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NVD / CVE Program· CNA Linux

CVE-2026-89815: drm/ttm: Drop tt->restore after successful restore

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.17% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 329ddc5d438f991f49e4fd24c704d1c7288d5e03, 941ac10529b3be5965a88d432a161ab459672ba8, a46ab76b6cf5478e2ac7b942a377c7a1827b436a.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 329ddc5d438f991f49e4fd24c704d1c7288d5e03, 941ac10529b3be5965a88d432a161ab459672ba8, a46ab76b6cf5478e2ac7b942a377c7a1827b436a or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: drm/ttm: Drop tt->restore after successful restore ttm_pool_restore_and_alloc() can successfully complete the restore process via ttm_pool_restore_commit(), but tt->restore is not dropped afterward. As a result, subsequent backup/restore flows observe what appears to be a completed restore, while in reality shmem handles are still installed in tt->pages, leading to the stack trace below. Fix this by freeing and dropping tt->restore in ttm_pool_restore_and_alloc() upon successful completion of the restore. 20545 [  309.784531] RIP: 0010:sg_alloc_append_table_from_pages+0x38c/0x490 20547 [  309.809570] RSP: 0018:ffffc9000623b838 EFLAGS: 00010206 20548 [  309.814827] RAX: 0000000000001000 RBX: ffff88816e42a160 RCX: 0000000000000000 20549 [  309.821986] RDX: 0000000000002000 RSI: 0000000000000003 RDI: 0000000000001000 20550 [  309.829147] RBP: ffff88816e42a168 R08: 0000000000000002 R09: 000000007ffff000 20551 [  309.836310] R10: ffffc9000623b928 R11: 0000000000000000 R12: 000000007ffff000 20552 [  309.843471] R13: ffff88815ba5a100 R14: 0000000000000000 R15: 0000000000000001 20553 [  309.850634] FS:  00007f9ff305e700(0000) GS:ffff888276c94000(0000) knlGS:0000000000000000 20554 [  309.858749] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 20555 [  309.864519] CR2: 00007f9fca701000 CR3: 00000001565e2005 CR4: 0000000008f70ef0 20556 [  309.871678] PKRU: 55555558 20557 [  309.874403] Call Trace: 20558 [  309.876866]  <TASK> 20559 [  309.878988]  sg_alloc_table_from_pages_segment+0x60/0x100 20560 [  309.884415]  ? ttm_resource_manager_usage+0x36/0x60 [ttm] 20561 [  309.889845]  ? xe_tt_map_sg+0x7d/0xd0 [xe] 20562 [  309.894045]  xe_tt_map_sg+0x7d/0xd0 [xe] 20563 [  309.898037]  xe_bo_move+0x927/0xaa0 [xe] 20564 [  309.902029]  ttm_bo_handle_move_mem+0xba/0x170 [ttm] 20565 [  309.907022]  ttm_bo_validate+0xbe/0x190 [ttm] 20566 [  309.911405]  xe_bo_validate+0x9a/0x120 [xe] 20567 [  309.915663]  xe_gpuvm_validate+0xd9/0x140 [xe] 20568 [  309.920206]  drm_gpuvm_validate+0x2f0/0x5b0 [drm_gpuvm] 20569 [  309.925459]  ? drm_exec_lock_obj+0x63/0x210 [drm_exec] 20570 [  309.930627]  xe_vm_validate_rebind+0x46/0xb0 [xe] 20571 [  309.935428]  xe_exec_fn+0x20/0x40 [xe] 20572 [  309.939249]  drm_gpuvm_exec_lock+0x78/0xc0 [drm_gpuvm] 20573 [  309.944410]  xe_validation_exec_lock+0x5a/0xa0 [xe] 20574 [  309.949385]  xe_exec_ioctl+0x806/0xc30 [xe] 20575 [  309.953639]  ? ttwu_queue_wakelist+0xd9/0xf0 20576 [  309.957935]  ? __pfx_xe_exec_fn+0x10/0x10 [xe] 20577 [  309.962449]  ? __wake_up_common+0x73/0xa0 20578 [  309.966482]  ? __pfx_xe_exec_ioctl+0x10/0x10 [xe] 20579 [  309.971263]  drm_ioctl_kernel+0xa3/0x100 20580 [  309.975209]  drm_ioctl+0x213/0x440 20581 [  309.978637]  ? __pfx_xe_exec_ioctl+0x10/0x10 [xe] 20582 [  309.983415]  xe_drm_ioctl+0x67/0xd0 [xe] 20583 [  309.987408]  __x64_sys_ioctl+0x7f/0xd0

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Sep 16, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 6th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.15affected
    • b63d715b8090aed48bdef5930625946fa4c0d324 and later · before 329ddc5d438f991f49e4fd24c704d1c7288d5e03affected · git
    • b63d715b8090aed48bdef5930625946fa4c0d324 and later · before a46ab76b6cf5478e2ac7b942a377c7a1827b436aaffected · git
    • b63d715b8090aed48bdef5930625946fa4c0d324 and later · before 941ac10529b3be5965a88d432a161ab459672ba8affected · git
    • before 6.15not affected · semver
    • 6.18.53 and later · up to and including 6.18.*not affected · semver
    • 7.2.5 and later · up to and including 7.2.*not affected · semver
    • 7.3 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:14linuxbefore 7.2.6-17.2.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-89813Sep 16, 2026 · drm/amdgpu: force complete the KIQ ring fences on reset
    0Monitor
  • ← EarlierCVE-2026-89814Sep 16, 2026 · drm/amdgpu: clamp the isolation index for rings outside a partition
    31Monitor
  • Later →CVE-2026-89816Sep 16, 2026 · drm: Fix drm_crtc_commit leak if signaled when PAGE_FLIP_EVENT is used
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux329ddc5d438f991f49e4fd24c704d1c7288d5e03Vendor (CNA)
Linux Linux941ac10529b3be5965a88d432a161ab459672ba8Vendor (CNA)
Linux Linuxa46ab76b6cf5478e2ac7b942a377c7a1827b436aVendor (CNA)
debian:linux7.2.6-1 · Debian:14Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records