scsi: sd_zbc: Reject disks with too many zones

Overview

In the Linux kernel, the following vulnerability has been resolved:

scsi: sd_zbc: Reject disks with too many zones

sd_zbc_read_zones() computes the number of zones with 64-bit arithmetic and stores the result in the unsigned int nr_zones field of struct zoned_disk_info, silently truncating counts that exceed 32 bits. The truncated count is later used to size per-zone resources, while the device may still report more zones than fit.

Moreover, sd_zbc_report_zones() counts the reported zones with a signed int zone_idx, which overflows past INT_MAX. Reject devices reporting more than INT_MAX zones at scan time; such a device is not realistic for any medium that exists today, and accepting it produces inconsistent zone bookkeeping.

Affected

• Linux >= 89d9475610771b5e5fe1879075f0fc9ba6e3755f < d8791ae55d85dfaeafa20ea48365482a0cc5a107
• Linux >= 89d9475610771b5e5fe1879075f0fc9ba6e3755f < 0af16d8be3ec7ff28bb56a0da79c9aed66ac2c3b
• Linux >= 89d9475610771b5e5fe1879075f0fc9ba6e3755f < 3ddf8383b54456f19fd73d3cebed81bd250c7388
• Linux >= 89d9475610771b5e5fe1879075f0fc9ba6e3755f < b6ec0f79745967c751c85df373062c8d15e45fc4
• Linux 4.10

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.