CVE-2026-98166

HIGH 7.8

Published 2026-10-06 · Last modified 2026-10-19

In the Linux kernel, the following vulnerability has been resolved: drm/ttm: fix swapped-out resources never leaving their bulk_move range ttm_tt_swapout() returns the number of pages swapped out on success and a negative error code on failure; for a populated ttm it never returns zero. Commit b2ed01e7ad3d ("drm/ttm: Fix ttm_bo_swapout() infinite LRU walk on swapout failure") moved the bulk_move bookkeeping in ttm_bo_swapout_cb() under "if (!ret)", so the ttm_resource_del_bulk_move_unevictable() / ttm_resource_move_to_lru_tail() pair is now skipped on every successful swapout. The equivalent change for the shrinker in commit 1d59f36e95f7 ("drm/ttm: Fix ttm_bo_shrink() infinite LRU walk on backup failure") tests "lret > 0", which is what was intended here as well. Before b2ed01e7ad3d the resource was taken off the bulk_move before the swapout; since then a swapped-out resource stays inside its BO's bulk_move range (and on the manager LRU) although it is unevictable. When it is later freed or the BO leaves the bulk_move (ttm_resource_free(), ttm_bo_set_bulk_move() via amdgpu_vm_bo_del()), ttm_resource_del_bulk_move() skips it because of its !ttm_resource_unevictable() guard, so a range endpoint in pos->first / pos->last is left pointing at freed memory. The next ttm_lru_bulk_move_tail() or ttm_resource_add_bulk_move() on that cursor is a use-after-free, seen as the resv WARN in ttm_lru_bulk_move_add(), "list_del corruption" in ttm_resource_move_to_lru_tail() or a NULL dereference in ttm_resource_manager_next() -- minutes to hours after a hibernation, or at process exit / reboot following one. Samuel Ainsworth's analysis of drm/amd issue 5387 (see Link) identified the dangling cursor; the missing removal at swapout time is the reason it dangles. Testing the condition for success restores the removal. On an AMD Phoenix APU (ASUS UM3406GA, gfx1103) running suspend-then-hibernate on a 7.0.y stable kernel carrying the backport (Ubuntu 7.0.0-31) the bug crashed 5 of 18 hibernation cycles; a function profile of one hibernation showed 336 ttm_tt_swapout() calls and zero ttm_resource_del_bulk_move_unevictable() calls. With this change the removal happens for every swapped-out resource and 12 further cycles were clean.

ELEVATED IMPACT

Severe if exploited (CVSS 7.8), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.2%chance of exploitation in 30 days · 4th percentile

○ In CISA KEV ○ Catalogued PoC

Impact if exploited

7.8CVSS 3.1 · HIGH

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

What an attacker needs

⚠Access: Requires local access to the host
⚠Privileges: Requires a low-privilege account
✓User interaction: No user interaction needed
✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

No public PoC is currently catalogued.

Search for new PoCs

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Tracked sources are checked daily for recent CVEs, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Data snapshot: 2026-10-26T13:52:32.101Z

Affected

Vendors Linux

Products Linux

Weakness (CWE)

Not classified.

CVSS vector

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

References and research data (JSON)

Vendor product assessments

Showing 32 of 277 vendor product statements; 245 omitted. Read the full vendor advisory.

kernel as a component of Red Hat Enterprise Linux 10 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-64k-debug-modules-extra as a component of Red Hat Enterprise Linux 10 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-64k-debug-modules-extra
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-debug-core as a component of Red Hat Enterprise Linux 10 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-debug-core
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-doc as a component of Red Hat Enterprise Linux 10 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-doc
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-rt-64k-debug as a component of Red Hat Enterprise Linux 10 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-rt-64k-debug
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-rt-64k-modules-extra as a component of Red Hat Enterprise Linux 10 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-rt-64k-modules-extra
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-rt-debug-modules-extra as a component of Red Hat Enterprise Linux 10 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-rt-debug-modules-extra
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-uki-virt as a component of Red Hat Enterprise Linux 10 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-uki-virt
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel.src as a component of Red Hat Enterprise Linux 10 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel?arch=src
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-debug as a component of Red Hat Enterprise Linux 6 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-debug
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
perf as a component of Red Hat Enterprise Linux 6 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/perf
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-doc as a component of Red Hat Enterprise Linux 7 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-doc
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-rt-doc as a component of Red Hat Enterprise Linux 7 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-rt-doc
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel.src as a component of Red Hat Enterprise Linux 7 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel?arch=src
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-debug as a component of Red Hat Enterprise Linux 8 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-debug
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-ipaclones-internal as a component of Red Hat Enterprise Linux 8 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-ipaclones-internal
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-rt-debug-devel as a component of Red Hat Enterprise Linux 8 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-rt-debug-devel
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-rt-modules-internal as a component of Red Hat Enterprise Linux 8 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-rt-modules-internal
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-zfcpdump-devel as a component of Red Hat Enterprise Linux 8 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-zfcpdump-devel
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-64k as a component of Red Hat Enterprise Linux 9 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-64k
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-64k-debug-modules-internal as a component of Red Hat Enterprise Linux 9 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-64k-debug-modules-internal
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-abi-stablelists as a component of Red Hat Enterprise Linux 9 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-abi-stablelists
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-debug-modules-extra as a component of Red Hat Enterprise Linux 9 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-debug-modules-extra
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-ipaclones-internal as a component of Red Hat Enterprise Linux 9 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-ipaclones-internal
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-rt-64k-debug as a component of Red Hat Enterprise Linux 9 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-rt-64k-debug
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-rt-64k-debug-modules-partner as a component of Red Hat Enterprise Linux 9 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-rt-64k-debug-modules-partner
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-rt-64k-modules-partner as a component of Red Hat Enterprise Linux 9 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-rt-64k-modules-partner
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-rt-debug-modules-extra as a component of Red Hat Enterprise Linux 9 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-rt-debug-modules-extra
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-rt-modules-internal as a component of Red Hat Enterprise Linux 9 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-rt-modules-internal
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-uki-virt-addons as a component of Red Hat Enterprise Linux 9 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-uki-virt-addons
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
kernel-zfcpdump-modules-partner as a component of Red Hat Enterprise Linux 9 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:rpm/redhat/kernel-zfcpdump-modules-partner
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4 · known not affected

Vendor assessment for this product only.
Reason: vulnerable code not present

pkg:oci/ose-rhel-coreos-9?repository_url=registry.redhat.io/openshift/ose-rhel-coreos-9
Red Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00

All CVSS metrics

HIGH 7.8 v3.1 · CNA Primary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
HIGH 7.8 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Advisories

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98166.json vendor-advisoryRed Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-93094 ADVISORYEUVD · EUVD-2026-93094

Technical & other

https://git.kernel.org/stable/c/1169fe8c11ca45e3f91d59a73eb271d0ca8a7fb0CVE record · Linux · Updated 2026-10-19T09:14:57.782Z
NVD · CVE-2026-98166 · Updated 2026-10-19T10:18:16.820
https://git.kernel.org/stable/c/3db7d7d583419f7b1f2e141e36418802dbb25cf8CVE record · Linux · Updated 2026-10-19T09:14:57.782Z
NVD · CVE-2026-98166 · Updated 2026-10-19T10:18:16.820
https://access.redhat.com/security/cve/CVE-2026-98166 vendor-referenceRed Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
https://bugzilla.redhat.com/show_bug.cgi?id=2546426 vendor-referenceRed Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
https://www.cve.org/CVERecord?id=CVE-2026-98166 vendor-referenceRed Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
https://nvd.nist.gov/vuln/detail/CVE-2026-98166 vendor-referenceRed Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98166.mbox vendor-referenceRed Hat · CVE-2026-98166 · Updated 2026-10-07T07:18:55+00:00

Sources: NVD · CVE.org · EPSS