CVE-2025-40118: scsi: pm80xx: Fix array-index-out-of-of-bounds on rmmod

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-11-12 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: pm80xx: Fix array-index-out-of-of-bounds on rmmod Since commit f7b705c238d1 ("scsi: pm80xx: Set phy_attached to zero when device is gone") UBSAN reports: UBSAN: array-index-out-of-bounds in drivers/scsi/pm8001/pm8001_sas.c:786:17 index 28 is out of range for type 'pm8001_phy [16]' on rmmod when using an expander. For a direct attached device, attached_phy contains the local phy id. For a device behind an expander, attached_phy contains the remote phy id, not the local phy id. I.e. while pm8001_ha will have pm8001_ha->chip->n_phy local phys, for a device behind an expander, attached_phy can be much larger than pm8001_ha->chip->n_phy (depending on the amount of phys of the expander). E.g. on my system pm8001_ha has 8 phys with phy ids 0-7. One of the ports has an expander connected. The expander has 31 phys with phy ids 0-30. The pm8001_ha->phy array only contains the phys of the HBA. It does not contain the phys of the expander. Thus, it is wrong to use attached_phy to index the pm8001_ha->phy array for a device behind an expander. Thus, we can only clear phy_attached for devices that are directly attached.

Affected products

Linux kernel: from 5.4.293 before 5.4.301; from 5.10.237 before 5.10.246; from 5.15.181 before 5.15.195; from 6.1.136 before 6.1.156; from 6.6.89 before 6.6.112; from 6.12.26 before 6.12.53 — fixed in 5.10.246, 5.15.195, 5.4.301, 6.1.156, 6.12.53, 6.15

How to fix

Upgrade to a fixed version: Linux kernel 5.10.246, 5.15.195, 5.4.301, 6.1.156. Check the vendor advisory for mitigations.

References

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