CVE-2026-72482

/// Technical description

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

gpib: fix double decrement of descriptor_busy in command_ioctl()

commit d1857f8296dc ("gpib: fix use-after-free in IO ioctl handlers")

introduced a descriptor_busy reference counter to pin struct

gpib_descriptor across IO ioctl operations. In command_ioctl(), the

error path inside the loop decrements descriptor_busy and breaks, but

execution then falls through to the unconditional decrement after the

loop, underflowing the counter to -1.

This re-enables the use-after-free that the original fix was meant to

prevent: a concurrent close_dev_ioctl() sees descriptor_busy == 0 on

an actively-used descriptor and frees it.

Remove the early decrement from the error path. The post-loop

decrement already handles all exit paths, matching the correct pattern

used in read_ioctl() and write_ioctl().

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References