm/nouveau/nouveau_drm.c:225 nouveau_drm_open+0x24e/0x740 drivers/gpu/drm/nouveau/nouveau_drm.c:1255 drm_file_alloc+0x5f2/0xad0 drivers/gpu/drm/drm_file.c:176 drm_open_helper+0x1d7/0x4a0 drivers/gpu/drm/drm_file.c:335 drm_open+0x190/0x3d0 drivers/gpu/drm/drm_file.c:388 drm_stub_open+0x1f2/0x460 drivers/gpu/drm/drm_drv.c:1211 chrdev_open+0x21c/0x660 fs/char_dev.

c:411 do_dentry_open+0x59d/0x12b0 fs/open.c:947 vfs_open+0x82/0x390 fs/open.c:1052 do_open fs/namei.c:4700 [inline] path_openat+0x2345/0x3420 fs/namei.c:4863 do_file_open+0x207/0x460 fs/namei.c:4892 do_sys_openat2+0xd1/0x1d0 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x144/0x200 fs/open.

c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x690 arch/x86/entry/syscall_64.

c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc6d687594d Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc6d5295008 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fc6d6b06180 RCX: 00007fc6d687594d RDX: 0000000000022501 RSI: 0000200000000000 RDI: ffffffffffffff9c RBP: 00007fc6d691c303 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc6d6b06218 R14: 00007fc6d6b06180 R15: 00007ffd9451d760 </TASK>

Allocated by task 2567 on cpu 1 at 163.593900s: kasan_save_stack+0x24/0x50 mm/kasan/common.c:57 kasan_save_track+0x17/0x60 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5334 [inline] __kmalloc_noprof+0x304/0x7c0 mm/slub.c:5359 _kmalloc_noprof include/linux/slab.

h:992 [inline] nvif_vmm_ctor+0x3c0/0x7e0 drivers/gpu/drm/nouveau/nvif/vmm.c:237 nouveau_vmm_init+0x40/0x90 drivers/gpu/drm/nouveau/nouveau_vmm.c:134 nouveau_cli_init+0x7b9/0 ---truncated---

Scores and how they were measured

CVSS base severity

7.8

Version 3.1As of

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.2%

Scored Percentile 6.3%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2026-98515 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-98515, scored 2026-10-26. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 24). Linux kernel: drm/nouveau: fix double-free in nvif_vmm_dtor (CVE-2026-98515). https://kevwire.com/record/CVE-2026-98515

MLA

"Linux kernel: drm/nouveau: fix double-free in nvif_vmm_dtor (CVE-2026-98515)." KEVWire, 24 Oct. 2026, kevwire.com/record/CVE-2026-98515.

Chicago

KEVWire. "Linux kernel: drm/nouveau: fix double-free in nvif_vmm_dtor (CVE-2026-98515)." Last modified October 24, 2026. https://kevwire.com/record/CVE-2026-98515.

Evidence summary (plain text)

Linux kernel: drm/nouveau: fix double-free in nvif_vmm_dtor (Oct 18, 2026).
In the Linux kernel, the following vulnerability has been resolved:

drm/nouveau: fix double-free in nvif_vmm_dtor

On failure, nouveau_cli_init() calls nouveau_cli_fini() to tear
the client down. Then, nouveau_drm_open() also enters into its
cleanup path and calls nouveau_cli_fini() AGAIN. nouveau_cli_fini()
calls nouveau_vmm_fini():

	void
	nouveau_vmm_fini(struct nouveau_vmm *vmm)
	{
		nouveau_svmm_fini(&vmm->svmm);
		nvif_vmm_dtor(&vmm->vmm);
		vmm->cli = NULL;
	}

Inside nvif_vmm_dtor(), vmm->page is freed unconditionally:

	void
	nvif_vmm_dtor(struct nvif_vmm *vmm)
	{
		kfree(vmm->page);
		nvif_object_dtor(&vmm->object);
	}

vmm->page is never cleared after being freed, so the second call of
nvif_vmm_dtor() will cause a double-free.

Found by fuzzing the nouveau driver with a modified Syzkaller:

	BUG: KASAN: double-free in nvif_vmm_dtor+0x31/0x50 drivers/gpu/drm/nouveau/nvif/vmm.c:194
	Free of addr ffff888010fcdc30 by task syz.0.173/2567

	CPU: 1 UID: 0 PID: 2567 Comm: syz.0.173 Not tainted 7.2.0 #24 PREEMPT(lazy)
	Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
	Call Trace:
	<TASK>
	__dump_stack lib/dump_stack.c:94 [inline]
	dump_stack_lvl+0x95/0xe0 lib/dump_stack.c:120
	print_address_description mm/kasan/report.c:378 [inline]
	print_report+0xcb/0x5a0 mm/kasan/report.c:482
	kasan_report_invalid_free+0xaa/0xd0 mm/kasan/report.c:557
	check_slab_allocation+0xe4/0x110 mm/kasan/common.c:235
	kasan_slab_pre_free include/linux/kasan.h:199 [inline]
	slab_free_hook mm/slub.c:2622 [inline]
	slab_free mm/slub.c:6377 [inline]
	kfree+0x192/0x590 mm/slub.c:6692
	nvif_vmm_dtor+0x31/0x50 drivers/gpu/drm/nouveau/nvif/vmm.c:194
	nouveau_vmm_fini+0x16/0x50 drivers/gpu/drm/nouveau/nouveau_vmm.c:127
	nouveau_cli_fini+0x10e/0x210 drivers/gpu/drm/nouveau/nouveau_drm.c:225
	nouveau_drm_open+0x24e/0x740 drivers/gpu/drm/nouveau/nouveau_drm.c:1255
	drm_file_alloc+0x5f2/0xad0 drivers/gpu/drm/drm_file.c:176
	drm_open_helper+0x1d7/0x4a0 drivers/gpu/drm/drm_file.c:335
	drm_open+0x190/0x3d0 drivers/gpu/drm/drm_file.c:388
	drm_stub_open+0x1f2/0x460 drivers/gpu/drm/drm_drv.c:1211
	chrdev_open+0x21c/0x660 fs/char_dev.c:411
	do_dentry_open+0x59d/0
CVSS 7.8 (version 3.1; evidence as of Oct 24, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-98515).
EPSS 0.2% for the following 30 days, scored Oct 26, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-98515&date=2026-10-26).
Sources:
NVD CVE-2026-98515: https://nvd.nist.gov/vuln/detail/CVE-2026-98515
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?pubStartDate=2026-10-12T13:35:55.142Z&pubEndDate=2026-10-26T13:35:55.142Z&resultsPerPage=500&startIndex=4500
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-98515&date=2026-10-26
Record ID: CVE-2026-98515.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 27, 2026, 01:40 UTC. Ingestion is not an independent editorial investigation.

NVD status: Received. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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