CVE-2026-93191

/// Technical description

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

smack: fix incorrect task context in smack_msg_queue_msgrcv

The smack_msg_queue_msgrcv() function incorrectly checks

the permissions of the 'current' task instead of the

'target' task.

In the msgsnd() syscall path, if a receiver is already waiting,

the pipelined_send() optimization is used to push the message

directly to the receiver task:

ipc/msg.c`pipelined_send():

` smp_store_release(&msr->r_msg, msg)

In this case, the 'sender' (current) task performs the check

on behalf of the 'receiver' task (msr->r_tsk, passed as the

'target' parameter):

ipc/msg.c`pipelined_send():

` security_msg_queue_msgrcv(,, target := msr->r_tsk,,)

However, smack_msg_queue_msgrcv() ignores the 'target' and

checks 'current':

smack_msg_queue_msgrcv(…)

` smk_curacc_msq(isp, MAY_READWRITE); // current task

'current' MAY satisfy smack_msg_queue_msgrcv r/w requirement,

but 'target' (the receiver task) might NOT;

as a result

/// 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