CVE-2026-43250 (GCVE-0-2026-43250)
Vulnerability from cvelistv5 – Published: 2026-05-06 11:28 – Updated: 2026-05-06 11:28
VLAI?
Title
usb: chipidea: udc: fix DMA and SG cleanup in _ep_nuke()
Summary
In the Linux kernel, the following vulnerability has been resolved:
usb: chipidea: udc: fix DMA and SG cleanup in _ep_nuke()
The ChipIdea UDC driver can encounter "not page aligned sg buffer"
errors when a USB device is reconnected after being disconnected
during an active transfer. This occurs because _ep_nuke() returns
requests to the gadget layer without properly unmapping DMA buffers
or cleaning up scatter-gather bounce buffers.
Root cause:
When a disconnect happens during a multi-segment DMA transfer, the
request's num_mapped_sgs field and sgt.sgl pointer remain set with
stale values. The request is returned to the gadget driver with status
-ESHUTDOWN but still has active DMA state. If the gadget driver reuses
this request on reconnect without reinitializing it, the stale DMA
state causes _hardware_enqueue() to skip DMA mapping (seeing non-zero
num_mapped_sgs) and attempt to use freed/invalid DMA addresses,
leading to alignment errors and potential memory corruption.
The normal completion path via _hardware_dequeue() properly calls
usb_gadget_unmap_request_by_dev() and sglist_do_debounce() before
returning the request. The _ep_nuke() path must do the same cleanup
to ensure requests are returned in a clean, reusable state.
Fix:
Add DMA unmapping and bounce buffer cleanup to _ep_nuke() to mirror
the cleanup sequence in _hardware_dequeue():
- Call usb_gadget_unmap_request_by_dev() if num_mapped_sgs is set
- Call sglist_do_debounce() with copy=false if bounce buffer exists
This ensures that when requests are returned due to endpoint shutdown,
they don't retain stale DMA mappings. The 'false' parameter to
sglist_do_debounce() prevents copying data back (appropriate for
shutdown path where transfer was aborted).
Severity ?
No CVSS data available.
Assigner
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Affected:
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 1b72b834511d17f4d069d512f78671f3f210a2f1
(git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < f4fbf2d4750d12ac8525d2efac1016fa0d84d4ec (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < e74c436f8568af1c60942469d0a2300b3ada3857 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < cea2a1257a3b5ea3e769a445b34af13e6aa5a123 (git) |
||
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"programFiles": [
"drivers/usb/chipidea/udc.c"
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"versionType": "git"
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"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
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"version": "6.12.75",
"versionType": "semver"
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{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.16",
"versionType": "semver"
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{
"lessThanOrEqual": "6.19.*",
"status": "unaffected",
"version": "6.19.6",
"versionType": "semver"
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{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix"
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"descriptions": [
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"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: chipidea: udc: fix DMA and SG cleanup in _ep_nuke()\n\nThe ChipIdea UDC driver can encounter \"not page aligned sg buffer\"\nerrors when a USB device is reconnected after being disconnected\nduring an active transfer. This occurs because _ep_nuke() returns\nrequests to the gadget layer without properly unmapping DMA buffers\nor cleaning up scatter-gather bounce buffers.\n\nRoot cause:\nWhen a disconnect happens during a multi-segment DMA transfer, the\nrequest\u0027s num_mapped_sgs field and sgt.sgl pointer remain set with\nstale values. The request is returned to the gadget driver with status\n-ESHUTDOWN but still has active DMA state. If the gadget driver reuses\nthis request on reconnect without reinitializing it, the stale DMA\nstate causes _hardware_enqueue() to skip DMA mapping (seeing non-zero\nnum_mapped_sgs) and attempt to use freed/invalid DMA addresses,\nleading to alignment errors and potential memory corruption.\n\nThe normal completion path via _hardware_dequeue() properly calls\nusb_gadget_unmap_request_by_dev() and sglist_do_debounce() before\nreturning the request. The _ep_nuke() path must do the same cleanup\nto ensure requests are returned in a clean, reusable state.\n\nFix:\nAdd DMA unmapping and bounce buffer cleanup to _ep_nuke() to mirror\nthe cleanup sequence in _hardware_dequeue():\n- Call usb_gadget_unmap_request_by_dev() if num_mapped_sgs is set\n- Call sglist_do_debounce() with copy=false if bounce buffer exists\n\nThis ensures that when requests are returned due to endpoint shutdown,\nthey don\u0027t retain stale DMA mappings. The \u0027false\u0027 parameter to\nsglist_do_debounce() prevents copying data back (appropriate for\nshutdown path where transfer was aborted)."
}
],
"providerMetadata": {
"dateUpdated": "2026-05-06T11:28:41.158Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/1b72b834511d17f4d069d512f78671f3f210a2f1"
},
{
"url": "https://git.kernel.org/stable/c/f4fbf2d4750d12ac8525d2efac1016fa0d84d4ec"
},
{
"url": "https://git.kernel.org/stable/c/e74c436f8568af1c60942469d0a2300b3ada3857"
},
{
"url": "https://git.kernel.org/stable/c/cea2a1257a3b5ea3e769a445b34af13e6aa5a123"
}
],
"title": "usb: chipidea: udc: fix DMA and SG cleanup in _ep_nuke()",
"x_generator": {
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"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-43250",
"datePublished": "2026-05-06T11:28:41.158Z",
"dateReserved": "2026-05-01T14:12:55.996Z",
"dateUpdated": "2026-05-06T11:28:41.158Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2026-43250\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-05-06T12:16:45.620\",\"lastModified\":\"2026-05-06T13:07:51.607\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nusb: chipidea: udc: fix DMA and SG cleanup in _ep_nuke()\\n\\nThe ChipIdea UDC driver can encounter \\\"not page aligned sg buffer\\\"\\nerrors when a USB device is reconnected after being disconnected\\nduring an active transfer. This occurs because _ep_nuke() returns\\nrequests to the gadget layer without properly unmapping DMA buffers\\nor cleaning up scatter-gather bounce buffers.\\n\\nRoot cause:\\nWhen a disconnect happens during a multi-segment DMA transfer, the\\nrequest\u0027s num_mapped_sgs field and sgt.sgl pointer remain set with\\nstale values. The request is returned to the gadget driver with status\\n-ESHUTDOWN but still has active DMA state. If the gadget driver reuses\\nthis request on reconnect without reinitializing it, the stale DMA\\nstate causes _hardware_enqueue() to skip DMA mapping (seeing non-zero\\nnum_mapped_sgs) and attempt to use freed/invalid DMA addresses,\\nleading to alignment errors and potential memory corruption.\\n\\nThe normal completion path via _hardware_dequeue() properly calls\\nusb_gadget_unmap_request_by_dev() and sglist_do_debounce() before\\nreturning the request. The _ep_nuke() path must do the same cleanup\\nto ensure requests are returned in a clean, reusable state.\\n\\nFix:\\nAdd DMA unmapping and bounce buffer cleanup to _ep_nuke() to mirror\\nthe cleanup sequence in _hardware_dequeue():\\n- Call usb_gadget_unmap_request_by_dev() if num_mapped_sgs is set\\n- Call sglist_do_debounce() with copy=false if bounce buffer exists\\n\\nThis ensures that when requests are returned due to endpoint shutdown,\\nthey don\u0027t retain stale DMA mappings. The \u0027false\u0027 parameter to\\nsglist_do_debounce() prevents copying data back (appropriate for\\nshutdown path where transfer was aborted).\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/1b72b834511d17f4d069d512f78671f3f210a2f1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/cea2a1257a3b5ea3e769a445b34af13e6aa5a123\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/e74c436f8568af1c60942469d0a2300b3ada3857\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f4fbf2d4750d12ac8525d2efac1016fa0d84d4ec\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
}
}
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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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