CVE-2026-23193: scsi: target: iscsi: Fix use-after-free in iscsit_dec_session_usage_count()

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-14 · updated 2026-10-19
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: target: iscsi: Fix use-after-free in iscsit_dec_session_usage_count() In iscsit_dec_session_usage_count(), the function calls complete() while holding the sess->session_usage_lock. Similar to the connection usage count logic, the waiter signaled by complete() (e.g., in the session release path) may wake up and free the iscsit_session structure immediately. This creates a race condition where the current thread may attempt to execute spin_unlock_bh() on a session structure that has already been deallocated, resulting in a KASAN slab-use-after-free. To resolve this, release the session_usage_lock before calling complete() to ensure all dereferences of the sess pointer are finished before the waiter is allowed to proceed with deallocation.

Affected products

Linux kernel: from 3.1 before 5.10.250; from 5.11 before 5.15.200; from 5.16 before 6.1.163; from 6.2 before 6.6.124; from 6.7 before 6.12.70; from 6.13 before 6.18.10 — fixed in 5.10.250, 5.15.200, 6.1.163, 6.12.70, 6.18.10, 6.6.124

How to fix

Upgrade to a fixed version: Linux kernel 5.10.250, 5.15.200, 6.1.163, 6.12.70. Check the vendor advisory for mitigations.

References

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