Bug 2440630 (CVE-2026-23216)

Summary: CVE-2026-23216 kernel: scsi: target: iscsi: Fix use-after-free in iscsit_dec_conn_usage_count()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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A use-after-free flaw was found in the Linux kernel's iSCSI target subsystem. In the iscsit_dec_conn_usage_count() function, complete() is called while still holding the conn->conn_usage_lock spinlock. The waiting thread (such as iscsit_close_connection()) may wake up immediately and free the iscsit_conn structure before the current thread executes spin_unlock_bh(), resulting in a use-after-free when attempting to release the lock on already-freed memory.
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Description OSIDB Bzimport 2026-02-18 15:02:39 UTC 
In the Linux kernel, the following vulnerability has been resolved:

scsi: target: iscsi: Fix use-after-free in iscsit_dec_conn_usage_count()

In iscsit_dec_conn_usage_count(), the function calls complete() while
holding the conn->conn_usage_lock. As soon as complete() is invoked, the
waiter (such as iscsit_close_connection()) may wake up and proceed to free
the iscsit_conn structure.

If the waiter frees the memory before the current thread reaches
spin_unlock_bh(), it results in a KASAN slab-use-after-free as the function
attempts to release a lock within the already-freed connection structure.

Fix this by releasing the spinlock before calling complete().
Comment 1 Alexander B 2026-02-18 17:27:55 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026021800-CVE-2026-23216-6c63@gregkh/T