FKIE_CVE-2026-68239
Vulnerability from fkie_nvd - Published: 2026-08-10 13:20 - Updated: 2026-08-17 05:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
drm/ttm: Account for NULL and handle pages in ttm_pool_backup
Pages in ttm_pool_backup can be NULL or backup handles
(ttm_backup_page_ptr_is_handle()), neither of which can be passed to
set_pages_array_wb() or freed. Add a dedicated WB pass before the
dma/purge loop that walks allocations using the same i += num_pages
stride, skipping NULL and handle entries, and calls set_pages_array_wb()
once per contiguous run of real pages. Apply the same NULL/handle guard
to the dma/purge loop.
Fixes the following oops:
Oops: general protection fault, kernel NULL pointer dereference 0x0: 0000 [#1] SMP NOPTI
RIP: 0010:__cpa_process_fault+0xf8/0x770
RSP: 0018:ffffc90000a87718 EFLAGS: 00010287
RAX: 0000000000000000 RBX: ffffc90000a87868 RCX: 0000000000000000
RDX: 0000000000001000 RSI: 0005088000000000 RDI: ffffffff827c5f34
RBP: 0005088000000000 R08: ffffc90000a877cb R09: ffffc90000a877d0
R10: 0000000000000000 R11: 000000000000001b R12: 000ffffffffff000
R13: ffffc90000a87868 R14: ffffc90000a87868 R15: ffff88815b882ae0
FS: 0000000000000000(0000) GS:ffff8884ec840000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f930b844000 CR3: 000000000262e003 CR4: 0000000008f70ef0
PKRU: 55555554
Call Trace:
<TASK>
__change_page_attr_set_clr+0x989/0xe90
? __purge_vmap_area_lazy+0x6c/0x3a0
? _vm_unmap_aliases+0x250/0x2a0
set_pages_array_wb+0x7f/0x120
ttm_pool_backup+0x4c9/0x5b0 [ttm]
? dma_resv_wait_timeout+0x3b/0xf0
ttm_tt_backup+0x32/0x60 [ttm]
ttm_bo_shrink+0x66/0x110 [ttm]
xe_bo_shrink_purge+0x12b/0x1b0 [xe]
xe_bo_shrink+0xbb/0x270 [xe]
__xe_shrinker_walk+0xf7/0x160 [xe]
xe_shrinker_walk+0x9d/0xc0 [xe]
xe_shrinker_scan+0x11f/0x210 [xe]
do_shrink_slab+0x13b/0x270
shrink_slab+0xf1/0x400
shrink_node+0x352/0x8a0
balance_pgdat+0x32c/0x700
kswapd+0x205/0x2f0
? __pfx_autoremove_wake_function+0x10/0x10
? __pfx_kswapd+0x10/0x10
kthread+0xd1/0x110
? __pfx_kthread+0x10/0x10
ret_from_fork+0x1b1/0x200
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/gpu/drm/ttm/ttm_pool.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "22aa7fb4e7d0b3ab41d1240ed743167980912970",
"status": "affected",
"version": "b63d715b8090aed48bdef5930625946fa4c0d324",
"versionType": "git"
},
{
"lessThan": "9ddaabf38f7a45b329e34358b98d2968d8649d21",
"status": "affected",
"version": "b63d715b8090aed48bdef5930625946fa4c0d324",
"versionType": "git"
},
{
"lessThan": "5b7b3b6595ee77d01c7463757baed114786094dd",
"status": "affected",
"version": "b63d715b8090aed48bdef5930625946fa4c0d324",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/gpu/drm/ttm/ttm_pool.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.15"
},
{
"lessThan": "6.15",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.42",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/ttm: Account for NULL and handle pages in ttm_pool_backup\n\nPages in ttm_pool_backup can be NULL or backup handles\n(ttm_backup_page_ptr_is_handle()), neither of which can be passed to\nset_pages_array_wb() or freed. Add a dedicated WB pass before the\ndma/purge loop that walks allocations using the same i += num_pages\nstride, skipping NULL and handle entries, and calls set_pages_array_wb()\nonce per contiguous run of real pages. Apply the same NULL/handle guard\nto the dma/purge loop.\n\nFixes the following oops:\n\nOops: general protection fault, kernel NULL pointer dereference 0x0: 0000 [#1] SMP NOPTI\nRIP: 0010:__cpa_process_fault+0xf8/0x770\nRSP: 0018:ffffc90000a87718 EFLAGS: 00010287\nRAX: 0000000000000000 RBX: ffffc90000a87868 RCX: 0000000000000000\nRDX: 0000000000001000 RSI: 0005088000000000 RDI: ffffffff827c5f34\nRBP: 0005088000000000 R08: ffffc90000a877cb R09: ffffc90000a877d0\nR10: 0000000000000000 R11: 000000000000001b R12: 000ffffffffff000\nR13: ffffc90000a87868 R14: ffffc90000a87868 R15: ffff88815b882ae0\nFS: 0000000000000000(0000) GS:ffff8884ec840000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f930b844000 CR3: 000000000262e003 CR4: 0000000008f70ef0\nPKRU: 55555554\nCall Trace:\n \u003cTASK\u003e\n __change_page_attr_set_clr+0x989/0xe90\n ? __purge_vmap_area_lazy+0x6c/0x3a0\n ? _vm_unmap_aliases+0x250/0x2a0\n set_pages_array_wb+0x7f/0x120\n ttm_pool_backup+0x4c9/0x5b0 [ttm]\n ? dma_resv_wait_timeout+0x3b/0xf0\n ttm_tt_backup+0x32/0x60 [ttm]\n ttm_bo_shrink+0x66/0x110 [ttm]\n xe_bo_shrink_purge+0x12b/0x1b0 [xe]\n xe_bo_shrink+0xbb/0x270 [xe]\n __xe_shrinker_walk+0xf7/0x160 [xe]\n xe_shrinker_walk+0x9d/0xc0 [xe]\n xe_shrinker_scan+0x11f/0x210 [xe]\n do_shrink_slab+0x13b/0x270\n shrink_slab+0xf1/0x400\n shrink_node+0x352/0x8a0\n balance_pgdat+0x32c/0x700\n kswapd+0x205/0x2f0\n ? __pfx_autoremove_wake_function+0x10/0x10\n ? __pfx_kswapd+0x10/0x10\n kthread+0xd1/0x110\n ? __pfx_kthread+0x10/0x10\n ret_from_fork+0x1b1/0x200\n ? __pfx_kthread+0x10/0x10\n ret_from_fork_asm+0x1a/0x30\n \u003c/TASK\u003e"
}
],
"id": "CVE-2026-68239",
"lastModified": "2026-08-17T05:18:26.187",
"metrics": {},
"published": "2026-08-10T13:20:12.273",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/22aa7fb4e7d0b3ab41d1240ed743167980912970"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/5b7b3b6595ee77d01c7463757baed114786094dd"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/9ddaabf38f7a45b329e34358b98d2968d8649d21"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
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.
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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