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.

References 8

• git.kernel.org https://git.kernel.org/stable/c/251be2f6037fb7ab399f68cd7428ff274133d693
• git.kernel.org https://git.kernel.org/stable/c/45acbf154befedd9bc135f5e031fe7855d1e6493
• git.kernel.org https://git.kernel.org/stable/c/83ced3c206c292458e47c7fac54223abc7141585
• git.kernel.org https://git.kernel.org/stable/c/9326a1541e1b7ed3efdbab72061b82cf01c6477a
• git.kernel.org https://git.kernel.org/stable/c/9c671d4dbfbfb0d73cfdfb706afb36d9ad60a582
• git.kernel.org https://git.kernel.org/stable/c/d94be0a6ae9ade706d4270e740bdb4f79953a7fc
• git.kernel.org https://git.kernel.org/stable/c/e62251954a128a2d0fcbc19e5fa39e08935bb628
• git.kernel.org https://git.kernel.org/stable/c/eef5ef400893f8e3dbb09342583be0cdc716d566

Remediation