Instituto Nacional de ciberseguridad. Sección Incibe
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CVE-2026-43376

Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
08/05/2026
Last modified:
12/05/2026

Description

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ksmbd: fix use-after-free by using call_rcu() for oplock_info<br /> <br /> ksmbd currently frees oplock_info immediately using kfree(), even<br /> though it is accessed under RCU read-side critical sections in places<br /> like opinfo_get() and proc_show_files().<br /> <br /> Since there is no RCU grace period delay between nullifying the pointer<br /> and freeing the memory, a reader can still access oplock_info<br /> structure after it has been freed. This can leads to a use-after-free<br /> especially in opinfo_get() where atomic_inc_not_zero() is called on<br /> already freed memory.<br /> <br /> Fix this by switching to deferred freeing using call_rcu().

Impact

Vector 3.x
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 9.80 CRITICAL
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x
9.80
Severity 3.x
CRITICAL

References to Advisories, Solutions, and Tools