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CVE-2026-31426

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.0 · Élevée
EPSS 0.2%
Linux•Linux•Versions : <=6.1.*, <=6.12.*, <9c886e63b69658959633937e3acb7ca8addf7499, 0, <808c0f156f48d5b8ca34088cbbfba8444e606cbc, 7.0, <be1a827e15991e874e0d5222d0ea5fdad01960fe, <5.7, <=6.6.*, 6.19.11, <=6.19.*, <022d1727f33ff90b3e1775125264e3023901952e, <d04c007047c88158141d9bd5eac761cdadd3782c, <=6.18.*, 6.6.131, 6.12.80, <f6484cadbcaf26b5844b51bd7307a663dda48ef6, 5.7, <=*, 6.1.168, 6.18.21, 03e9a0e05739cf872fee494b06c75c0469704a21

Description

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

Gravité et risque d'exploitation

CVE-2026-31426 obtient un score CVSS de 7.0/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.15 %, ce qui la place devant 3.9 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, <=6.12.*, <9c886e63b69658959633937e3acb7ca8addf7499, 0, <808c0f156f48d5b8ca34088cbbfba8444e606cbc, 7.0, <be1a827e15991e874e0d5222d0ea5fdad01960fe, <5.7, <=6.6.*, 6.19.11, <=6.19.*, <022d1727f33ff90b3e1775125264e3023901952e, <d04c007047c88158141d9bd5eac761cdadd3782c, <=6.18.*, 6.6.131, 6.12.80, <f6484cadbcaf26b5844b51bd7307a663dda48ef6, 5.7, <=*, 6.1.168, 6.18.21, 03e9a0e05739cf872fee494b06c75c0469704a21) est présent sur votre parc.
  • Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
  • À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
  • Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.

Références

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