CVE-2026-31426 (GCVE-0-2026-31426)
Vulnerability from cvelistv5
Published
2026-04-13 13:40
Modified
2026-04-13 13:40
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()
When ec_install_handlers() returns -EPROBE_DEFER on reduced-hardware
platforms, it has already started the EC and installed the address
space handler with the struct acpi_ec pointer as handler context.
However, acpi_ec_setup() propagates the error without any cleanup.
The caller acpi_ec_add() then frees the struct acpi_ec for non-boot
instances, leaving a dangling handler context in ACPICA.
Any subsequent AML evaluation that accesses an EC OpRegion field
dispatches into acpi_ec_space_handler() with the freed pointer,
causing a use-after-free:
BUG: KASAN: slab-use-after-free in mutex_lock (kernel/locking/mutex.c:289)
Write of size 8 at addr ffff88800721de38 by task init/1
Call Trace:
<TASK>
mutex_lock (kernel/locking/mutex.c:289)
acpi_ec_space_handler (drivers/acpi/ec.c:1362)
acpi_ev_address_space_dispatch (drivers/acpi/acpica/evregion.c:293)
acpi_ex_access_region (drivers/acpi/acpica/exfldio.c:246)
acpi_ex_field_datum_io (drivers/acpi/acpica/exfldio.c:509)
acpi_ex_extract_from_field (drivers/acpi/acpica/exfldio.c:700)
acpi_ex_read_data_from_field (drivers/acpi/acpica/exfield.c:327)
acpi_ex_resolve_node_to_value (drivers/acpi/acpica/exresolv.c:392)
</TASK>
Allocated by task 1:
acpi_ec_alloc (drivers/acpi/ec.c:1424)
acpi_ec_add (drivers/acpi/ec.c:1692)
Freed by task 1:
kfree (mm/slub.c:6876)
acpi_ec_add (drivers/acpi/ec.c:1751)
The bug triggers on reduced-hardware EC platforms (ec->gpe < 0)
when the GPIO IRQ provider defers probing. Once the stale handler
exists, any unprivileged sysfs read that causes AML to touch an
EC OpRegion (battery, thermal, backlight) exercises the dangling
pointer.
Fix this by calling ec_remove_handlers() in the error path of
acpi_ec_setup() before clearing first_ec. ec_remove_handlers()
checks each EC_FLAGS_* bit before acting, so it is safe to call
regardless of how far ec_install_handlers() progressed:
-ENODEV (handler not installed): only calls acpi_ec_stop()
-EPROBE_DEFER (handler installed): removes handler, stops EC
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 03e9a0e05739cf872fee494b06c75c0469704a21 Version: 03e9a0e05739cf872fee494b06c75c0469704a21 Version: 03e9a0e05739cf872fee494b06c75c0469704a21 Version: 03e9a0e05739cf872fee494b06c75c0469704a21 Version: 03e9a0e05739cf872fee494b06c75c0469704a21 Version: 03e9a0e05739cf872fee494b06c75c0469704a21 |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/acpi/ec.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
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},
{
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},
{
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"versionType": "git"
},
{
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},
{
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{
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}
]
},
{
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"product": "Linux",
"programFiles": [
"drivers/acpi/ec.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.7"
},
{
"lessThan": "5.7",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.168",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.131",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.80",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.21",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.19.*",
"status": "unaffected",
"version": "6.19.11",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.168",
"versionStartIncluding": "5.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.131",
"versionStartIncluding": "5.7",
"vulnerable": true
},
{
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},
{
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"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.19.11",
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"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.0",
"versionStartIncluding": "5.7",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nACPI: EC: clean up handlers on probe failure in acpi_ec_setup()\n\nWhen ec_install_handlers() returns -EPROBE_DEFER on reduced-hardware\nplatforms, it has already started the EC and installed the address\nspace handler with the struct acpi_ec pointer as handler context.\nHowever, acpi_ec_setup() propagates the error without any cleanup.\n\nThe caller acpi_ec_add() then frees the struct acpi_ec for non-boot\ninstances, leaving a dangling handler context in ACPICA.\n\nAny subsequent AML evaluation that accesses an EC OpRegion field\ndispatches into acpi_ec_space_handler() with the freed pointer,\ncausing a use-after-free:\n\n BUG: KASAN: slab-use-after-free in mutex_lock (kernel/locking/mutex.c:289)\n Write of size 8 at addr ffff88800721de38 by task init/1\n Call Trace:\n \u003cTASK\u003e\n mutex_lock (kernel/locking/mutex.c:289)\n acpi_ec_space_handler (drivers/acpi/ec.c:1362)\n acpi_ev_address_space_dispatch (drivers/acpi/acpica/evregion.c:293)\n acpi_ex_access_region (drivers/acpi/acpica/exfldio.c:246)\n acpi_ex_field_datum_io (drivers/acpi/acpica/exfldio.c:509)\n acpi_ex_extract_from_field (drivers/acpi/acpica/exfldio.c:700)\n acpi_ex_read_data_from_field (drivers/acpi/acpica/exfield.c:327)\n acpi_ex_resolve_node_to_value (drivers/acpi/acpica/exresolv.c:392)\n \u003c/TASK\u003e\n\n Allocated by task 1:\n acpi_ec_alloc (drivers/acpi/ec.c:1424)\n acpi_ec_add (drivers/acpi/ec.c:1692)\n\n Freed by task 1:\n kfree (mm/slub.c:6876)\n acpi_ec_add (drivers/acpi/ec.c:1751)\n\nThe bug triggers on reduced-hardware EC platforms (ec-\u003egpe \u003c 0)\nwhen the GPIO IRQ provider defers probing. Once the stale handler\nexists, any unprivileged sysfs read that causes AML to touch an\nEC OpRegion (battery, thermal, backlight) exercises the dangling\npointer.\n\nFix this by calling ec_remove_handlers() in the error path of\nacpi_ec_setup() before clearing first_ec. ec_remove_handlers()\nchecks each EC_FLAGS_* bit before acting, so it is safe to call\nregardless of how far ec_install_handlers() progressed:\n\n -ENODEV (handler not installed): only calls acpi_ec_stop()\n -EPROBE_DEFER (handler installed): removes handler, stops EC"
}
],
"providerMetadata": {
"dateUpdated": "2026-04-13T13:40:29.635Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/022d1727f33ff90b3e1775125264e3023901952e"
},
{
"url": "https://git.kernel.org/stable/c/9c886e63b69658959633937e3acb7ca8addf7499"
},
{
"url": "https://git.kernel.org/stable/c/808c0f156f48d5b8ca34088cbbfba8444e606cbc"
},
{
"url": "https://git.kernel.org/stable/c/d04c007047c88158141d9bd5eac761cdadd3782c"
},
{
"url": "https://git.kernel.org/stable/c/be1a827e15991e874e0d5222d0ea5fdad01960fe"
},
{
"url": "https://git.kernel.org/stable/c/f6484cadbcaf26b5844b51bd7307a663dda48ef6"
}
],
"title": "ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-31426",
"datePublished": "2026-04-13T13:40:29.635Z",
"dateReserved": "2026-03-09T15:48:24.088Z",
"dateUpdated": "2026-04-13T13:40:29.635Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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