CVE-2025-39795

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

block: avoid possible overflow for chunk_sectors check in blk_stack_limits()

In blk_stack_limits(), we check that the t->chunk_sectors value is a multiple of the t->physical_block_size value.

However, by finding the chunk_sectors value in bytes, we may overflow the unsigned int which holds chunk_sectors, so change the check to be based on sectors.

This vulnerability is rated Low for Red Hat Enterprise Linux because a possible integer overflow in the blk_stack_limits() function within the kernel's block layer could be exploited by an attacker with high privileges. Successful exploitation may lead to a denial of service or information disclosure. Triggering this vulnerability requires elevated privileges (ex. CAP_SYS_ADMIN) as modifying or creating block stacks is a privileged operation. If the bug is triggered, then there are potentially impacts to integrity and availability, in that a misalignment could result in an incorrect write to storage which in turn could cause some I/O errors, though they are unlikely to hang the system outright.

This affects Red Hat Enterprise Linux 7, 8, 9, 10, and Red Hat In-Vehicle OS.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.